Article

Magnesium in dairy cow nutrition: An overview

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Abstract

Background Magnesium (Mg) is an essential nutrient in animals and thus an adequate supply of dietary magnesium is important to safeguard animal health. It is generally accepted that the efficiency of Mg absorption is the critical determinant in Mg supply of ruminants. Insufficient absorption of Mg in ruminants leads to Mg deficiency which manifests in clinical signs such as tetany (grass tetany) or paresis (milkfever). Scope This overview aims to provide insight in the most relevant dietary factors that influence Mg absorption in ruminants and the state of the art knowledge on the mechanism of Mg absorption. Conclusions In practice, the use of manure to fertilize the soil is associated with an increased risk on grass tetany because it increases the K content of grass. A high K intake is the most important dietary factor that inhibits Mg absorption which entails the risk on Mg deficiency. The inhibitory effect of K on the effciency of Mg absorption can be counteracted by supplemental Mg. Magnesium oxide is commonly used to prevent Mg defiency but solubility of MgO varies greatly in practice. Thus, it is recommended to use only tested MgO sources. In the light of prevention of milkfever, supplementation in the form of Mg-chloride might be of interest as well. Due to its chloride ion, Mg chloride has a beneficial effect on the dietary cation-anion difference (DCAD).

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... One on farm factor increasing the relative risk of dark cutting in cattle is grazing perennial grass dominant pastures with magnesium concentration ≤ 0.24% dry matter (DM) (Loudon et al., 2018). Cattle grazing temperate pastures during winter and early spring are at risk of hypomagnesaemia as the pasture composition is typically grass dominant and the sward is rapidly growing, short, with a high water content, high crude protein levels, high potassium concentration but low magnesium and calcium concentration (Schonewille, 2013). Magnesium is an essential mineral in glucose metabolism through its role as an enzymatic cofactor for all major metabolic pathways, particularly those utilising high energy phosphate bonds, and through its action as a second messenger for insulin (Heaton & Elie, 1984;Paolisso, Scheen, d'Onofrio, & Lefebvre, 1990). ...
... Grass tetany index = (K/(Ca + Mg) ) in milliequivalents (MEq), Grass tetany indices greater than 2.2 suggest an increased risk of hypomagnesaemia (Schonewille, 2013). The pasture calcium to phosphorus ratio was calculated using the equation: ...
... DM. Grass Tetany Index means were less than 2.2 (MEq) however 12 of 42 pastures (29%) had levels greater than 2.2 suggesting increased risk of hypomagnesaemia (Schonewille, 2013). ...
Article
This study assessed the capacity of magnesium supplementation to reduce muscle glycogen loss, ultimate pH and increase plasma magnesium in pasture fed slaughter cattle. Beef cattle (n = 1075) from 14 farms were supplemented with or without magnesium pellets for 7–14 days prior to slaughter. Magnesium was allocated at 9.83 g of elemental magnesium per head per day, while the control diet was balanced to be isoenergetic and isonitrogenous, but contained no added magnesium. Groups of cattle (n = 44) were slaughtered at the same processing plant over two consecutive seasons, from August – September 2016 to May – July 2017. Magnesium supplementation increased muscle glycogen (P < 0.01) in cattle supplied from 2 of 14 farms, and increased plasma magnesium in 4 of 14 farms (P < 0.01). Magnesium supplementation had no effect on overall incidence of ultimate pH between the magnesium and control supplementation groups. The benefits of short term magnesium supplementation prior to slaughter was inconsistent for protecting muscle glycogen.
... g kg -1 dry matter (DM), depending on the species and physiological state) in pastures and feeds can result in rickets, osteoporosis and paresis (milk fever), and insufficient Mg concentrations (<0.40-2.50 g kg -1 DM, depending on the species and physiological state), especially when combined with high potassium (K) concentrations or low Ca concentrations, can result in paresis or grass tetany, which is potentially fatal (Suttle 2010;Schonewille 2013). ...
... Edible crops provide most of the Ca and Mg in the diets of humans and animals, either directly or indirectly (White et al. 2013); therefore, differences in the Ca and Mg concentrations of plant-derived food and feed can affect the health of humans and animals profoundly (Welch and Graham 2004;White and Broadley 2009;Broadley and White 2010;Rosanoff 2013;Joy et al. 2014). Unfortunately, human diets lacking sufficient Ca and Mg are estimated to be common in both developing and developed nations (Theobald 2005;Thacher et al. 2006;Broadley and White 2010;Joy et al. 2014), and grass tetany can be prevalent in spring pastures in many regions of the world (Schonewille 2013). To complement mineral supplementation and fortification of food and feed, agronomic strategies and crop-breeding programs have been advocated to increase the Ca and Mg concentrations in edible crops entering the human food chain (Welch and Graham 2004;White and Broadley 2009;Broadley and White 2010), while pasture management and cultivar development have been recommended to provide appropriate amounts of Mg and an appropriate K/(Ca + Mg) quotient of >2.2 (with concentrations expressed as meq g -1 DM) in the diets of livestock in the field (Hides and Thomas 1981;Sleper et al. 1989;White and Broadley 2009;Schonewille 2013). ...
... Unfortunately, human diets lacking sufficient Ca and Mg are estimated to be common in both developing and developed nations (Theobald 2005;Thacher et al. 2006;Broadley and White 2010;Joy et al. 2014), and grass tetany can be prevalent in spring pastures in many regions of the world (Schonewille 2013). To complement mineral supplementation and fortification of food and feed, agronomic strategies and crop-breeding programs have been advocated to increase the Ca and Mg concentrations in edible crops entering the human food chain (Welch and Graham 2004;White and Broadley 2009;Broadley and White 2010), while pasture management and cultivar development have been recommended to provide appropriate amounts of Mg and an appropriate K/(Ca + Mg) quotient of >2.2 (with concentrations expressed as meq g -1 DM) in the diets of livestock in the field (Hides and Thomas 1981;Sleper et al. 1989;White and Broadley 2009;Schonewille 2013). Because the choice of food crops and the plant species present in grasslands can be managed, these also provide strategies to address dietary Ca and Mg deficiencies, and it is, therefore, important to ascertain differences between angiosperm species with respect to the Ca and Mg concentrations in their edible tissues. ...
Article
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Insufficient calcium (Ca) or magnesium (Mg) in the diets of humans and animals has negative effects on health. Knowledge of the concentrations of Ca and Mg in edible crops can help inform the formulation of appropriate diets. There are large differences in shoot concentrations of both Ca ([Ca]shoot) and Mg ([Mg]shoot) between angiosperm orders. For example, relative to other angiosperms, commelinid monocot species generally have lower [Ca]shoot and [Mg]shoot; species from the Cucurbitales, Malvales and Brassicales generally have higher [Ca]shoot and [Mg]shoot; and species from the Oxalidales and Caryophyllales generally have higher [Mg]shoot but similar [Ca]shoot, which results in higher [Mg]shoot/[Ca]shoot quotients. In this paper the evolution of the combined traits of high [Mg]shoot and high [Mg]shoot/[Ca]shoot quotient in the Caryophyllales was resolved at the family level. All Caryophyllales families had high mean [Mg]shoot and [Mg]shoot/[Ca]shoot quotients, suggesting that both of these traits evolved in an ancient ancestor of all Caryophyllales families.
... Although the requirement for Mg can be met by common feed ingredients in animal diets, research and practice have shown benefits from supplementing Mg above the estimated minimum requirements in several food producing animals like pigs, poultry, and cows (as farm ruminants' representative). The practice of supplementing feedstuffs with Mg is widely used, with the primary aim to avoid Mg deficiency and then to improve animal performance (fertility and yield) and sometimes products' quality [4][5][6][7][8][9][10]. Table 1. ...
... It has been observed that fertilization of soil with MgO provided and increased Mg content in grass, but it was considered insufficient to prevent Mg deficiency. Instead of this approach, direct Mg supplementation in cows' diets is considered the best practice to prevent grass tetany and milk fever [5,8,9]. ...
... Indeed, at low K level in ruminal epithelial cells, the apical membrane potential provides a driving force for Mg uptake by the cells, whereas at high ruminal K level there is a depolarization of the membrane potential, thereby causing a reduction in Mg uptake by cells. It can be assumed that ruminal K concentration is linked to apical membrane potential [4,8,32]. This phenomenon was clearly observed in sheep, in which an increase of 1 g/kg DM in dietary K concentration decreased Mg absorption by 0.3% [33] (Figure 1). ...
Article
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Magnesium (Mg) is a mineral that plays an essential role as a cofactor of more than 300 enzymes. Mg in farm animals' and human nutrition is recommended to avoid Mg deficiency, ensure adequate growth and health maintenance. Mg supplementation above the estimated minimum requirements is the best practice to improve farm animals' performances (fertility and yield) and food products' quality, since the performance of farm animals has grown in recent decades. Mg supplementation in pigs increases meat quality and sows' fertility; in poultry, it helps to avoid deficiency-related health conditions and to improve meat quality and egg production by laying hens; in dairy cows, it serves to avoid grass tetany and milk fever, two conditions related to hypomagnesaemia, and to support their growth. Thus, Mg supplementation increases food products' quality and prevents Mg deficiency in farm animals, ensuring an adequate Mg content in animal-source food. These latter are excellent Mg sources in human diets. Sub-optimal Mg intake by humans has several implications in bone development, muscle function, and health maintenance. This review summarizes the main knowledge about Mg in farm animals and in human nutrition.
... Pastures are typically lush with a high water content, high protein and high potassium content but low in calcium and magnesium concentrations. These parameters can result in impaired magnesium intake and absorption in grazing cattle and cause a metabolic disease known as hypomagnesaemia (HypoMg) or grass tetany (Schonewille, 2013). magnesium is an essential dietary mineral and cofactor for numerous physiological and biochemical functions including nerve conduction, muscle contraction and adrenaline release. ...
... HypoMg reduces an animal's feed intake (Mayland, 1988) thus reduces energy intake and muscle glycogenesis. Furthermore HypoMg is likely to increase glycogenolysis due to increased neuromuscular hyperexcitability and increased adrenaline responsiveness to stress (Mayland, 1988;Schonewille, 2013). The grass tetany index or tetany ratio calculated using the equation potassium/calcium + magnesium expressed in milliequivalents (Kemp, & t Hart, 1957) is a commonly used indicator of whether cattle grazing pastures are at risk of developing HypoMg. ...
... The grass tetany index was calculated using the following equation which converts % diet dry matter to milliequivalents (MEq) (Kemp, & t Hart, 1957). Indices > 2.2 suggest an increased risk of HypoMg (Schonewille, 2013). ...
... Hypomagnesaemic tetany (HypoMgT), also known as grass tetany or grass staggers is caused by either an inadequate magnesium (Mg) supply to ruminants or reduced absorption of Mg in the rumen [1]. Signs of HypoMgT can include excitability, grinding of the teeth, salivation, a lack of coordination of muscle movement (e.g., a staggering gait), lying down or muscle spasms, and can lead to death within hours [2,3]. ...
... Preventative measures to reduce the risk of HypoMgT include: (i) direct to animal strategies such as administering Mg-containing bullets or boluses, and delivering Mg via drenches; (ii) in-feed strategies where Mg is included in a concentrate or total mixed ration, usually as part of a mineral premix; (iii) adding Mg to the drinking water; (iv) providing free-access Mg-containing salt licks and buckets; and (v) soil or plant-based strategies. Soil and plant-based strategies in particular are wide-ranging, and can include foliar and soil-based application of Mg fertilisers, dusting pasture with Mg-containing minerals [1,14], application of K fertilisers during winter, applying nitrogenous fertiliser with Mg if nitrogen is applied to pasture before grazing, grazing on permanent pastures in spring, and cutting and removing grass before grazing on paddocks with a grass tetany history [15]. Direct treatment of HypoMgT is usually via subcutaneous injection of magnesium sulphate [14] or magnesium hypophosphate often alongside calcium borogluconate. ...
Article
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Hypomagnesaemic tetany (HypoMgT) in ruminants is a physiological disorder caused by inadequate intake or impaired absorption of magnesium (Mg) in the gut. If it is not detected and treated in time, HypoMgT can cause the death of the affected animal. A semi-structured questionnaire survey was conducted from July 2016–2017 to assess farmers’ awareness of HypoMgT in cattle and sheep in the UK. The questionnaire was distributed to farmers at farm business events and agricultural shows, and through a collaborative group of independent veterinary practices to their clients. Farmers were asked about (i) the incidence of presumed HypoMgT (PHT); (ii) their strategies to treat or prevent HypoMgT; (iii) mineral tests on animals, forage and soil, and (iv) farm enterprise type. A total of 285 responses were received from 82 cattle, 157 mixed cattle and sheep, and 46 sheep farmers, of whom 39% reported HypoMgT in their livestock, affecting 1–30 animals. Treatment and/or prevention against HypoMgT was reported by 96% respondents with PHT and 79% of those without. Mineral tests on animal, forage, and soil was conducted by 24%, 53%, and 66% of the respondents, respectively, regardless of PHT. There was a highly significant association between the use of interventions to tackle HypoMgT and the incidence of PHT (p < 0.01). The top three treatment/prevention strategies used were reported as being free access supplementation (149), in feed supplementation (59) and direct to animal treatments (drenches, boluses and injections) (45) although these did vary by farm type. Although some (9) reported using Mg-lime, no other pasture management interventions were reported (e.g., Mg-fertilisation or sward composition). Generally, the results indicate that UK farmers are aware of the risks of HypoMgT. A more integrated soil-forage-animal assessment may improve the effectiveness of tackling HypoMgT and help highlight the root causes of the problem.
... Cow Start Calcium bolus was formulated in order to address the key nutritional challenges that transition cows face, in particular periparturient hypocalcaemia, by provision of available calcium sources, and sufficient rumen soluble magnesium to enhance calcium uptake [26][27][28]. By addressing calcium status, negative energy balance is also indirectly treated. ...
... Previous studies have demonstrated that both calcium sources used in the Cow Start Calcium bolus; calcium chloride and calcified marine algae, significantly increase blood calcium levels with 30 minutes of administration [29,30]. The Cow Start Calcium bolus also contains 50% more calcium than the calcium-only treatment along with 4g of Magnesium to enhance calcium uptake [26,28]. As calcium is required for muscle and nerve function, cows with low blood calcium status are reported to have an impaired ability to stand up, reduced mobility, and reduced dry matter intakes [1,6]. ...
... Apart from covering the nutritional requirements of cows with regard to energy components and protein, the proper mineral balance is very essential as well. In recent years more and more attention has been paid to the cation-anion balance which is also defined as DCAD (Dietary Cation-Anion Difference) or DCAB (Dietary Cation-Anion Balance) [Heron and Tremblay 2009, Hu and Kung 2009, Schonewille 2013, Goff and Liesegang 2014. This term defines the reciproctal ratio of positively-charged (cations) and negatively-charged (anions) elements [Hu and Kung 2009]. ...
... Postnatal paralysis is a common problem in the dairy cattle herds worldwide, including Poland [Mulligan et al. 2006, Łopuszańska-Rusek and Bilik 2007, Ramos-Nieves and Thering 2009, Patel et al. 2011, Schonewille 2013, Martin-Theresa and Wijlen 2014]. It is a metabolic disorder of the cows occurring in the period of 10 hours before up to 24-72 hours after a parturition [Patel et al. 2011]. ...
Article
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The experiment was performed on dairy cattle herds from two farms in Opole Province. The animals were in at least 75% Holstein-Friesians. During the dry period the cows were fed negative cation-anion balanced feed. Statistically important differences in frequency of milk fever were noticed between groups of animals fed the feed with and without anionic salts.
... Também é conhecido que a hiperglicemia em diabéticos aumenta a diurese, provocando elevação na filtração de Mg e consequentemente hipermagnesúria, enquanto as concentrações plasmáticas diminuem [14]. Em bovinos, a magnesemia é dependente da ingestão diária de Mg [8], podendo ser afetada por fatores que causam diminuição do consumo voluntário, como a acidose ruminal, cetose entre outras alterações que podem ser observadas no pós-parto [22]. Além do mais, um rigoroso controle do metabolismo renal de Mg, a fim prevenir alterações nos seus teores, provoca o au- mento na excreção urinária deste mineral em casos de hipermagnesemia e redução em casos de hipomagnese- mia [22]. ...
... Em bovinos, a magnesemia é dependente da ingestão diária de Mg [8], podendo ser afetada por fatores que causam diminuição do consumo voluntário, como a acidose ruminal, cetose entre outras alterações que podem ser observadas no pós-parto [22]. Além do mais, um rigoroso controle do metabolismo renal de Mg, a fim prevenir alterações nos seus teores, provoca o au- mento na excreção urinária deste mineral em casos de hipermagnesemia e redução em casos de hipomagnese- mia [22]. Estas observações associadas ao fato que os animais deste estudo receberem suplementação mineral na dieta, a fim de prevenir possível deficiência mineral das pastagens, justificam a falta de alterações no me- tabolismo do Mg em animais intolerantes a glicose. ...
Article
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Background: The post-partum period in dairy cows is accompanied by a low glucose metabolism in adipose tissue and skeletal muscle tissue, being glucose conducted to the milk production. In humans, low glucose metabolism is associated with metabolic syndromes, the high glucose levels reduce tubular reabsorption of Magnesium (Mg) and Calcium (Ca), leading to hypomagnesemia and hypocalcemia. These minerals are important to the dairy cow, as their decrease leads to diseases. The aim of this study was to evaluate the relationship between glucose metabolism rate with the urinary excretion of Ca and Mg in multiparous dairy cows during the post-partum period.Materials, Methods & Results: Twenty dairy cows were used from a commercial farm southern Brazil, in the semi-extensive system. Glucose tolerance tests were performed (TTG) on day 9 relative to calving. The cows were categorized into three groups according to the glucose metabolism rate (area under the glucose curve, glucose half-life and glucose consumption rate): High Glucose Metabolization (GA); Intermediate Glucose Metabolizing (GI); and Low Glucose Metabolization (GL). Blood and urine samples were collected on days 0, + 3, + 6, + 9, +16 and +2 3 in relation to calving for to determine the levels of Ca, Mg, insulin (Ins), non-esterified fatty acids (NEFA) and Glu. In urine was evaluated the excretion of Ca and Mg. The cows were milked twice a day (at 3:00 a.m. and 3:00 p.m.) and the milk yield (kg/cow) was recorded daily and averages were generated every five days from day 15 to day 60 postpartum. The statistical analyses were performed with the MIXED procedure to assess the main effect of group, time (in days) and their interaction by using version 9.2 SAS software. The influence of the different rates of glucose metabolism on milk production was observed, the GB group had a production than GH group (30.88 ± 1.44 kg vs 23.96 ± 1.43 kg, P < 0.01), but did not differ from GI. The GL group showed higher levels of Glu compared to GA (P < 0.05). The plasma Ca levels were higher in GL (P < 0.05) compared with GH. The NEFA, insulin, and excretion of minerals did not differ between groups (P > 0.05).Discussion: The low glucose metabolism in humans causes an increase in the excretion of Ca and Mg urine, however, in the animals studied, these changes were not observed. This result can be attributed to the fact that insulin resistance is transitory in dairy cattle. The higher glucose levels in the GL group are related due to the lower capacity of glucose entry in the peripheral tissues (adipose and skeletal muscle), which reflected in the higher milk production observed this group. However, the higher calcium concentrations were not expected, since the release of insulin by β-pancreatic cells is dependent on calcium. Possibly, these higher calcium levels in GB, are related to higher milk production, requiring a greater amount of calcium for the production of casein, increasing bone mobilization, intestinal absorption. The energy metabolites, non-esterified fatty acids and insulin, did not differ between groups, suggesting that the animals did not present different metabolic conditions. We conclude that multiparous dairy cows with low glucose metabolism rate (GB) have higher levels of glucose after delivery and increased milk production. The metabolism rate of glucose did not influence the excretion of the Ca and Mg minerals.
... Supplementing magnesium (Mg) to dairy cows is imperative for animal health outcomes on dairy farms, especially during calving and early lactation (Schonewille, 2013). In New Zealand, Mg is commonly supplemented via pasture dusting, drenching, water trough treatment, lick blocks and dusting of hay/silage (Grace et al. 2010). ...
... Indicating the importance of understanding the Mg content of all feed types. High Mg content during summer could be conserved or cut for supplements to be fed during the low Mg spring (McNaught et al. 1968) Potassium (K) and nitrogen (N) application has been found to interact with Mg uptake of pasture (Schonewille, 2013). Soil tests at Dalkeith Farms showed a QT K of 12, above the optimum level of 6-8. ...
Conference Paper
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Magnesium (Mg) supplementation of spring pastures is imperative for animal health outcomes on dairy farms. Traditionally supplementation via dusting or direct to animal has been used. A small plot trial was used to investigate the use of the soluble Mg fertiliser, kieserite (magnesium sulphate), to boost pasture magnesium contents to animal health levels. Two application timings and three rates of kieserite were applied to autumn saved pasture. Herbage testing was completed monthly during spring to determine uptake of Mg and soil tests were taken to determine changes in soil Mg. Magnesium in the herbage was in the range commonly seen in New Zealand pastures, and magnesium content increased during the trial period from July to November. However, the application of magnesium fertiliser, even at high rates, was not able to increase the magnesium content in the herbage into the animal health range until late spring. This is due to the low soil temperatures experienced during winter and early spring period at Dalkeith farm.
... Haptoglobin and ceruloplasmin are acute phase proteins that can be elevated in response to inflammation and infection in ruminants (Ceciliani, Ceron, Eckersall, & Sauerwein, 2012;Cray, Zaias, & Altman, 2009) and have also been used as a marker of stress in livestock (Giannetto et al., 2011;Lomborg, Nielsen, Heegaard, & Jacobsen, 2008;Salamano et al., 2008). High magnesium levels have also been associated with a reduced stress response (Hubbard, 1973) and low plasma magnesium has been associated with increased stress and muscle contraction, which may potentiate dark cutting (Ebel & Günther, 1980;Schonewille, 2013). Dehydration as a result of lack of available water or reluctance to consume water when stressed can result in dehydration and elevations in packed cell volume (PCV) and total protein (TP) (Hogan, Petherick, & Phillips, 2007;Jacob et al., 2006). ...
... Generally magnesium was lowest at day 70 post induction. The rationale for collecting plasma magnesium levels at different time points was that low plasma magnesium has been associated with increased stress and muscle contraction, (Ebel & Günther, 1980;Schonewille, 2013) which increases glycogenolysis in times of stress such as the pre-slaughter period. Furthermore high plasma magnesium has been shown to attenuate the stress response (Hubbard, 1973). ...
Book
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Cattle welfare is important from the perspective of the cattle themselves, marketing of beef product and improved production characteristics. This project aimed to assess time points in the supply chain from the time of induction to a feedlot through to slaughter to assess the relative levels of stress at these time points and the impact of cattle temperament on stress. Qualitative behavioural assessment was also investigated as an adjunctive or alternative method of assessing welfare. The impact of stress and temperament on cattle production and the potential for prediction of cattle performance was assessed and quantified. Data was collected from 240 cattle that originated from a single property from induction to slaughter. Although some measures of acute stress were greatest at slaughter, many measures of longer-term stress indicated that compared to induction this time point was less stressful for cattle. Cattle were shown to habituate to their environment in this study which may be a factor in their low expression of stress at slaughter. Temperament had an impact on production and carcase characteristics, however measurements taken in the feedlot and pre-slaughter periods are poor predictors of these traits. Results from this experiment can be used to develop indices for welfare assessment throughout the cattle supply chain.
... Genetic variation between and within plant species in their nutrient requirements can be exploited to develop crops for adverse soil conditions and restricted nutrient availability (Fageria et al. 2011, Veneklaas et al. 2012, Yang et al. 2012, White et al. 2012a, White 2013. Differences in the mineral composition of plant species, which are the foundation of food chains, and tissues within plants also have important consequences for the diets of herbivores and omnivores (White and Broadley 2009, Watson et al. 2012, Schonewille 2013, White et al. 2013b, White 2016b and affect their development, health and fecundity. Variation in the ionome of plants, which influences the mineral composition of forage, feed and food, will affect the ecology of natural communities and the health of farmed animals and humans. ...
Article
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The ionome is defined as the elemental composition of a subcellular structure, cell, tissue, organ or organism. The subset of the ionome comprising mineral nutrients is termed the functional ionome. A ‘standard functional ionome’ of leaves of an ‘average’ angiosperm, defined as the nutrient composition of leaves when growth is not limited by mineral nutrients, is presented and can be used to compare the effects of environment and genetics on plant nutrition. The leaf ionome of a plant is influenced by interactions between its environment and genetics. Examples of the effects of the environment on the leaf ionome are presented and the consequences of nutrient deficiencies on the leaf ionome are described. The physiological reasons for (1) allometric relationships between leaf nitrogen and phosphorus concentrations and (2) linear relationships between leaf calcium and magnesium concentrations are explained. It is noted that strong phylogenetic effects on the mineral composition of leaves of angiosperm species are observed even when sampled from diverse environments. The evolutionary origins of traits including (1) the small calcium concentrations of Poales leaves, (2) the large magnesium concentrations of Caryophyllales leaves, and (3) the large sulfur concentrations of Brassicales leaves are traced using phylogenetic relationships among angiosperm orders, families and genera. The rare evolution of hyperaccumulation of toxic elements in leaves of angiosperms is also described. Consequences of variation in the leaf ionome for ecology, mineral cycling in the environment, strategies for phytoremediation of contaminated land, sustainable agriculture, and the nutrition of livestock and humans are discussed.
... Applications of poultry litter decreased leaf Mg and Ca concentrations over time in grasses (Kayser and Isselstein, 2005;McClain and Blevins, 2009). Similarly, dairy manure applications often cause an accumulation of soil K (Schonewille, 2013), resulting in grass tetany ratios remaining above 2.2 in dairy manured pastures (Cherney et al., 2002). ...
Article
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Core Ideas Increased P availability increases leaf P and Mg in wheat, oat, and rye. The grass tetany ratio is improved with greater P availability in these species. Unlike cereal rye and oat, wheat increases shoot growth with high P levels. Winter annual species grown for forage are prone to mineral imbalances that could result in animal nutritional disorders, such as grass tetany. Adequate soil P has been found to be critical for the growth and adequate nutrient content of Mg, Ca, and K in other forages for grazing animals. This study examined the effect of P availability on growth and leaf nutrients in annual cereal grains commonly grown for winter forage. Winter wheat (Triticum aestivum L.), oat (Avena sativa L.), and cereal rye (Secale cereal L.) were grown hydroponically in greenhouse conditions in complete nutrient solutions with P treatments of 0, 200, 400, and 800 µmol L−1 P. After 32 d, plants were harvested and analyzed for P, Mg, Ca, and K content. Shoot growth of all three species increased from 0 to 200 µmol L−1 P; however, only wheat shoots increased incrementally with the other P treatment concentrations. Leaf P also responded incrementally to increased P treatments in all three species. Wheat and cereal rye exhibited increases in leaf Mg and improved grass tetany ratio from 200 to 400 µmol L−1 P, whereas oat showed these improvements from 0 to 200 µmol L−1 P treatments. This study suggests increased P availability could improve the grass tetany ratio, with or without increased shoot growth, in winter annual forage production on low P soils.
... Neznamená to však i vyšší utilizaci hořčíku v organizmu, a zejména v krvi přežvýkavců. Právě naopak, vysoký obsah dusíku a/nebo draslíku, zejména v jarní píci se již po relativně dlouhou dobu klade do příčinné souvislosti se sníženou utilizací Mg v organizmu pasoucích se přežvýkavců a následných příznaků pastevní tetanie (PT) - (Sjollema, 1930;Schonewille, 2013;Lunnant et al., 2018). Jedním z uvažovaných faktorů tohoto snížení je v některých případech výskyt zvýšených koncentrací amoniaku v ruminálním prostředí. ...
Article
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Knowledge and a possibility of influencing the magnesium–potassium interaction in soil, plant organs and animal organisms is one of the key factors in optimizing the animal nutrition. From this point of view, it is of great importance to predict the quantification of the above–mentioned interaction. Already in 1957 formulated Kamp and ’t Hart their predictive criterion in the form of a simple ratio of potassium and the sum of magnesium and calcium content in the plant material (feed). The authors have experimentally derived the "critical value" of the K/(Mg + Ca) ratio. Exceeding this value (2.2) it has resulted in exponential growth of the ruminants grazing tetanus incidence. But is this relationship and the calculation of "critical value" correctly used and interpreted by anyone? This topic is the subject of our contribution. It is rather curious and funny that even after over 60 years this relationship has not always been properly interpreted, and some authors confuse the values of K, Ca, and Mg concentrations, expressing these in molar ones, and not “on equivalent basis” (on moles of charge basis, in mol(+)/kg). The consequence of this misinterpretation is the declaration of double value of the Grass tetany Index (GTI) and therefore the twice unsubstantiated “hazard” of the analyzed feed. Based on the simple modification of the "orthodox" calculation of the grass tetany index, we have designed a simple relationship of calculation, in which it is practically impossible to mislead. It is based only on the knowledge of 3 numerical coefficients (1.53; 5 and 3) that multiply the relevant analytical concentrations of potassium, magnesium and calcium, expressed either in g / kg or as a percentage. This calculation has the form: GTI = 1.53 x K / (5 x Mg + 3 x Ca), where K, Mg and Ca are expressed in g/kg or, respectively, in percent. This relationship is practically identical to the GTI's "orthodox" calculation.
... The ruminal pH was also lowest in cows fed diet Fibre− , which may have favoured the increased Mg solubility. An increased Mg solubility is favourable for Mg absorbability (Schonewille et al., 2002;Schonewille, 2013;Martens et al., 2018). However, the potential benefits of a lower ruminal pH and a higher Mg solubility finally compromised Mg absorption in cows fed Fibre− . ...
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The potassium sensitive magnesium absorption through the rumen wall may be influenced by additional dietary properties, such as diet type, forage type or forage to concentrate ratio. These properties are likely associated to rumen passage kinetics modified by dietary fibre content. The study aimed to assess the effects of rumen passage kinetics on apparent Mg absorption and retention in lactating dairy cows fed modified levels of fibre. Six lactating Red-Holstein and Holstein cows, including four fitted with ruminal cannulas were randomly assigned to a 3 × 3 cross-over design. The experimental diets consisted of early harvested low NDF (341 g NDF/kg DM) and late harvested high NDF (572 g NDF/kg DM) grass silage (80% DM) and of concentrates (20% of DM). As the low-fibre diet was excessive in protein, a third high-fibre diet was formulated to be balanced in digestible protein with the low-fibre diet to avoid any eventual confounding effects of NDF and protein excess. All diets were formulated to contain iso-Ca, -P, -Mg, -K and -Na. Passage kinetics of solid and liquid phase of rumen digesta were evaluated using ruminal marker disappearance profiles. Cows fed the low-fibre diet had compared to the other diets, an up to 40% lower solid and 26% lower liquid phase volume of rumen digesta and a 10% numerically higher fractional rumen liquid passage rate. Rumen pH lost 0.6 units and Mg concentration in the rumen liquid phase tripled when cows were fed the low-fibre diet. Faecal Mg excretion was up to 14% higher in cows fed the low-fibre diet and Mg absorbability was 12% compared to up to 19% in other diets. Urinary Mg excretion in cows fed the low-fibre diet was half of the ones in the other treatments, but Mg retention was not affected. Dietary protein excess neither affected rumen passage kinetics nor Mg absorption and retention. Absorption of Mg was correlated with rumen liquid volume which both decreased with decreasing daily NDF intake (NDFi, 11.8 ± 2.4 l/kg NDFi). Consequently, daily Mg absorption decreased by 1.32 ± 0.28 g/kg decreasing NDFi. To conclude, in addition to the known antagonistic effect of dietary K, the present data indicate that Mg absorption was dependent from NDFi which modified rumen liquid volume, but was independent of dietary protein excess likely associated to low NDF herbages.
... Forages are rich in potassium (K), and K decreases the Mg absorption; so, with forages, the high Mg concentration must be also be given to an animal. Grass tetany occurs in the spring in cows by grazing on rapidly growing grass with a high K concentration [164]. Lactating cows fed with a positive dietary cation-anion difference (DCAD) rations have increased DMI and milk fat in a curvilinear response [165]. ...
Article
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For dairy cattle, the period involving a shift from late pregnancy to early lactation termed transition or periparturient is an excruciating phase. Health-related disorders are likely to happen in this time frame. Timely postpartum and metabolic adjustments to this new physical state demands correct management strategies to fulfill the cow’s needs for a successful transition to this phase. Among the management strategies, one of the most researched methods for managing transition-related stress is nutritional supplementation. Dietary components directly or indirectly affect the expression of various genes that are believed to be involved in various stress-related responses during this phase. Nutrigenomics, an interdisciplinary approach that combines nutritional science with omics technologies, opens new avenues for studying the genome’s complicated interactions with food. This revolutionary technique emphasizes the importance of food-gene interactions on various physiological and metabolic mechanisms. In animal sciences, nutrigenomics aims to promote the welfare of livestock animals and enhance their commercially important qualities through nutritional interventions. To this end, an increasing volume of research shows that nutritional supplementation can be effectively used to manage the metabolic stress dairy cows undergo during the transition period. These nutritional supplements, including polyunsaturated fatty acids, vitamins, dietary amino acids, and phytochemicals, have been shown to modulate energy homeostasis through different pathways, leading to addressing metabolic issues in transition cows.
... This results in a lower uptake of other cations, particularly of calcium (Ca), magnesium (Mg) and sodium (Na), in the herbage. A low uptake of Mg increases the risk of hypomagnesaemia (grass tetany) (Schonewille, 2013). The K/(Ca + Mg) relationship is often used as an indicator of tetany risk. ...
Article
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Herbage yield responses to K fertilizer application are variable in Norwegian grassland. Excessive K application may increase the risk of grass tetany (hypomagnesaemia) and milk fever (hypocalcaemia). We analysed a series of K fertilizer experiments on grassland with respect to their herbage yields and mineral composition. Our results show the importance of native soil K reserves when considering the need for K application. Soils with a high content of acid-soluble K showed no response to K fertilizer application. The critical K content in grass with respect to yield was estimated to be 17.7 g K/kg DM in the first cut and 20.3 kg K/DM in the second cut, while the critical K/N relationship was found to be 0.83 when a maximum yield reduction of 2.5% was used as a criterion. In these trials, soils with a high content of acid-soluble K had the greatest risk of grass tetany and the highest values of cation–anion balance. Application of potassium chloride had little effect on the cation–anion balance, and thereby the risk of milking fever, because there was a corresponding uptake of K and Cl ions.
... is an important mineral for in animals. Mg should be sufficient to metabolic activity and protect animal health (11). In cattle with theileriosis, there were decreased serum calcium and phosphorus concentrations in cattle infected with T. annulata in the present study which was also decreased in the previous studies (12). ...
Article
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The purpose of this study was to evaluate serum albumin, glucose, calcium (Ca), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), and phosphorus (P) in cows with naturally infected with Theileria annulata. The material of this study was a total of 15 cattle with different ages, breeds and genders diagnosed as theileriosis according to clinical and microscopical examination. According to statistical analyses of biochemical parameters; serum glucose, Ca, Co, Cu, Fe, Mg, and P concentrations were detected significantly low in cattle with theileriosis (P<0.001). In conclusion; mineral substance levels were altered in cattle naturally infected with Theileria annulata. Additionally to the classical treatment of theileriosis, administering mineral supplements including Ca, Co, Fe, Cu, Mg, and P to the animals is thought to be more useful in treatment.
... In order to maintain adequate relationships between elements in food, mineral compounds of Ca and/or Mg are supplemented, in particular in animal feed (Grunes, Welch 1989, VilleGas et al. 2009, schoneWille 2013, kleczkoWski et al. 2014. With respect to humans, Mg is more frequently supplemented. ...
Article
Relationships between elements in biomass of plants which make up a food chain are related to the physiological role of each element. These relationships can be disturbed by different factors, particularly those related to the availability of individual elements to plants. Adverse effects of distorted relationships between the calcium and magnesium concentrations in biomass, which are caused by the low content of the two elements in soil and intensive fertilisation, mainly the application of nitrogen fertilisers, can manifest themselves as the occurrence of different human and animal diseases. The purpose of the study was to determine the Ca and Mg abundance in cereal grain (rye, wheat, oats, barley, maize), potatoes and staple vegetables, and in plants which are mainly used as animal feed (grasses, lucerne, clover, beet), in the aspect of human and animal nutrient demand, particularly in terms of the Ca:Mg ratio. The grain of cereal plants, which is the main ingredient of many food products, was found to be poor in Ca and Mg; moreover, the Mg content was higher than that of Ca, i.e. the Ca:Mg ratio was lower than 1, with the exception of maize, in which the Ca:Mg ratio was higher than 1. The plants used as feed were richer in the analysed elements; nevertheless, according to the literature data, their Ca and Mg content in a unit of weight does not meet the animals’ demand for these components. The average content of both elements in average yields of different plant species cultivated on fertile soils established the Ca:Mg ratio at 1.1, whereas in plant yields from poor soils this ratio is 1.7. © 2017, Polish Society Magnesium Research. All rights reserved.
... and hypocalcaemia (milk fever) due to the inverse relationships between plant K concentration and Mg, Na and Ca concentrations (Schonewille, 2013). ...
Article
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Potassium fertilization in intensive grassland systems is particularly important on sandy soils with limited K storage capacity. A 3-year plot experiment was conducted in south-western Australia to determine the critical K concentration in herbage dry matter (DM) of annual and Italian ryegrass required to achieve 0.95 of the maximum yield, under best-practice grassland management. A factorial design was employed with eight fertilizer K rates (range 0–360 kg ha−1 year−1) and two ryegrass species replicated four times, on a sandy soil site managed over 7 years to deplete mean soil Colwell K concentration to 42 mg/kg. Herbage was defoliated six times per year at the 3-leaf stage of regrowth. Herbage DM yield, macronutrient and micronutrient concentrations were measured at each defoliation. Dry-matter yield increased significantly (p < .001) with increasing levels of K fertilizer in all 3 years and the effect was curvilinear, while 0.95 of the maximum herbage DM yield was achieved at an annual K fertilizer application rate of 96, 96 and 79 kg/ha respectively. At these K fertilizer application levels, the mean K concentration of herbage DM over the 3 years was derived to be 11.4, 12.7 and 11.2 g/kg respectively. Sodium, magnesium and calcium concentrations of herbage DM all declined significantly (p < .001) as the K concentration increased. Grassland producers on sandy soils should target a K concentration in herbage DM of 16 g/kg for annual ryegrass and Italian ryegrass-dominant swards to ensure K availability is not limiting herbage production.
... Low plasma magnesium levels (e.g., between 0.4 and 0.8 mmol/L; Schonewille, 2013) ing breath (caused by exhalation of ketone bodies), and may also result in reduced appetite and depression of intake, reduced milk yield, changes in behavior, and in cases of prolonged energy deficit, weight loss. The costs associated with ketosis include ketosis treatment, increased risk of other diseases, risk of poorer reproductive performance, and higher risk of culling in early lactation (Gordon et al., 2013). ...
Article
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Metabolic disorders are disturbances to one or more of the metabolic processes in dairy cattle. Dysfunction of any of these processes is associated with the manifestation of metabolic diseases or disorders. In this review, data recording, incidences, genetic parameters, predictors, and status of genetic evaluations were examined for (1) ketosis, (2) displaced abomasum, (3) milk fever, and (4) tetany, as these are the most prevalent metabolic diseases where published genetic parameters are available. The reported incidences of clinical cases of metabolic disorders are generally low (less than 10% of cows are recorded as having a metabolic disease per herd per year or parity/lactation). Heritability estimates are also low and are typically less than 5%. Genetic correlations between metabolic traits are mainly positive, indicating that selection to improve one of these diseases is likely to have a positive effect on the others. Furthermore, there may also be opportunities to select for general disease resistance in terms of metabolic stability. Although there is inconsistency in published genetic correlation estimates between milk yield and metabolic traits, selection for milk yield may be expected to lead to a deterioration in metabolic disorders. Under-recording and difficulty in diagnosing subclinical cases are among the reasons why interest is growing in using easily measurable predictors of metabolic diseases, either recorded on-farm by using sensors and milk tests or off-farm using data collected from routine milk recording. Some countries have already initiated genetic evaluations of metabolic disease traits and currently most of these use clinical observations of disease. However, there are opportunities to use clinical diseases in addition to predictor traits and genomic information to strengthen genetic evaluations for metabolic health in the future.
... While relatively little is known of hypocalcemia and hypomagnesemia (low blood serum levels of calcium and magnesium respectively) in non-domesticated ungulates, they are a common and serious problem in domesticated cattle and sheep in the springtime (Schonewille 2013;Silk 2013). Studies with semi-domesticated reindeer have also shown that hypomagnesemia is common in the late winter and early spring (Hoff et al. 1993;Ropstad et al. 1997). ...
Article
1.Overbrowsing by ungulates is a major cause of poor aspen stand regeneration across North America and Eurasia. In general, factors driving ungulate browser preferences include concentrations of plant secondary compounds and the nutritional composition (non-structural carbohydrates, protein, and minerals) of foliage. While each of these phytochemical factors has been shown to independently influence ungulate preference, the relative impact of each factor is unknown, as no study to date has examined them simultaneously.
... Magnesium (Mg) was already recognized as an essential nutrient near 1925 [1]. For example, 60 % of the Mg is in a human bone with totally 25g, where it plays a center role in skeletal development [2]. ...
Article
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Although magnesium (Mg) is one of the most important nutrients, involving mainly in many enzyme activities and the structure stabilization of tissues, it was recognized as a forgotten macronutrient ion by botanists and agriculturists in the last decades, because that they did not regard Mg deficiency (MGD) in plants as a severe problem to our health. However, recent studies surprisingly showed that Mg contents in historical cereal seeds significantly declined with time, and 2/3 people surveyed in developed countries could not uptake enough Mg daily. Therefore, the response mechanisms to the MGD and how to increase Mg contents in plants may be two urgent realistic problems. In this review, we discussed several aspects of the MGD in plants, including the phenotypic and physiological changes, the Mg2+ homeostasis in cells controlled by Mg2+ transporters, the signaling of the MGD, the interactions between Mg2+ and other ions, and Mg’s roles in plant second metabolisms. We hope that these will improve us to understand the effluence of the MGD on plant growth and development, and will help crop breeding for Mg enrichment.
... 79 However, no effect on Mg 2+ concentrations was reported by low K + supply, suggesting that the antagonistic effect of K + on Mg 2+ uptake is more marked than that of Mg 2+ on K + uptake. 80 K + , in addition to competing for apoplast binding sites with Mg 2+ , possibly competes for transporters. For example, two members of class II of K + transporters (OsHKT2; 4 and TaHKT2; 1) also transported Mg 2+ in Xenopus laevis oocytes. ...
Article
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Magnesium (Mg) is one of the most important nutrient, involves mainly in plant growth and development. However, the importance of Mg has been ignored in recent decades by the people, who generally regard Mg in plants as an unsevere problem for human life. Recent studies have shown, surprisingly, that Mg contents in historical cereal seeds have markedly declined over time, and two-thirds of people surveyed in developed countries received less than their minimum daily Mg requirement. Thus, it is most important for improving the development of Mg homeostasis mechanisms and its use efficiency in plants. Many environment and intracellular factors affect Mg homeostasis in plants, such as Mg deficiency and toxicity, high temperature, drought, high light, low pH, and antagonism ions. The most gratifying things are that some Mg transporters and signal factors response to Mg stresses were discovered in the last years, including Mg²⁺/H⁺ exchanger 1 (MHX1), GA negative proteins (DELLAs), ABA insensitive 1 (ABI1), and CBL (calcineurin B-like proteins)-interacting protein kinase complexes (CBL–CIPKs), and omics helped in discovering novel opinions. Those new discoveries may improve genetic modification of crops for efficient biofortification of Mg.
... Major implications in animals (ruminants) growth, body development and good function, reproduction etc. were assigned to minerals as Mg (Schonewille, 2013), Fe (Herdt and Hoff, 2011;McClure, 2008), Zn (Griffiths et al., 2007), Mn (Uchida et al., 2001;Waldenstedt, 2006). For example, prudent supplementation of dietary trace mineral for lactating dairy cows (mg/kg DM) is assured by adding 4 g/kg Mg, 40 mg/kg Zn, 10 mg/kg Cu and 40 mg/kg Mn (McDowell et al., 2002). ...
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The study aimed the diversification of fodder yeast assortments with viable economic effects while reducing the environment pollution by capitalization of wastewaters with high monosaccharides content from pulp and paper industry and residual whey from milk industry. Using the Response Surface Methodology the fabrication recipe has been optimized according to an experimental program based on a mathematical model with biomass, protein and residual sugar as response functions. The culture medium for a mix of Candida utilis and Candida pseudotropicalis strains was composed by 25 g/L fermentable monosaccharides provided by pulp and paper wastewaters and whey, MgSO4 0.8 g/L, ZnSO4 1.2 g/L, MnSO4 1.0 g/L, FeSO4 0.8 g/L and up to 1053 mg/L nitrogen and 422 mg/L phosphorous from (NH4)2SO4 and (NH4)2HPO4. In these conditions, the biomass gain was of 6.45 g/L and the protein content reached a value of 50.64% while the amount of the residual sugar decreased at 2.08 g/L.
... This was unexpected as the range in plasma magnesium concentrations suggested that at least some of the cattle were hypomagnesaemic [35]. Magnesium is reported to reduce the catecholamine effect during acute stress [54,55] as well as reduce neuromuscular stimulation via its antagonism of calcium [56,57]. Catecholamine release from activation of the sympathetic nervous system decreases plasma magnesium concentrations [58][59][60]. ...
Article
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This study considered the relationship between pre-slaughter stressors and plasma biomarkers in 488 pasture-raised cattle across two experiments. The design aimed to test groups consisting of steer only, heifer only, and mixed sex cattle under direct kill versus rested (14 days in abattoir holding paddocks) protocols. In Experiment One, cattle were sourced from four farms, and transported by trucks and ships on the same day. In Experiment Two, cattle were sourced from four farms where a comparison was made between marketing via two commercial saleyards or direct farm gate consignment to abattoir. Blood samples were collected at exsanguination for subsequent analyses and relation to meat quality attributes. Muscle damage, as indicated by creatine kinase, is the biomarker most correlated to ultimate pH and muscle glycogen concentrations. A two-week rest period is effective for lowering this enzyme and improving muscle glycogen concentration. Although the cattle was subjected to a range of stress inducing treatments, we found that plasma biomarkers alone appeared insufficient for use as diagnostic stress indicators.
... These can result from insufficient dietary Mg and Ca as well as high levels of dietary potassium (K), which can interfere with the uptake of Mg and Ca in the gut. Deficiency of these nutrients in livestock can lead to conditions including milk fever, grass tetany, and staggers (Suttle, 2010;Schonewille, 2013;Friend et al., 2020), which can induce coma and death of affected animals if not treated. ...
Article
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Magnesium (Mg) and calcium (Ca) are essential mineral nutrients poorly supplied in many human food systems. In grazing livestock, Mg and Ca deficiencies are costly welfare issues. Here, we report a Brassica rapa loss-of-function schengen3 (sgn3) mutant, braA.sgn3.a-1, which accumulates twice as much Mg and a third more Ca in its leaves. We mapped braA.sgn3.a to a single recessive locus using a forward ionomic screen of chemically mutagenised lines with subsequent backcrossing and Linked-Read sequencing of second back-crossed, second filial generation (BC2F2) segregants. Confocal imaging revealed a disrupted root endodermal diffusion barrier, consistent with SGN3 encoding a receptor-like kinase required for normal formation of Casparian strips, as reported in thale cress (Arabidopsis thaliana). Analysis of the spatial distribution of elements showed elevated extracellular Mg concentrations in leaves of braA.sgn3.a-1, hypothesised to result from preferential export of excessive Mg from cells to ensure suitable cellular concentrations. This work confirms a conserved role of SGN3 in controlling nutrient homeostasis in B. rapa, and reveals mechanisms by which plants are able to deal with perturbed shoot element concentrations resulting from a "leaky" root endodermal barrier. Characterisation of variation in leaf Mg and Ca accumulation across a mutagenised population of B. rapa shows promise for using such populations in breeding programmes to increase edible concentrations of essential human and animal nutrients.
... (hypomagnesaemia) in ruminant livestock is a serious issue for the agricultural sector and accounts for a significant number of animal deaths annually. It is caused by a diet deficient in Mg, or due to an imbalance in the supply of Mg in comparison to other mineral cations 1 . Hypomagnesaemia is likely to be responsible for lower-productivity and diminished well-being in more animals in a herd compared to those displaying acute symptoms, given that herds/flocks generally receive a common diet 2,3 . ...
Article
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Magnesium (Mg) is essential for animal health. Low Mg status (hypomagnesaemia) can be potentially fatal in ruminants, like cattle and sheep, and is widespread in Europe with economic impacts on farming. The application of Mg-rich agricultural lime products can help to ensure pasture forage consumed by animals contains sufficient Mg and, in areas of low pH, has the dual benefit of reducing soil acidity to levels best suited for grass production. This aim of this study was to determine if Mg-rich lime products could be used in a more effective manner in agricultural production systems. Potential resources of carbonate rocks (limestone, dolostone and chalk) in the UK, and their Mg:Ca status were identified, using datasets from the British Geological Survey (BGS). These data were combined with the locations of agricultural lime quarries, and areas where soils are likely to be deficient in Mg and/or require liming. Areas of potential demand for Mg-rich agricultural lime include areas in south east Wales, the Midlands and North East England. Although, areas where this may be an effective solution to low soil Mg values are restricted by the availability of suitable products. Conversely, areas of low soil pH in England and Wales are often found close to quarries with the ability to supply high Ca limes, suggesting that the low rates of lime use and liming is not due to supply factors. This study provides information that can help to guide on-farm decision making for use of Mg-rich and other lime resources. This could be used in conjunction with other options to reduce risks of Mg deficiency in livestock, and improve soil pH.
... Por su parte, Cu y Mg también se encuentran relacionados al desempeño reproductivo del ganado lechero, puesto que sus deficiencias han sido vinculadas con retrasos de crecimiento, anorexia, inmunodepresión y anemias (Ingraham et al., 1987;Graham, 1991;Matsui, 2007). La deficiencia de Mg (<4 umol/L) puede ocasionar infecciones uterinas postparto relacionadas con celos repetidos y, en casos extremos, con hipocalcemia puerperal (Ingraham et al., 1987;Schonewille, 2013). Por otra parte, anemias derivadas de la deficiencia de Cu (<4 umol/L), han sido relacionadas con depresiones de la función ovárica e infertilidad postparto en vacas lecheras (Wagner y Hansel, 1969;Kappel et al., 1984;Suttle, 1993). ...
Thesis
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El objetivo del estudio fue determinar el efecto de la aplicación de un suplemento mineral inyectable basado en fósforo (P), selenio (Se), potasio (K), magnesio (Mg) y cobre (Cu), sobre la eficiencia productiva, reproductiva y respuestas fisiológicas de vacas Holstein estresadas por calor. Dieciséis vacas fueron asignadas a uno de dos tratamientos usando un diseño de bloques completos al azar. El número de lactancias (una o más de una) fue considerado como factor de bloqueo. Los tratamientos fueron: Suplementado (SUP; n = 8), vacas tratadas con minerales, y Testigo (TES; n = 8), vacas no tratadas. La temperatura ambiental y la humedad relativa se midieron para estimar el índice temperatura-humedad (ITH). Variables productivas y fisiológicas fueron registradas dos veces al día (05:00 y 17:00 h), dos días por semana, durante 6 semanas. Para evaluar la eficiencia reproductiva, todas las vacas fueron sometidas a un programa de inseminación artificial a tiempo fijo (IATF) utilizando el protocolo de sincronización CIDR-Synch. Durante y después de la aplicación del protocolo, variables asociadas a la actividad ovárica y la concentración de hormonas esteroidales fueron registradas. El diagnóstico de gestación se realizó 35 d después de la IATF. Durante el experimento, todas las vacas permanecieron bajo condiciones de estrés por calor (p. ej., temperatura = 29.8 ± 4.7 °C, ITH = 79.4 ± 4.3 unidades); sin embargo, el suplemento mineral parenteral impactó positivamente (P < 0.05) variables fisiológicas relacionadas con la respuesta al mismo disminuyendo la frecuencia respiratoria y temperaturas de pierna y ubre. Para variables productivas, el suplemento mineral aumentó sólidos no grasos, densidad, proteína y lactosa en leche, disminuyendo su punto de congelación (P < 0.05). En el aspecto reproductivo, el suplemento mineral aumentó (P < 0.05) las concentraciones séricas de progesterona y estrógenos. Adicionalmente, la tasa de concepción de vacas suplementadas con minerales resultó mejor que la de vacas no suplementadas (P < 0.05). En conclusión, los resultados sugieren que la aplicación de un suplemento mineral a vacas Holstein estresadas por calor, podría contrarrestar algunos efectos negativos del mismo sobre la fisiología y las habilidades productiva y reproductiva del ganado lechero.
... High use of nitrogenous fertilisers has been associated with an increased risk of grass tetany (Kemp 1960;Mayland and Grunes 1974;Mayland 1988;Martens and Schweigel 2000). The impact of increasing crude protein on magnesium absorption is inconsistent; thus, the mechanism is likely via shifting the forage to a more grass-dominant, less cloverbased composition (Suttle 2010;Schonewille 2013). While fertilisation with nitrogen will directly increase the sward Mg concentration (Mayland and Grunes 1974), the effects are typically negated due to a reduced clover composition. ...
Article
High lamb mortality continues to be a significant economic and welfare problem within the Australian sheep industry, with 20–30% of lambs born in commercial flocks dying mostly within 3 days of birth. Clinical hypocalcaemia and hypomagnesaemia cause ewe mortality, and, subsequently, either fetal or lamb death, but it is not known whether subclinical deficiencies of calcium (Ca) and magnesium (Mg) compromise lamb survival. This review considers the potential mechanisms through which Ca and Mg deficiencies may influence lamb survival, and factors influencing the risk of deficiency. Pastures grazed by lambing ewes may be marginal in calcium (Ca; <4 g/kg DM) and magnesium (Mg; <0.9 g/kg DM) but also have a high dietary cation–anion difference (>12 meq/100 g DM) and high concentrations of potassium (K; >30 g/kg DM) and nitrogen. In young cereal crops, odium concentrations are also often low (<0.9 g/kg DM). This combination of minerals and other nutrients creates an imbalance in supply and increases susceptibility to acute Ca (hypocalcaemia) and Mg (hypomagnesaemia) deficiency. Calcium is required for smooth muscle function and has a direct role in uterine contraction, so may influence the duration of parturition. Low Ca and Mg intake both influence insulin release and sensitivity, low Mg results in poor glycaemic control and insulin resistance by impairing both insulin secretion and its action on peripheral tissues, also potentially altering the duration of parturition as well as risk of metabolic disease. Magnesium is also a neuroprotectant that slows the neuronal damage during hypoxia and has been linked with thermogenesis in offspring and increased immunoglobulins in colostrum. These functions indicate potential importance in improving the ease of parturition and improved ability of the newborn lamb to thermoregulate and survive after birth. Subclinical Ca and Mg deficiencies commonly occur in 20% of lambing ewes grazing temperate pastures, so further studies are warranted to investigate whether correction of these deficiencies can improve lamb survival.
... Similarly, Se supplementation was associated with higher daily milk yield in Holstein cows [10]. Recent findings also demonstrate that deficiency of essential minerals, especially Ca [11], P [12], and Mg [13], is also associated with impaired lactation and reduced milk yield. However, the existing data on the association between trace element and mineral status of dairy cows and milk productivity are rather contradictory. ...
Article
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The objective of the present study was to assess hair and serum trace element and mineral levels in dairy cows in relation to daily milk yield. A total of 70 healthy 5–6-year-old Simmental cows were divided into two groups (n = 35) with high and low daily milk yield using median as a cut-off value. Hair and serum trace element and mineral content was evaluated using inductively coupled plasma mass-spectrometry. A nearly twofold difference in daily milk yield (43.8 ± 9.7 vs 21.3 ± 7.1 L/day, p < 0.001) was significantly associated with 11% lower hair Cu (p = 0.043) and 35% higher Se levels (p = 0.058) content when compared animals with lower daily milk yield. Serum trace element levels were found to be more tightly associated with milk productivity in dairy cows. Particularly, serum levels of Se and Zn were found to be 73 and 35% higher in cows with higher milk productivity in comparison to animals with lower milk production, respectively. Serum Co levels also tended to increase with higher milk productivity. Serum minerals including Ca, Mg, and P were also found to be higher in highly productive cows by 6%, 14%, and 71%, respectively. The overall regression model based on serum trace element and mineral levels accounted for 38% of daily milk production variability. Generally, improvement of essential trace element and mineral supply, as well as prevention of copper overload in dairy cows, may be considered the potential tool for modulation of milk productivity.
... The cause of the difference in Mg levels in BX cattle serum in this study is not known with certainty; however, it is likely related to differences in feed intake in some of these physiological statuses. Schonewille (2013) stated that the level of Mg in serum is closely related to the intake/content of Mg in the feed and its absorption in the digestive tract of cattle. A different report was put forward by Fadlalla et al. (2020) who stated that the concentration of Mg in the prepartum period was higher than that in the postpartum period and there tended to be no change during lactation. ...
... It is worth noting that the difference between pregnant and nonpregnant cows at sample collection was only 0.03 mmol/L; however, a significant difference may still indicate that Mg is an important mineral worth discussing in transition cows. Magnesium is an essential nutrient and is a co-factor for many enzymes, including those affecting energy metabolism and protein synthesis [30]. Hypomagnesemia reduces parathyroid hormone secretion and reduces tissue sensitivity to parathyroid hormone, which impairs Ca metabolism [31]. ...
Article
The objective of this study was to examine the relationship between early postpartum nutritional and metabolic profiles in lactating dairy cows and subsequent pregnancy to first artificial insemination (AI), pregnancy by 150 d in milk (DIM) and pregnancy loss after first AI. A blood sample was collected between 2 and 14 (median = 9) DIM from 869 lactating Holstein cows to determine serum concentrations of metabolites, minerals, and enzymes. Associations between metabolites and fertility were determined using an adjusted odds ratio (OR). Overall, pregnancy to first AI, pregnancy by 150 DIM and pregnancy loss after first AI were 37.9, 65.8 and 11.2%, respectively. Compared to cows pregnant to first AI, non-pregnant cows had higher (P < 0.05) serum concentrations of aspartate aminotransferase (AST; 92.3 ± 1.6 vs. 84.6 ± 2.0 U/L), non-esterified fatty acid (NEFA; 0.73 ± 0.02 vs. 0.54 ± 0.02 mmol/L), and haptoglobin (0.77 ± 0.04 vs. 0.60 ± 0.05 g/L), and lower (P < 0.05) serum concentrations of Mg (0.86 ± 0.02 vs. 0.89 ± 0.02 mmol/L) and cholesterol (2.1 ± 0.03 vs. 2.4 ± 0.04 mmol/L). Cows non-pregnant by 150 DIM had lower (P < 0.05) serum concentration of Mg (0.86 ± 0.02 vs. 0.88 ± 0.02 mmol/L) and higher serum concentration of haptoglobin (0.82 ± 0.1 vs. 0.63 ± 0.09 g/L) than cows pregnant by 150 DIM. Cows that lost their pregnancy after first AI had greater serum concentrations of haptoglobin than those that did not undergo pregnancy loss (1.1 ± 0.09 vs. 0.5 ± 0.05 g/L; P < 0.01). The odds of pregnancy to first AI (OR; 95% confidence interval [CI]) decreased with increased concentrations of AST (OR = 0.99; 95% CI = 0.98–1.00), NEFA (OR = 0.54; 95% CI = 0.37–0.79) and haptoglobin (OR = 0.80; 85% CI = 0.66–0.96) and with decreased concentrations of Mg (OR = 3.24; 95% CI = 1.09–9.62) and cholesterol (OR = 1.24; 95% CI = 1.02–1.54). Decreased concentrations of Mg (OR = 3.06; 95% CI = 1.02–9.20) and increased concentrations of haptoglobin (OR = 0.92; 95% CI = 0.69–0.97) were associated with lower odds pregnancy by 150 DIM. Only increased concentrations of haptoglobin (OR = 1.58; 95% CI = 1.13–2.20) were associated with increased odds of pregnancy loss after the first AI. In summary, greater early postpartum serum concentrations of AST, NEFA and haptoglobin were associated with reduced fertility, but the opposite was observed for serum concentrations of Mg and cholesterol. In addition, serum concentrations of haptoglobin were positively associated with pregnancy loss.
... Magnesium (Mg) is an essential element for ruminant nutrition, required for normal nerve and muscle function, bone formation and as a cofactor for enzymatic reactions in metabolic pathways (Schonewille 2013). Animals are unable to mobilise large amounts of Mg from the bone or soft tissues, and therefore maintaining adequate plasma Mg concentrations relies almost entirely on Mg intake and absorption (Martens and Stumpff 2019). ...
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Aims An Italian ryegrass cultivar (Lolium multiflorum Lam. cv. Bb2067), selected and bred for increased leaf magnesium (Mg) concentration in the 1970s, reduced the incidence of hypomagnesaemia in sheep under experimental grazings. Here, we report evidence from archival experiments showing that cv. Bb2067 had consistently greater Mg concentrations at multiple sites. We also aimed to quantify variation in leaf Mg concentration among modern perennial ryegrass (Lolium perenne L.), hybrid ryegrass (Lolium perenne × multiflorum), and tall fescue (Festuca arundinacea Shreb.) cultivars. Methods Data are reported from unpublished 1980s field-plot experiments for cv. Bb2067 and contemporaneous reference cultivars, sown at two UK locations in 1983 and 1984, and from 397 cultivars of modern forage grass in 13 UK-based breeding experiments sampled in spring 2013. Results Across sites, years and cuts, cv. Bb2067 had a consistently greater leaf Mg concentration and lower potassium (K) concentration and forage tetany index (FTI) than reference cultivars in the 1980s experiments. Seasonal variation in leaf Mg and K concentrations and FTI were observed in the 1980s experiments, with K concentrations being generally greatest and Mg concentrations smallest in spring. Among modern forage grasses, there was large variation in leaf Mg concentration (up to 6.3-fold) and FTI (up to 2.1-fold), both within and between species, which varied independently of yield. Among a subset of hybrid ryegrass cultivars, there is evidence that the high Mg trait is already present in some modern breeding lines, albeit previously unreported. Conclusions The variation in leaf Mg concentration and FTI among old and new cultivars shows there is considerable potential to breed forages with improved mineral quality to improve livestock health, potentially without compromising yield or other nutritional traits.
... The high concentration of minerals in S. fusiforme might be able to provide a natural source of ruminant feed ingredients Fig. 1. Calcium (Ca 2+ ) and magnesium (Mg), in particular, are co-factors for many enzymes and are involved in energy metabolism, protein synthesis, the proper functioning of skeletal muscles, and bone growth 11 . An abundance of essential trace minerals, such as iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu), are also important for the maintenance of normal physiological functions in the body 12 . ...
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Sargassum fusiforme, which is a type of brown algae, can provide fiber and minerals to ruminant diets. In this study, dried S. fusiforme was tested in vitro at four different doses 1, 3, 5, and 10% of the total ration for its effect on ruminal fermentation characteristics, and gas profiles when incubated for 72 h. At a level of 1 and 10%, S. fusiforme supplementation augmented total volatile fatty acid (VFA) concentrations compared to that with 0% supplementation. In addition, total gas, methane, and carbon dioxide emissions significantly decreased at 3 and 24 h of incubation at this dose. An in situ trial was performed for 72 h with S. fusiforme to evaluate it as a potential feed ingredient by comparing its degradation parameters with timothy hay (Phleum pretense). 1 H nuclear magnetic resonance spectroscopy profiling was used to identify and quantify metabolites of S. fusiforme. Mannitol, guanidoacetate and ethylene glycol were largely accumulated in S. fusiforme. Moreover, nutritious minerals for feed ingredients were present in S. fusiforme. Whereas a high concentration of arsenic was found in S. fusiforme, it was within the allowable limit for ruminants. Our results suggest that S. fusiforme could represent an alternative, renewable feed ingredient for ruminant diets, with nutritional, as well as environmental, benefits.
... Magnesium (Mg) de ciency (hypomagnesaemia) in ruminant livestock is a serious issue for the agricultural sector and accounts for a signi cant number of animal deaths annually. It is caused by a diet de cient in Mg, or due to an imbalance in the supply of Mg in comparison to other mineral cations 1 . Hypomagnesaemia is likely to be responsible for lower-productivity and diminished well-being in more animals in a herd compared to those displaying acute symptoms, given that herds/ ocks generally receive a common diet 2,3 . ...
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Magnesium (Mg) is essential for animal health. Low Mg status (hypomagnesaemia) can be potentially fatal in ruminants, like cattle and sheep, and is widespread in Europe with economic impacts on farming. The application of Mg-rich agricultural lime products can help to ensure pasture forage consumed by animals contains sufficient Mg and, in areas of low pH, has the dual benefit of reducing soil acidity to levels best suited for grass production. This aim of this study was to determine if Mg-rich lime products could be used in a more effective manner in agricultural production systems. Potential resources of carbonate rocks (limestone, dolostone and chalk) in the UK, and their Mg:Ca status were identified, using datasets from the British Geological Survey (BGS). These data were combined with the locations of agricultural lime quarries, and areas where soils are likely to be deficient in Mg and/or require liming. Areas of potential demand for Mg-rich agricultural lime include areas in south east Wales, the Midlands and North East England. Although, areas where this may be an effective solution to low soil Mg values are restricted by the availability of suitable products. Conversely, areas of low soil pH in England and Wales are often found close to quarries with the ability to supply high Ca limes, suggesting that the low rates of lime use and liming is not due to supply factors. This study provides information that can help to guide on-farm decision making for use of Mg-rich and other lime resources. This could be used in conjunction with other options to reduce risks of Mg deficiency in livestock, and improve soil pH.
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In order to determine the effect of energy-mineral supplementation during the gestation-lactation transition period on the metabolic profile and reproductive indicators of Holstein cows,a total of 32 animals, between the third and fourth lactation, and body condition ≥ 3.5 were selected. The experiment was performed in Carchi province, Ecuador, during the rainy season. Two groups of 16 animals each were randomly formed. The same foods were supplied to all, and those in the treated group were supplemented with corn, in an amount of 1.0 kg DM, 30 days before parturition, and 2.0 kg DM at the beginning of lactation until 60 days postpartum, plus parenteral supplementation of 20 mL of kyrofosfan.The hematochemical parameters and reproductive indicators were determined, which were compared by t- Student test for independent samples. The contributions of Cu and Zn did not cover the requirements in both study groups. The metabolizable energy was deficient in the animals that were not supplemented with corn. In the cows from the treated group, the concentrations in blood serum of P, Cu, Zn and cholesterol, and the body condition were higher (P <0.05) at 30 and 60 days postpartum. Total proteins increased (P <0.05) at 60 days postpartum, while betehydroxybutyrate decreased (P <0.01) at 30 days postpartum.The supplementation decreased (P <0.05) the parturition-first service interval, the services per gestation (P <0.001) and the parturition-conception and parturition-parturition intervals. It is concluded that energy-mineral supplementation improves the metabolic profile and reproductive indicators.
Chapter
Milk is Nature's most nearly perfect food and for good reason. Colostrum the first secretion may contain as high as 24% solids and, provides immunoglobulins for the newborn to provide protection against disease until the immune system begins to produce antibodies against the microbial population in its environment. In 1850 average annual production per cow was 57 kg. The dramatic change was the commitment by the United States government beginning in 1862 with the creation of Land Grant Colleges and Universities. Their mission was teaching, research and, transfer of research findings to producers. Annual milk production per cow in 2019 was 10,500 kg, a 184-fold increase. In 2018, a cow in Wisconsin produced over 35,000 kg on milk in 365 days.
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Luis Rodrigo Balarezo-Urresta: https://orcid.org/0000-0001-5546-1259 Ernesto Noval-Artiles: https://orcid.org/0000-0001-6364-3546 Juan Ramón García-Díaz: https://orcid.org/0000-0002-2966-7824 In order to determine the effect of energy-mineral supplementation during the gestation-lactation transition period on the metabolic profile and reproductive indicators of Holstein cows,a total of 32 animals, between the third and fourth lactation, and body condition ≥ 3.5 were selected. The experiment was performed in Carchi province, Ecuador, during the rainy season. Two groups of 16 animals each were randomly formed. The same foods were supplied to all, and those in the treated group were supplemented with corn, in an amount of 1.0 kg DM, 30 days before parturition, and 2.0 kg DM at the beginning of lactation until 60 days postpartum, plus parenteral supplementation of 20 mL of kyrofosfan.The hematochemical parameters and reproductive indicators were determined, which were compared by t-Student test for independent samples. The contributions of Cu and Zn did not cover the requirements in both study groups. The metabolizable energy was deficient in the animals that were not supplemented with corn. In the cows from the treated group, the concentrations in blood serum of P, Cu, Zn and cholesterol, and the body condition were higher (P <0.05) at 30 and 60 days postpartum. Total proteins increased (P <0.05) at 60 days postpartum, while betehydroxybutyrate decreased (P <0.01) at 30 days postpartum.The supplementation decreased (P <0.05) the parturition-first service interval, the services per gestation (P <0.001) and the parturition-conception and parturition-parturition intervals. It is concluded that energy-mineral supplementation improves the metabolic profile and reproductive indicators. Para determinar el efecto de la suplementación energético-mineral durante el período de transición gestación-lactancia en el perfil metabólico y los indicadores reproductivos de vacas Holstein, se seleccionaron 32 animales, entre tercera y cuarta lactancia, y condición corporal ≥ 3,5. El experimento se desarrolló en la provincia Carchi, Ecuador, durante el período lluvioso. Se conformaron aleatoriamente dos grupos, de 16 animales cada uno. Se suministraron los mismos alimentos a todos, y a los del grupo tratado se les suplementó con maíz, en cantidad de 1.0 kg MS, 30 días antes del parto, y 2.0 kg MS al inicio de la lactancia hasta los 60 días posparto, más suplementación parenteral de 20 mL de kirofosfan. Se determinaron los parámetros hematoquímicos y los indicadores reproductivos, los que se compararon mediante prueba de t-Student para muestras independientes. Los aportes de Cu y Zn no cubrieron los requerimientos en ambos grupos de estudio. La energía metabolizable fue deficiente en los animales que no se suplementaron con maíz. En las vacas del grupo tratado, las concentraciones en suero sanguíneo de P, Cu, Zn y colesterol, y la condición corporal fueron superiores (P < 0.05) a los 30 y 60 días posparto. Las proteínas totales aumentaron (P < 0.05) a los 60 días posparto, mientras que el betehidroxibutirato disminuyó (P < 0.01) a los 30 días posparto. La suplementación disminuyó (P < 0.05) el intervalo parto-primer servicio, los servicios por gestación (P < 0,001) y los intervalos parto-concepción y parto-parto. Se concluye que la suplementación energético-mineral mejora los indicadores perfil metabólico y reproductivos. Palabras clave: energía, proteína, déficit, perfil metabólico, indicadores reproductivos In tropical regions, most grasses do not meet the mineral requirements of grazing dairy cows, so there are marked deficiencies that are associated with reproductive problems (McDowell and Arthington 2005 and García et al. 2010). In catlle herds, with an apparently adequate diet, alterations in protein, mineral and energy metabolism were diagnosed, with a manifest deterioration in reproductive capacity (García et al. 2011). In catlle herds of the Andean region from Ecuador, more than 30 % and 65 % of cows were diagnosed with high concentrations in blood serum of urea nitrogen En las regiones tropicales, la mayoría de los pastos no cubren los requerimientos minerales de las vacas lecheras en pastoreo, por lo que existen marcadas deficiencias que se asocian a problemas reproductivos (McDowell y Arthington 2005 y García et al. 2010). En rebaños bovinos, con una dieta aparentemente adecuada, se diagnosticaron alteraciones del metabolismo proteico, mineral y energético, con deterioro manifiesto en la capacidad reproductiva (García et al. 2011). En rebaños bovinos de la región andina de Ecuador, se diagnosticaron más del 30 % y 65 % de las vacas con elevadas concentraciones en suero sanguíneo de
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Polycultures, mixtures of different crop species in the same field, may provide both production and ecological benefits. Silage production in annual cropping systems may incorporate polycultures and take advantage of species’ niche partitioning, potentially stabilizing yield variation due to abiotic stress. Using maize (Zea mays L.) silage as the basis of our 3‐year study, we tested the impact on crop and soil attributes of replacing a fraction of maize with soy (Glycine max (L.) Merr.), sorghum (Sorghum bicolor var. bicolor × bicolor and var. sudanense [unnamed hybrid]), or a medley of soy, sorghum, and sunflower (Helianthus annuus L.). Compared to maize monocultures and on average for the three years, a replacement mixture of maize + soy lowered yields(1.57 vs. 1.87 kg m‐2), but increased the nitrogen (N), phosphorus (P), and potassium (K) concentration in the silage by 1.2x, 1.09x, and 1.03x, respectively. Maize + sorghum polycultures matched the biomass yields of maize monocultures (1.77 vs. 1.87 kg m‐2) and increased K concentration (10.2 vs. 8.2 g kg‐1). While random forest analysis revealed no change in post‐harvest soil mineral N with depth among treatments, there was a tendency for higher total mineral N left in the soil for soy‐containing vs. sorghum‐containing treatments (12.4 vs. 10.9 g m‐2). Silage polycultures are a feasible alternative to maize silage monocultures and can improve silage nutrient concentration with no yield penalty if maize or sorghum dominate plant stands. This article is protected by copyright. All rights reserved
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Calcium represented as calcium ion (Ca²⁺) belongs to the alkaline earth metal series in the periodic table. It is one of the most important ions for the living systems, owing to its role in many signal transduction processes in the higher eukaryotes. It has been found to be involved in both short-distance and long-distance signaling, with the signal transfer speeds reaching upto as high as 1400 μm s⁻¹. It is involved in the signaling within the cell by binding to the calmodulin protein, as well as also in the root-to-shoot signaling. Ca²⁺ involvement has also been observed in cold acclimation of plants, heat stress, pathogen attack, reactive oxygen species (ROS) response and respiratory burst in the cells. It is not the presence or absence of Ca²⁺ that bring about the changes in the plant metabolism and morphogenesis but the cytosolic concentration of the same represented by changes, which bring about changes in the plants. Besides being involved in all these responses, Ca²⁺ is also involved in the macronutrient deficiency stress. Macronutrient deficiency can either be caused by absence of the macronutrient in the soil or unavailability of the same. Macronutrient deficiency can be observed either in the lower leaves or upper leaves of the plants depending upon the mobility of the nutrient, which is further controlled by Ca signaling. In this review, we explore the involvement of Ca in nutrient mobilization from old leaves to new leaves, long-range signaling indicating the deficiency of nutrients in soil, and its involvement in metabolic and morphogenetic responses of plants to nutrient deficiency.
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Resolution of plant diversity goals with the agricultural demands placed on grasslands may result in conflict between farmers and conservationists. To investigate options for reconciling these important issues implementable in the short-term within agro-environmental schemes, we analysed the impact of four years’ management with grazing replaced by mowing on coordination of agricultural objectives, i.e. herbage yield, plant functional groups, nutrient contents and removal, forage value and plant diversity, i.e. species richness, Shannon-Wiener index, Ellenberg N indicator value. The study was carried out in three hillslope highland pasture sites (S1-S3) in the Šumava Mountains, Czech Republic, differing in soil properties and animal stocking rates, which were 0.92 in S1, 0.34 in S2, combined with mowing in some years and 0.73 in S3 LU ha-1. Some sections of each pasture site were twice yearly mowed. Our findings related to grazing combined or replaced with mowing were relevant to farmers’ priorities acceptable for dairy cattle nutrition. Across sites, the herbage dry matter yield, herbage P, K and Mg contents and removal, proportion of graminoids and Ellenberg N values decreased with mowing, but forage value and herbage Ca removal remained identical under both managements. Species richness, Shannon-Wiener index and herbage Ca content increased with mowing via spread of forbs and/or legumes. However, to achieve a merit, short-term grazing exclusion with mowing has to take into account site-specific soil nutrient conditions. Very high soil P availability prevented from the increase in species richness with mowing (S3). Contrarily, in sites with lower soil P availability, but different availability of other nutrients (S1, S2), mowing fostered number and/or proportions of forbs and/or legumes.
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The first issue of the Journal of Dairy Science in 1917 opened with the text of the speech by Raymond A. Pearson, president of the Iowa State College of Agriculture, at the dedication of the new dairy building at the University of Nebraska (J. Dairy Sci. 1:4–18, 1917). Fittingly, this was the birth of a new research facility and more importantly, the beginning of a new journal devoted to the sciences of milk production and manufacture of products from milk. Metabolic modifiers of dairy cow metabolism enhance, change, or interfere with normal metabolic processes in the ruminant digestive tract or alter postabsorption partitioning of nutrients among body tissues. Papers on metabolic modifiers became more frequent in the journal around 1950. Dairy farming changed radically between 1955 and 1965. Changes in housing and feeding moved more cows outside, and cows and heifers in all stages of lactation, including the dry period, were fed as a single group. Rations became wetter with the shift to corn silage as the major forage in many rations. Liberal grain feeding met the requirements of high-producing cows and increased production per cow but introduced new challenges; for example, managing and feeding cows as a group. These changes led to the introduction of new strategies that identified and expanded the use of metabolic modifiers. Research was directed at characterizing the new problems for the dairy cow created by group feeding. Metabolic modifiers went beyond feeding the cow and included environmental and housing factors and additives to reduce the incidence and severity of many new conditions and pathologies. New collaborations began among dairy cattle specialties that broadened our understanding of the workings of the cow. The Journal of Dairy Science then and now plays an enormously important role in dissemination of the findings of dairy scientists worldwide that address existing and new technologies.
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The aim of this study was to provide information about how calcium (Ca), magnesium (Mg) and potassium (K) respond to changes in the sugar concentrations and carbon isotopic compositions (δ13C) of Chinese prickly ash under field condition, therefore, to show why negative effect of Ca on Mg and K would be beneficial for adaptability of Chinese prickly ash grown on poor soils. Chinese prickly ash samples were collected in the six areas with different mean annual precipitation. Drought stress was evaluated via carbon isotope signatures. Additionally, concentrations of Mg, Ca, K and sugar concentrations in foliage, roots and soils were analyzed. Increased soil available Ca concentrations did significantly inhibit foliar Mg partitioning, implying that Ca did negatively affect Mg partitioning. Changes of foliar Mg concentrations were strongly controlled by variations of balance between soil available Ca and Mg. Thus, an accurate assessment of plant nutrient status should be useful for precision nutrient management in the fields. Magnesium deficiency did significantly induce foliar sugar accumulation, therefore, there were negative relationships between Mg concentrations and δ13C values in foliage. In addition, increased sugar concentrations did significantly increase δ13C values, implying that drought or water stress induced the accumulation of sugar in foliage. Linear and power function regression analysis revealed that negative effects of Ca on Mg and K should be responsible for accumulation of soluble sugar in foliage, which may enhance a plant’s adaptability on poor soils.
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El Magnesio, abundante en praderas pastoreadas por bovinos de leche, actúa como un cofactor en reacciones enzimáticas vitales para las principales vías metabólicas y presenta desaparición ruminal elevada (87%) aunque se desconoce su liberación en fuentes inorgánicas. Con el objetivo de evaluar su solubilización ruminal se incubaron cuatro fuentes inorgánicas (óxido de Mg (MgO), sulfato de Mg (MgSO4), cloruro de Mg (MgCl2) y carbonato de Mg (MgCO3)) determinando su desaparición de la materia seca (DMS) en 3 vacas Holstein (vacías, no lactantes) canuladas al rumen (620 ± 14 kg y 7 años) en el municipio de Santa Elena, Antioquia, Colombia (2538 msnm; bH – MB; 16ºc) consumiendo kikuyo (Cenchrus clandestinus (Hoechst Ex Chiov) Morrone) (Chemisquy et al 2010). Por triplicado se incubaron 0,5 g de cada fuente en bolsas de nailon con dos tamaños de poro (25 y 50μm), en el rumen de las vacas para evaluar DMS en tres tiempos (0, 12 y 24h). Se utilizó un diseño en bloques completos al azar con un arreglo factorial 2x3x4 (2 tamaños de poro, 3 tiempos de incubación y 4 fuentes minerales) y prueba de Tukey para significancia estadística de las diferencias. La incubación ruminal debe realizarse con tamaño de poro no superior a 50um, siendo MgCl2 y MgSO4 mas solubles en rumen, mientras que óxidos y carbonatos presentan solubilidad baja o nula dentro de las primeras 24 horas, lo cual puede dar luces para su utilización como suplemento mineral dentro de la dieta solida o agua de bebida del ganado lechero.
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Aim Magnesium (Mg) deficiency (known as grass tetany) is a serious metabolic disorder that affects grazing ruminants. We tested whether Mg-fertiliser can increase Mg concentration of Italian ryegrasses (Lolium multiflorum L.) including a cultivar (cv. Bb2067; ‘Magnet’), bred to accumulate larger concentrations of Mg. Methods Under controlled environment (CE) conditions, three cultivars (cv. Bb2067, cv. Bb2068, cv. RvP) were grown in low-nutrient compost at six fertiliser rates (0–1500 μM MgCl2.6H2O). Under field conditions, the three cultivars in the CE condition and cv. Alamo were grown at two sites, and four rates of MgSO4 fertiliser application rates (0–200 kg ha⁻¹ MgO). Multiple grass cuts were taken over two-years. Results Grass Mg concentration increased with increasing Mg-fertiliser application rates in all cultivars and conditions. Under field conditions, cv. Bb2067 had 11–73% greater grass Mg concentration and smaller forage tetany index (FTI) than other cultivars across the Mg-fertiliser application rates, sites and cuts. Grass dry matter (DM) yield of cv. Bb2067 was significantly (p < 0.05) smaller than cv. Alamo. The effect of Mg-fertiliser rate on DM yield was not significant (p ≥ 0.05). Conclusions Biofortification of grass with Mg through breeding and agronomy can improve the forage Mg concentration for grazing ruminants, even in high-growth spring grass conditions when hypomagnesaemia is most prevalent. Response to agronomic biofortification varied with cultivar, Mg-fertiliser rate, site and weather. The cost:benefit of these approaches and farmer acceptability, and the impact on cattle and sheep grazing on grasses biofortified with Mg requires further investigation.
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Objective: Minerals are one of the important nutrients for supporting the growth of sheep grazing in the highland, northeast of China. The experiment was conducted to investigate the relationship of both macro and micro minerals in sheep grazing in the highlands of six districts located in the Qilian Mountain of China. Methods: Samples of herbage (n=240) and soil (n=240) were collected at random in a "W" shape across the area designated for harvesting from 24 farms, where the sheep commonly graze in October (winter) for mineral analyses. In addition, serum samples were taken via jugular vein from 20 sheep per farm from 24 farms (n=480 samples in total) for serum minerals analyses. Mean values of macro and micro minerals were statistically compared among districts and the correlations among soil-plant-animal were statistically analyzed and correlations were regressed, as well. Results: The results revealed that there were variations for both macro and micro minerals among districts. Statistical analysis of the correlation coefficients between herbage and sheep were significantly different for most of the minerals but not for P, Cu, and Se. Many correlation regression coefficients were found significantly different among minerals of herbage, soil, and sheep serum especially those of K, Na, Fe, Mn, and Zn (between herbage and sheep serum), and Fe and Mn (between herbage and soil), Na, Fe, Mn, and Zn (between soil and sheep serum), respectively. The regression coefficient equations derived under this experiment for prediction of Ca (R2=0.618), K (R2=0.803), Mg (R2=0.767), Na (R2=0.670), Fe (R2=0.865), Zn (R2=0.950), Mn (R2=0.936), and Se (R2=0.630), resulted in significant R2 values. Conclusion: It is inferred that the winter herbage minerals in all the districts were below the recommended levels for macro minerals which indicated there would be some mineral deficiencies in sheep grazing the herbage in these regions. Supplemental minerals may therefore play an important role in balancing the minerals available from the herbage in winter and would lead to increased productivity in sheep on the highland areas of China. These findings could be potentially applied to the other regions for improving the livestock productivity.
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To date, no specific hormonal regulation system has been identified for homoeostatic control of the essential mineral Mg. In cattle, the maintenance of physiological plasma Mg concentration depends on gastrointestinal absorption, primarily from the rumen, which serves as a pool for covering the requirement. Whereas a possible surplus (absorption greater than requirement) is rapidly excreted by the kidneys, a shortage (absorption lower than requirement) cannot be compensated for by mobilization from the large Mg pool in bones or soft tissue, so that the maintenance of the necessary physiological Mg concentration in plasma relies on continuous and sufficient absorption. Our knowledge concerning the site and mechanisms of Mg absorption has improved during the last few decades, and meta‐analyses of the absorption of Mg in dairy cows have shown that the K content has a pronounced negative effect on Mg digestibility. The current recommendations of Mg intake propose a constant percentage of Mg and emphasize the depressive effect of high potassium (K) intake on Mg absorption. The current knowledge about the antagonism between K intake and Mg absorption allows a more flexible solution which includes the K content of the diet. An assessment of Mg intake is proposed that incorporates the improved knowledge of Mg absorption, metabolism and requirement. Within this framework, an equation is derived that allows a prediction of the amount of Mg required to compensate for dietary K content, the goal being to avoid both possible undernutrition or an unnecessary surplus of dietary Mg.
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Increasing use of animal manures in Saskatchewan requires information on the effect of manure addition on the availability of soil K, Ca and Mg and their concentrations in plant tissue. To address these issues, we examined the effects of repeated application of liquid swine and solid cattle manure at low and high rates on extractable K, Ca and Mg in soils from three different long-term field trials in Saskatchewan, and on plant K, Ca and Mg concentrations in cereal straw grown on the soils. After 5 to 7 yr of manure application, extractable potassium in the soils was significantly increased, while extractable Ca and Mg tended to remain similar, or was decreased with swine manure addition. In the cereal straw, concentrations of K, Ca, and Mg were all increased by repeated swine manure application, such that there was no significant increase in the K/(Ca + Mg) ratio. However, the K/(Ca + Mg) ratio in the cereal straw grown on soil amended with the high rate of cattle manure was increased. These findings suggest that increased risk of tetany potential from manure application would mainly be associated with excessive application rates of cattle manure in these soils, but should be monitored in feeds grown on all manured soils.
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Lime in pelletized form is potentially more convenient for farmers than ground limestone, as it can be applied using conventional fertilizer-spreading equipment. Pelletized lime is intended to maintain an optimum soil pH when applied annually at a rate of 350 kg lime/ha/yr. Interactions between lime and N fertilizer rate were examined by applying 0, 75, 150, 225 and 300 kg N/ha/yr (as calcium ammonium nitrate) in combination with 0, 175, 350 and 525 kg pelletized dolomitic lime/ha/yr over 3 yr to a permanent grassland sward used for silage production in County Down, Northern Ireland. Equal rates of ground lime, from the same source as the pelletized lime, were applied as a comparison. Effects on soil chemical properties, grass dry matter (DM) yield and herbage nutrient removal were examined. Lime maintained or slightly increased the soil pH, particularly in the top 2.5 cm of the profile, but there was no difference in the performance of pelletized lime compared to ground lime in any of the parameters measured. Lime had no significant effect on grass DM yield or grass quality; however, there was a significant (P < 0.05) reduction in yield at the first cut, particularly in year 2, when the highest lime rate (525 kg lime/ha/yr) was applied in the absence of N fertilizer. The dolomitic nature of the lime (11% Mg) resulted in significant (P < 0.001) increases in soil and herbage magnesium levels, and this could be beneficial for reducing the incidence of grass tetany in grazing animals. The P content of the herbage was also significantly higher in plots receiving lime, which suggests that lime may have enhanced the mineralization of P or stimulated root growth.
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The objective was to determine changes in the nutritional quality of the three predominant botanical components (i.e., grasses, legumes, forbs) in the Preveza Prefecture grasslands in North-Western Greece. The study involved collection of herbage samples during the bloom stage from 12 experimental plots located in three altitudinal zones (i.e., lower, middle, and upper) in 2 consecutive years. Samples were manually separated into the three botanical components and analyzed for crude protein (CP), neutral detergent fibre (aNDFom), acid detergent fibre (ADFom), lignin(sa), in vitro dry matter (DM) digestibility (IVDMD), in vitro NDF digestibility (IVNDFD), metabolizable energy (ME) and minerals (i.e., Ca, P, K, Mg). Altitudinal zone strongly affected the nutritive value of grasses, legumes and forbs. Indeed, altitude above sea level was positively correlated with CP, IVDMD and IVNDFD and negatively correlated with fibre contents. We found that the Ca:P ratio exceeded the animal functional disorder threshold, which posed a hazard; a belief amplified by the high K/(Ca+Mg) ratio, which would increase the risk of grass tetany in ruminants that primarily ate grasses in the upper zone.
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Secretion of saliva as well as absorptive and secretory processes across forestomach epithelia ensures an optimal environment for microbial digestion in the forestomachs. Daily salivary secretion of sodium (Na+) exceeds the amount found in plasma by a factor of 2 to 3, while the secretion of bicarbonate (HCO3-) is 6 to 8 times higher than the amount of HCO3- in the total extracellular space. This implies a need for efficient absorptive mechanisms across forestomach epithelia to allow for an early recycling. While Na+ is absorbed from all forestomachs via Na+/H+ exchange and a non-selective cation channel that shows increased conductance at low concentrations of Mg2+, Ca2+ or H+ in the luminal microclima and at low intracellular Mg2+, HCO3- is secreted by the rumen for the buffering of ingesta but absorbed by the omasum to prevent liberation of CO2 in the abomasum. Fermentation provides short chain fatty acids and ammonia (NH3) that have to be absorbed both to meet nutrient requirements and maintain ruminal homeostasis of pH and osmolarity. The rumen is an important location for the absorption of essential minerals such as Mg2+ from the diet. Other ions can be absorbed, if delivered in sufficient amounts (Ca2+, Pi, K+, Cl- and NH4+). Although the presence of transport mechanisms for these electrolytes has been described earlier, our knowledge about their nature, regulation and crosstalk has increased greatly in the last years. New transport pathways have recently been added to our picture of epithelial transport across rumen and omasum, including an apical non-selective cation conductance, a basolateral anion conductance, an apical H+-ATPase, differently expressed anion exchangers and monocarboxylate transporters.
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The prevalence of subclinical hypocalcemia in the transition cow is unknown. Cows with subclinical hypocalcemia have no clinical signs of hypocalcemia but may be more susceptible to other diseases. The objective of this study was to determine the prevalence of subclinical hypocalcemia in the US dairy herds. As a part of the United States Department of Agriculture's National Animal Health Monitoring System 2002 Dairy study, serum samples were collected from 1462 cows within 48 h of parturition. The samples were sorted by lactation number: 1st (n=454), 2nd (n=447), 3rd (n=291), 4th (n=166), 5th (n=72), and 6th (n=32). Subclinical hypocalcemia (<2.0 mM) increased with age and was present in 25%, 41%, 49%, 51%, 54%, and 42% of 1st-6th lactation cows, respectively. Cows with serum calcium concentrations >2.0 mM had significantly lower serum non-esterified fatty acids indicating better energy balance than those with subclinical hypocalcemia. Subclinical hypocalcemia may make cows more susceptible to secondary diseases but more research will be required to determine if this is true.
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Rumen and caecal digesta were collected, under anaesthetic, from eight sheep offered either hay, pelleted concentrate or pasture at the Johnston Memorial Laboratory, Lincoln University during 1991. Subsamples of digesta were incubated at 39°C for 1 h after adjustment of pH within the range 0.5-12 by the addition of H₂S0₄ or NaOH. The samples were centrifuged at 30 000 g for 30 min and magnesium (Mg) concentration measured in the 30 000 g supernatant fraction and in total digesta to assess Mg solubility. In rumen digesta Mg solubility declined from 0.86 at pH 5 to 0.30 at pH 7 and differences in response between diets were small. Magnesium solubility in caecal digesta was generally higher than in ruminal digesta, and particularly at pH values > 6. At pH 7 the difference was twofold. Moreover, differences were observed between diets in the rate of decline in solubility in caecal digesta with increasing pH. At pH 5, 0.90 of Mg from hay and concentrate diets was soluble compared with only 0.8 for pasture. At pH 7 Mg solubility in caecal digesta from hay and concentrate fed animals was almost double that from pasture fed animals (0.64 and 0.62 v. 0.36, respectively). The implications of the findings for Mg homoeostasis in ruminants are discussed.
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Chapter
Magnesium has been recognized as an essential dietary element for about 70 years, and the element's role in hypomagnesemic tetany, also known as grass tetany, has been known since the early 1930s. The solubility of magnesium compounds in various solutions has been used by several researchers to predict bioavailability of supplemental sources. The solubility of magnesium from forages has been examined by feeding ruminally fistulated animals various forages and collecting ruminal fluid for magnesium analysis or by measuring the disappearance of magnesium from forages incubated in dacron bags in the rumen. Generally, urinary magnesium concentrations are considered to provide more accurate information than serum magnesium concerning the element's status in animals. Several factors have been found that influence the absorption and, consequently, bioavailability, of magnesium. It is generally accepted that absorption of magnesium from the intestinal tract and tubular reabsorption of magnesium in the kidney are lower in older animals than in younger animals. Availability of magnesium from tall fescue and fescue-red clover herbage was greater in mature wethers than dry cows, with weaned calves being intermediate. Standard magnesium sources used in comparative assay studies have generally been either magnesium sulfate or magnesium oxide with some use of magnesium phosphate. Magnesium sulfate is a highly soluble, uniform product and is considered the standard choice. Magnesium oxides, especially feed grade products, are considerably more variable in parent material, processing, solubility, and in their absorption by animals. Only limited testing has been conducted with magnesium phosphate.
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Pastures from 27 sites (19 farms), mainly in the Hawke's Bay district, were sampled during an outbreak of grass tetany in beef breeding cows. Pastures were generally ryegrass-dominant, with little clover at grazing height, and were mainly closely grazed. Chemical analyses gave the following results (mean value and range of values. %) :-Mg, 0.19 (0.14–0.25): Ca, 0.39 (0.29–0.61); K. 3.29 (2.0–4.0); Na. 0.06 (0.00–0.19); P, 0.50 (0.35–0.69); N. 5.28 (4.2–6.3); non-protein N. 0.94 (0.75–1.17); non-protein N as a percentage of total N, 18 (16–22); soluble carbohydrate. 9.7 (3.8–15.5); ratio K/(Ca + Mg). 2.45 (1.42–3.63).The magnesium levels fall within the range where occurrence of hypomagnesaemic tetany may be considered a possibility, and the over-all results suggest that the deficiency of magnesium in the animal is induced by a high-protein—low-energy intake. Possible contributory factors in the pasture are high potassium, low calcium, and low sodium. Since no fertiliser nitrogen or potassium was used, the high level of these elements is attributed mainly to luxury consumption from high-fertility patches resulting from the return of animal excreta.
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This study was undertaken with the objective of providing more basic information on the absorption and excretion of calcium (Ca) and magnesium (Mg) by lactating cows when high levels of potassium (K) are fed. Employing potassium carbonate as the source of supplemental K, total mixed rations were formulated to contain 1.6 (low), 3.1 (medium) and 4.6% (high) K. The three rations were fed to 15 Holstein cows in mid-lactation in a 3 × 3 Latin square experiment replicated five times. The experimental periods were 21 d in length. Blood, rumen and milk samples were obtained during the 2nd and 3rd wk of each experimental period and two cows from each treatment group were subjected to total collection procedures for feces and urine during the last 4 d of each experimental period. Dry matter intake was 23.0, 23.8 and 22.3 kg d⁻¹ for the cows fed the low, medium and high K diets, respectively. Milk yield was lower (P < 0.05) for cows fed the high compared to the low and medium K diets. Level of K in the diet did not influence the fat and protein content of the milk but Ca content was lower (P < 0.05) for cows fed the medium and high K diets compared with those fed the low K diet. Plasma K levels were 15.0, 15.7 and 16.2 mg dL⁻¹ while plasma Mg levels were 2.35a, 2.25ab and 2.17b mg dL⁻¹ for cows on the low, medium and high K diets, respectively. The acetate to propionate ratio in the rumen fluid was wider (P < 0.05) for the cows fed the medium and high K diets compared with those fed the low K diet. The apparent absorption of Mg but not Ca was reduced with increasing levels of K in the diet. Both water consumption and urine output were greater (P < 0.05) for the cows fed the medium and high K diet compared with those fed the low K diet. The concentration of Ca and Mg in the urine dropped markedly and total excretion of Ca and Mg was lower (P < 0.05) for cows fed the medium and high K diets compared with those fed the low K diet. It was concluded from the results of this study that high K levels in the diet interfere with absorption of Mg but not Ca. However, K did appear to interfere with the utilization of Ca as indicated by the lower amount of Ca in the milk and urine. Increasing K levels in the diet increased water consumption and urine output which has major implications for waste management. Key words: Lactating cows, excess potassium, calcium, magnesium
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Apparent magnesium (Mg) absorption was measured in mature sheep fed hay or vegetative grass, each with and without supplemental glucose (water-soluble carbohydrate). Glucose supplemented in varying levels to hay increased apparent Mg absorption (linear, P less than 0.01) and urinary-Mg output (linear, P less than 0.01). Glucose added to vegetative grass did not change Mg absorption, but plasma-Mg concentrations were higher (P less than 0.05) than controls. Absorption and urinary loss of Mg were positively correlated (P less than 0.01) when hay or grass was fed, with or without glucose. Varying dietary glucose levels in hay or grass did not influence (P greater than 0.05) apparent absorption of calcium (Ca), potassium (K), or phosphorus (P). This study suggests that supplementation with a readily available carbohydrate during periods of dietary Mg deficiency may reduce the rate of plasma-Mg decline characteristic of ruminants grazing spring grass.
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Der Einfluß einer hohen Phosphoraufnahme auf die scheinbare Magnesiumabsorption bei trächtigen Färsen Der Einfluß der Phosphorversorgungshöhe auf die scheinbare Magnesiumabsorption wurde in einem 31 × 30 Tage dauernden cross-over-Versuch an 6 Färsen nach Verfütterung von Rationen mit 5,4 g Magnesium/kg TS und 2,2 oder 6,4 g Phosphor/kg TS untersucht. Die P-Ergänzung erfolgte über Na2HPO4. Der Na-Gehalt wurde in den P-armen Rationen durch NaHCO3 ausgeglichen. Nach der Fütterung der P-reichen Ration sank die Ausscheidung von Mg über den Harn signifikant von 10,3 auf 8,8 g pro Tag, wobei sich die scheinbare Mg-Absorption signifikant von 29,9 auf 24,5% erniedrigte. Der höhere P-Gehalt hatte keinen Einfluß auf die Ca-Exkretion. Der Mg-Gehalt in der Ration und die P-Konzentration bei der P-reichen Ration lagen höher bzw. die P-Konzentration bei der P-armen Ration lag niedriger als in praxisüblichen Rationen. Diese unüblichen Mg- und P-Gehalte der Rationen und der verhältnismäßig geringe Effekt der P-Aufnahme auf die scheinbare Mg-Absorption scheinen die Relevanz der Ergebnisse einzuengen. Trotzdem wird das Risiko aufgezeigt, das auftreten kann, wenn hohe P-Aufnahmen bei gleichzeitiger niedriger Mg-Aufnahme eine Mangelversorgung an Mg verstärken können.
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SUMMARY Mineral balance trials with lambs fed peren- nial ryegrass, smooth bromegrass, orchardgrass and tall fescue herbage at two growth stages in 2 years showed significant effects of date of cutting and grass species on the concentration, apparent absorption (AA) and retention of major elements. Concentrations of calcium, phosphorus, potassium and sulfur declined with maturity, with little change in magnesium. Mean AA values for calcium, phosphorus, mag- nesium, potassium and sulfur were 29.4, 10.4, 36.6, 89.2 and 64.7%, respectively. Apparent absorption of calcium, phosphorus, potassium and sulfur declined with maturation of the herbage, while magnesium availability in- creased. Species differences in AA and reten- tion of minerals were noted, although between- animal variability was high. Lambs on tall fescue utilized calcium, phosphorus, and mag- nesium less efficiently, although concentrations of these elements in rescue were as high or higher than in the other species. Calculations of requirements indicated that concentrations of calcium, phosphorus and magnesium in herbage may have been inadequate for maximum growth of early weaned lambs. Seasonal changes in the in vitro dry matter digestibility (IVDMD) and chemical composi- tion of grazed pastures were determined, and Published with the approval of the West Virginia Agricultural Experiment Station as Scientific Paper No. 1507. 2The authors acknowledge the assistance of Ms. Patricia Lancaster in analysis of material from metabo- lism trials, and wish to thank Dr. W. V. Thayne for statistical advice. a Present address: Purdue University, Lafayette, IN. *Divisions of Animal and Veterinary Science, and relationships between chemical composition, mineral utilization and in vivo DMD and intake were examined by multiple regression analysis. Lignin was found to be the most important component affecting IVDMD. When measures of mineral concentration and availability were included in regressions of composition on nutri- tive quality of the grasses, they were found to improve significantly the proportion of variabil- ity in DMD and intake accounted for by structural organic fractions of the herbage.
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In surgically modified sheep fed perennial ryegrass, most K was associated with the water-soluble fraction of the diet, digesta, and faeces, and much Mg, Ca, and P was associated with both the water-soluble and dilute-alkali-insoluble fractions of the diet, rumen digesta, ileal digesta, and faeces. Changes in pH of the digesta markedly influenced the distribution of Mg, Ca, and P between fractions. The proportion of Mg, Ca, and P associated with the dilute-alkali-insoluble fraction increased and that with the water-soluble fraction decreased as the digesta moved along the small and large intestine. In in vitro studies, increasing the pH and the concentrations of Ca and K decreased the binding of Mg to the dilute-alkali-insoluble fraction from the diet, digesta, and faeces.
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Summary Effects of increasing the level of dietary Mg by kieserite (MgSO4"H20) fertilization and direct addition of Epsom salts (MgSO~. 7H 2 O) to the drinking water were determined using sheep fed timothy (Phleum pratense L.) hays grown on low Mg soils in Northern West Vir- ginia. Replicated stands containing timothy as the predominant species, with and without kieserite fertilization at the rate of 2.2 t/ha (390 kg Mg/ha), were harvested at the flowering stage. Preharvest sampling of timothy plants at several growth stages indicated that fertilization increased (P
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Magnesium oxides were unground prills sieved to between 30 and 100 screen mesh size (30–100), or 12 and 40 mesh (12–40), or forms ground from the 12–40 to pass a 200 mesh (−200) or a 20 mesh (−20) screen. In the first experiment, magnesium recoveries, the increase in urinary excretion of magnesium above baseline for 2 days following oral administration of 100 g of magnesium oxide to cattle, were 0, 0, 10.2%, and 6.29% for the respective screen sizes. Recovery from 12–40 increased to 4.47% following a series of four daily 100-g oral loads. These amounts represent the relative availability of magnesium and magnesium oxide forms examined, not the absolute availability of magnesium from any one form.
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The main objective of this study was to compare potassium (K), calcium (Ca), and magnesium (Mg) utilization and grass tetany potential of orchardgrass (Dactylis glomerata L.) and tall fescue (Festuca arundinaceae Schreb.) fertilized with dairy manure or commercial fertilizer. The study was conducted from 1994 through 2000 in Willsboro, NY on a Kingsbury clay soil (very-fine, illitic, mesic Aeric Ochraqualf) of somewhat poor drainage. The design was a split-plot in a randomized complete block with two manure rates (16.8 Mg ha and 33.6 Mg ha) and one fertilizer treatment (84 kg N ha at spring greenup and 56 kg N ha prior each regrowth harvest) as the main plots and grass species as subplots replicated six times. Potassium concentration and uptake increased after two years of manure application compared to commercial fertilizer treatment and residual effects of manure were large at least three years following manure application. Calcium concentration and uptake decreased after two years of manure application compared to the commercial fertilizer treatment, but there were no differences in treatments three years after manure application had ceased. Magnesium concentration and uptake at the high manure rate did not differ from fertilizer treatment in all years. Orchardgrass was more grass tetany prone than tall fescue as a result of dairy manure application. The K/(Ca+Mg) ratio in plant tissue was as high as 3.26 for orchardgrass and as high as 2.11 for tall fescue for spring harvests at the highest manure rate. The K/(Ca+Mg) ratio in plant tissue was in the range of 0.34–1.74 (below the 2.20 critical level) for all three years with no manure application. Soil K increased in manure treatments from an initial 76.8 kg ha (1993) to 171.7 kg ha (1997) in the highest manure treatment. After three years of no manure applications, soil K had been reduced to the initial level.
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Two feeding trials were carried out with lactating cows during early spring (September) and late spring (November). Three groups of animals were used; one received a starch supplement at each milking, the second a peanut oil supplement at each milking, and the third (control) received no supplement. Feed during the experimental periods was ‘Grasslands Ruanui’ perennial ryegrass, with a mineral composition believed to be conducive to hypomagnesaemic tetany.In the first trial plasma magnesium levels of mature animals were markedly lowered on all treatments by feeding Ruanui ryegrass; the effect on young animals was much smaller. No cases of clinical tetany were observed. Depression of plasma magnesium levels was lessened by starch supplementation and increased by oil supplementation. Plasma magnesium and phosphorus levels were positively correlated for individual cow means over the experimental period. Plasma calcium levels lay in the normal physiological range throughout Faecal levels of higher fatty acids and fatty acid soaps closely correlated with depression of plasma magnesium levels in mature cows, but were less closely correlated in younger animals. Pasture levels of trans-aconitic and citric acids were in the normal range and were considered unimportant.In the second trial the effects of Ruanui ryegrass feeding and of the other treatments were consistent with the results in the first trial, but the differences were much smaller.
Article
1. An artificial diet low in magnesium (0·01–0·02% of the dry matter), and providing about 0·5 g. magnesium daily, was prepared from paper pulp, maize gluten, magnesium-free minerals and vitamins A and D and used in experimental studies with two non-lactating cows. 2. The omission of a dietary supplement of magnesium oxide (5 g./day) caused a rapid fall in the excretion of magnesium in the urine, from values of 1–2 g./day to virtually zero within about 4 days. There was a similar rapid fall in the concentration of magnesium in the serum, from about 2·7 to 2·0 mg./lOO ml., and then a slow fall to between 1·0 and 1·5 mg./lOO ml. after 12 days. Faecal excretion of magnesium was also reduced but the faecal loss continued at about 1·0 g./day after 2–3 days on the low magnesium diet. 3. The availability of the magnesium of various salts was determined by giving them as supplements to the basal diet and measuring the increase in the excretion of magnesium in the urine. The mean value was 26·2% in one cow and 34·5% in the other, a highly significant difference ( P < 0·01). The availabilities of the oxide, nitrate, acetate and lactate were similar, but the citrate gave a higher value and the sulphate, silicate and, in one cow, the chloride a lower value.
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Three sheep, equipped with cannulae in the dorsal rumen sac, abomasum and ileum, were fed a low sodium diet of artifically dried young grass. Mean daily intake of sodium was 310 mg. The sheep were given daily supplements of 0 or 2·3 g sodium by an intraruminal infusion. The concentration of K in mixed saliva and ruminal fluid from the sheep not given sodium supplements increased and the concentration of Na decreased markedly. The changes in the ion concentrations were associated with an increase of the transmural potential difference across the ruminal epithelium. The altered ion concentrations of Na and K in the ruminal fluid and the increased potential difference were accompanied by a decrease in Mg absorption from the forestomachs. The apparent availability of Mg from the gastrointestinal tract decreased from 34·5 (sodium supplementation) to 22·3 (low sodium intake). It is suggested that a daily intake of Na of 310 mg did not cover the sodium requirement of these sheep and that a low sodium intake influences the absorption of Mg in a similar manner as it has been observed with a high K intake. The results are discussed in context of grass tetany in ruminants. It is suggested that an inadequate intake of sodium is an overlooked factor of the pathogenesis of this disease.
Article
1. In each of three experiments, two sheep were given diets consisting of hay, or two parts hay to one part barley or one part hay to two parts barley. Each sheep was equipped with a cannula into the rumen and re-entrant cannulas into the proximal duodenum and the terminal ileum. The rations containing barley were supplemented to adjust the intake of calcium, phosphorus, magnesium, sodium and potassium to a level similar to that in the all-hay ration. Paper impregnated with chromic oxide (Cr 2 O 3 ) was given twice daily by rumen fistula. 2. Amounts of crude ash and the five minerals entering and leaving the small intestine and excreted in the faeces were measured. The amounts passing through the re-entrant cannulas were adjusted to give 100% recovery of chromic oxide. The values were used to calculate the direction and net movements of the elements through the walls of the three main parts of the alimentary tract. 3. In all instances there was an extensive net secretion of Na and P between mouth and small intestine, net absorption of K and P from the small intestine and of Na from the large intestine. 4. The net movements of Ca and Mg were small and rather variable. In five of the six observations there was a small net secretion of Ca and small net absorption of Mg during passage of the digesta through the reticulo-rurnen, omasurn and abomasurn. Net secretion of Ca and Mg apparently occurred in the small intestine and net absorption of Mg in the large intestine. 5. The only between-diet differences were small differences in net movements of Na and K.
Article
1. Three experiments are reported in which magnesium metabolism trials were carried out with milking cows that had been changed abruptly from typical winter rations to herbage cut freshly from swards at an early or at a more mature stage of growth and fed in the stall. 2. The intake of herbage magnesium by individual animals varied from 9·5 to 15·2 g./day. Much of this variation was, however, associated more with differences in the palatability and dry-matter content of the herbage offered than with individual differences in appetite. 3. The mean proportion of the ingested herbage magnesium excreted in the faeces was similar in all three experiments, being 82·3, 83·0 and 82·4% respectively. With any given sward there were, however, wide variations between individual animals in their utilization of herbage magnesium. 4. The supply of ‘available’ magnesium to animals fed cut herbage in the stall varied from 0·5 to 4·2 g./day, as compared with values of from 2·6 to 10·5 g./day obtained previously (Rook et al. 1958) with cattle fed typical winter rations. In spite of this lower intake of ‘available’ magnesium, the animals maintained a positive magnesium balance.
Article
Der Stärkeabbau aus verschiedenen Stärkearten nach Inkubation mit Pansensaft oder bakterieller α-Amylase Untersuchungen über den Stärkeabbau aus La Plata Mais, Rispenhirse, Sorghumhirse, Kanariensaat, Weizen, Maisflocken, Puffmais, Paselli, Mais, Maisstärke und Gerste wurden nach Inkubation mit Pansensaft (Exp. A) oder mit α-Amylase bakterieller Herkunft (Exp. B) durchgeführt. Als Spendertiere dienten Kühe, die mit Heu guter Qualität (Exp. A 1; “Heu-Kuh”) oder mit 8 kg Heu und 10 kg Kraftfutter (Exp. A2; “Kraftfutter-Kuh” gefüttert wurden. Die Inkubation mit bakterieller α-Amylase wurde mit Konzentrationen von 0,01, 0,1, 1 und 10 mg bakterieller α-Amylase (4500 SU/mg Calbiochem, San Diego, USA) in Experiment B1 und in den Experimenten B2 und B3 mit 10 mg durchgeführt. Der Stärkeabbau nach Inkubation mit Pansensaft der Kraftfutter-Kuh war erheblich größer als der nach Inkubation mit Pansensaft der Heu-Kuh. Relativ war die Zunahme bei den schwer abbaubaren Stärkequellen am größten. Obwohl die Korrelation zwischen dem Stärkeabbau nach Inkubation mit α-Amylase und Inkubation mit Pansensaft von Heu- und Kraftfutter-Kuh hoch war (jeweils 0,96 und 0,93) wurden große Differenzen zwischen Stärkeabbau durch α-Amylase und Pansensaft ermittelt. Keine Unterschiede wurden für die α-Amylase-Aktivität zwischen pH 5,0 und 6,5 beobachtet. Die eingesetzte Menge an α-Amylase zeigte einen großen Einfluß auf den Stärkeabbau. Die vorliegenden Untersuchungen zeigen, daß sowohl Stärkeart als auch die Aufschlußmethode den Stärkeabbau beeinflussen. Die Amylase-Aktivität im Pansensaft wurde durch die Fütterung der Spendertiere beeinflußt. Es wird vermutet, daß am Stärkeabbau im Pansen nicht nur α-Amylase sondern auch andere bakterielle Enzyme beteiligt sind.
Article
Vergleich des Abbaues von Stärke in Kraftfutter durch Enzyme und Pansensaft Der Abbau von Stärke, verschiedener stärkehaltiger Futtermittel wurde untersucht mit α-Amylase, Pankreatin, Amyloglucosidase und Pansensaft. Der Grad des Stärkeabbaues nach 4 Stunden Inkubation mit amylolytischen Enzymen variierte stark zwischen den 21 untersuchten stärkehaltigen Futtermitteln. Die Unterschiede im Grad des Stärkeabbaues zwischen den Stärkearten waren unterschiedlich nach Inkubation mit α-Amylase und Amyloglucosidase. Auch bei 6 Stunden in vitro Inkubation mit Pansensaft von einer mit Heu gefütterten Kuh und einer mit Kraftfutter gefütterten Kuh war der Grad des Stärkeabbaus der 21 Stärkearten stark unterschiedlich. Der Abbau von Stärke war signifikant höher nach Inkubation mit Pansensaft von einer Kraftfutter-Kuh als mit Pansensaft von einer Heu-Kuh. Aufgeschlossene Stärkearten zeigten einen höheren Stärkeabbau als nicht-aufgeschlossene Stärkearten, sowohl nach dem Abbau mit Enzymen als auch mit Pansensaft. Nicht-amylolytische Enzyme, wie z.B. Cellulase, Lipase und Protease, konnten den Abbau von Stärke durch Amyloglucosidase nicht erhöhen. Die Untersuchungen zeigten daß es Unterschiede gibt in der Reihenfolge und dem Grad des Stärkeabbaus zwischen Abbau durch Enzyme und Pansensaft. Der Abbau der Stärke durch Pansensaft in vitro, kann deshalb mit Hilfe des Abbaus durch Enzyme, nur grob vorhergesagt werden.