Sergio Calsamiglia

• Autonomous University of Barcelona

The objective of this network meta-analysis was to determine the efficacy of different mycotoxin binders (MTB) to reduce aflatoxin M1 (AFM1) in milk. A literature search was conducted to identify in vivo research papers from different databases. Inclusion criteria were in vivo, dairy cows, description of the MTB used, doses of MTB, aflatoxin inclus...

A network meta-analysis was conducted to determine the effects of feeding feed-grade urea (FGU) or slow-release urea (SRU) as a replacement for true protein supplements (control; CTR) in high-producing dairy cattle diets. Research papers were selected (n = 44) from experiments published between 1971 and 2021 based on the following criteria: dairy b...

Eight dual-flow continuous culture fermenters were used in three periods to study the effects of diets containing heat-treated soyabean meal (HSBM) or corn gluten meal (CGM) on ruminal microbial fermentation and the degradation of individual amino acids (AA). Treatments were a mix of non-protein nitrogen (N; urea and tryptone) that were progressive...

The objective of this study was to determine the effect of the mycotoxin binder montmorillonite (MMT) supplemented in the diet of dairy cows on the bioavailability of vitamins A, D, E, B1 and B6. Six multiparous Holstein-Friesian cows were used in a crossover design with two periods. Treatments were a control diet with or without MMT. Vitamins were...

Context Soybean meal (SBM) is the most important protein source used to feed dairy cows, and methods have been developed to increase its nutritional value by protecting the proteins against rumen degradation. Protection of solvent-extracted SBM with saturated fats can achieve this, but effects on lactation performance and nutrient digestibility hav...

Caja, G., A. Elhadi, M. Rodriguez-Prado, A. Belaid, X. Such, L. Bahloul, and S. Calsamiglia. 2021. Impact of dietary protein content and methionine supplementation in dairy ewes in early lactation. Page 323 in Proc. 72nd Annual Meeting EAAP. Book of abstracts No. 27. Davos, CH. https://doi.org/10.3920/978-90-8686-918-3.

Simple Summary Mycotoxins are frequently found in animal feeds. Mycotoxicosis are often subclinical and difficult to diagnose, but result in important production losses. Mycotoxin binders are used to reduce their impact on health and performance. However, the unspecific mechanism of adsorption may also bind other essential nutrients, including vita...

Caja, G., A. Elhadi, M. Rodríguez-Prado, A. Belaid, X. Such, L. Bahloul, and S. Calsamiglia. 2021. Efectos del nivel de proteína bruta y de la suplementación con metionina protegida a inicio de lactación en ovejas lecheras. p90 in Proc. XIX Jornadas de Producción Animal of AIDA, Zaragoza, Spain. https://www.aida-itea.org/aida-itea/files/jornadas/20...

In the last 20 years there has been extensive in vitro research on the effects of plant extracts and essential oils on rumen microbial fermentation. The main objectives have been to improve energy metabolism through a reduction in methane emissions and an increase in propionate production; and to improve protein metabolism by reducing proteolysis a...

Simple Summary Despite the high number of products based on essential oils (EO) mixtures as feed additives for dairy cattle on the market, few studies have been specifically designed to explore possible additive, synergistic or antagonistic effects. This study aims to explore additive, synergistic, or antagonistic effects of EO mixtures to improve...

The objective of this study was to evaluate the relative bioavailability of two 2-hydroxy-4-(methylthio)butanoic isopropyl esters (HMBi) obtained through different production processes and an encapsulated rumen-protected Met using the area under the curve (AUC) method. The new HMBi product (Kessent MF Liquid, Kemin Animal Nutrition and Health) was...

The objective of this study was to identify changes in prepartum behavior associated with the incidence of postpartum diseases in dairy cows. Multiparous Holstein cows (n = 489) were monitored with accelerometers for 3 wk prepartum. Accelerometers measured steps, time at the feed bunk, frequency of meals, lying bouts, and lying time. Postpartum hea...

Simple Summary Livestock production has been identified as an important source of greenhouse gas emissions. The current study was conducted to quantify the carbon footprint of Spanish dairy farms and to evaluate the potential of nutritional and management practices for mitigating methane emissions at farm level. The carbon footprint ranged from 0.6...

Simple Summary Essential oils and their active compounds have been investigated as feed additives to improve performance in a wide range of farm animals. Most studies related to ruminants have been conducted in vitro and suggest that their effects may be beneficial for ruminant health and production performance. However, in vivo studies are limited...

Current feeding systems are based on the assumption that the AA profile of rumen undegraded protein is similar to that of the original feed. The objective of this experiment was to determine rumen bacterial degradation of individual essential AA in fish meal (FM) and blood meal (BM). Eight dual-flow continuous-culture fermentors were used in a comp...

The objective of this study was to evaluate the capacity of 6 mycotoxin binders (MTB) to adsorb 3 AA and 4 water-soluble vitamins (WSV). Two experiments were conducted in in vitro conditions to simulate postruminal digestion with pepsin, malic acid, citric acid, acetic acid, and lactic acid at pH 3.0 and intestinal digestion with bile salts and pan...

Simple Summary Essential oils (EO) can be used as natural alternatives to in-feed antibiotics. Most EO products in the market are based on a combination of EO or their active molecules but prove of additivity or synergy is lacking. The effect of six EO (tea tree oil—TeTr, oregano oil—Ore, clove bud oil—Clo, thyme oil—Thy, rosemary oil—Ros and sage...

The objective of this project was to develop and test a web-based virtual dairy herd to help students understand the structure and functioning of a dairy herd, and to promote active learning. At the beginning of the course, the instructor defines the profiles of herds to be assigned to students (e.g., herd size, production, diets, fertility). Each...

Three doses (5, 15 and 30 mg/l in experiment 1; and 100, 250 and 500 mg/d in experiment 2) and three proportions of anise oil (A) and capsicum oleoresin (C; 1A:3C, 2A:2C and 3A:1C) were used to evaluate their effects on rumen microbial fermentation. In experiment 1, a completely randomized block in vitro batch fermentations were conducted in tripli...

Simple Summary In large intensive beef production systems, the identification of sick animals is difficult. We hypothesized that sick bulls would change daily activities when sick. Thus, the use of activity monitoring devices might allow for the early identification of sick bulls. The device used measured steps counts, lying time, lying bouts, and...

The objective of this study was to analyze whether changes in behavior can be a good early predictor of sickness in calves. Friesian males calves (n = 325; 30 ± 9 d of age; 65 ± 15 kg) were monitored with an activity-monitoring device from 30 to 90 d of life in 4 periods corresponding to 4 seasons. The activity-monitoring device measured number of...

There are heightened concerns globally on emerging drug-resistant superbugs and the lack of new antibiotics for treating human and animal diseases. For the agricultural industry, there is an urgent need to develop strategies to replace antibiotics for food-producing animals, especially poultry and livestock. The 2nd International Symposium on Alter...

Live yeast additives may help optimize ruminal fermentation of high‐grain diets, especially when the starch of the ration is highly fermentable. Eight dual flow continuous culture fermenters were used in a 2 × 2 factorial design in two replicated periods of 9 days (six for adaptation and three for sampling) to determine the effect of live yeast and...

Because high quality forages are scarce and expensive, most Mediterranean countries traditionally follow a “barley-beef” system. Within a few weeks after switching to a dry feed diet, the progressively weaned calf is able to digest its diet as efficiently as adult ruminants (Anderson, 1987; Lalles and Poncet, 1990). Assuming that in high concentrat...

The management of a dairy farm involves taking difficult technical and economic decisions such as the replacement of some cows to either maintain or increase the productivity of the farm. However, there is not a standard method supporting the selection procedure of which animals need to be culled. In the present study we used decision trees to deve...

Dairy farms need to improve their competitiveness through decisions that are often difficult to evaluate because they are highly dependent on many economic and technical factors. The objective of this project was to develop a stochastic and dynamic mathematical model to simulate the functioning of a dairy farm to evaluate the effect of changes in t...

The supply of high-concentrate diets results in the reduction in ruminal pH and the development of acidosis. Because the reduction of pH occurs at the same time as the diet is changed, the effects are confounded. For example, high-concentrate diets ferment towards propionate, and low rumen pH also results in greater propionate production. Which fac...

Manchega (MN) and Lacaune (LC) are two semi-coarse-wooled dairy breeds with similar size but different milk yield, the latter producing twice as much milk as the former (Pérez, 1997). The aim of this experiment was to compare, under the same feed conditions, dry matter intake and performance in late pregnancy and lactation and digestive pools of th...

The effects of fibre level (F) and forage particle size (S) on ruminal fermentation profile is often mediated through changes in feed intake, rates of digestion or passage, ruminal pH and/or bacteria population. Therefore, most in vivo studies have confounded the direct effect of F or S with changes in the rumen environment. In vitro systems allow...

The production of trans-10, cis-12 C18:2 isomer in the rumen is associated with milk fat depression. Two experiments were conducted to determine the effects of some additives on rumen fermentation and apparent biohydrogenation of linoleic (LA) and linolenic (LNA) acids, and the production of the trans-10, cis-12 C18:2 isomer associated with milk fa...

The ongoing academization of gastronomic studies indicates the necessity for a commonly accepted classification system for cooks that does not contradict scientific approaches. This work discusses the fundamentals used by chefs and scientists to classify unelaborated food products; proposes taxonomic gastronomy as a new interdisciplinary framework...

Interest in functional foods has increased in recent years, being the enrichment of milk with conjugated linoleic acid (CLA) one of the targeted products. The objectives of this research were: (a) To identify the source of current human daily recommendations for CLA (literature search); (b) To determine the effect of feeding strategies on CLA conce...

Five essential oil compounds in four doses (0, 50, 500, and 2000 mg kg⁻¹ of fresh forage) were sprayed on ryegrass forage before ensiling. Thymol, eugenol, and cinnamaldehyde at 2000 mg and carvacrol at 500 and 2000 mg inhibited deamination. Cinnamaldehyde at 2000 mg resulted in silages with 9.8% higher true protein.

Eighteen Simmental heifers were fed concentrate and barley straw offered as a total mixed ration (TMR) or separately as a free choice (FCH) to compare performance, behaviour, and meat quality. The heifers were assigned to treatments in a randomized complete block design. Animals were allotted to roofed pens with 3 animals per pen, and 3 pens per tr...

Ruminants are recognized sources of greenhouse gas (GHG) emissions. The objective of this paper was to estimate the carbon footprint of dairy and beef farms in different production systems in Spain. Component models for predicting all important sources of CH4, N2O, and CO2 from primary and secondary sources in dairy and beef production were estimat...

The ban on the use of antibiotics as growth promoters in animal feeds in the European Union has stimulated research on potential alternatives. Recently, propyl-propane thiosulfonate (PTSO), a stable organosulfurate compound of garlic, was purified. The objectives of the current study were to investigate the potential effects of PTSO on rumen microb...

Kinetics of nutrient degradation in the rumen is an important component of feed evaluation systems for ruminants. The in situ technique is commonly used to obtain such dynamic parameters, but it requires cannulated animals and incubations last several days limiting its application in practice. On the other hand, feed industry relies strongly on NIR...

Roughage in beef diets could be reduced or removed if replaced with less costly non-forage fiber sources, but there is little information about their effects on microbial fermentation and nutrient flow in different ruminal conditions. In the present experiment, eight dual-flow continuous culture fermenters (1320 ml) were used in three periods (5 da...

Abstract Text: Feeding polyunsaturated fatty acids (PUFA) to dairy cows results in milk fat depression (MFD) in some, but not all cows. The objective of this research was to compare the mRNA expression of enzymes involved in fatty acid (FA) synthesis in the mammary gland of cows resistant or sensitive to MFD resulting from feeding PUFA. Four cows...

Abstract Text: Feeding linseed to dairy cows results in milk fat depression (MFD), but there is a wide range of sensitivity, with some cows not showing any reduction in milk fat, while others having a strong MFD. The objective of this study was to compare the mRNA expression of transcripts expressed in pelleted milk cells in cows resistant or sen...

Abstract Text: Plant extracts have antimicrobial properties that may reduce the risk of disease and improve the health and performance of young animals. The objective of this experiment was to study the effect of an essential oil feed additive (EO; XT-6930; Pancosma, Switzerland) on the performance of milk-fed calves. Eight male Holstein calves w...

Abstract Text: Interest in functional foods has increased in recent years, being the enrichment of milk with conjugated linoleic acid (CLA) one of the targeted products. The objectives of this research were: a) to identify the source of human daily recommendations (literature search); b) to determine the effect of feeding strategies on CLA concen...

Abstract Text: The small intestine contains nutrient receptors that react to changes in the composition of ingested feed. The feed additive Sucram® (Pancosma, Switzerland) is an artificial sweetener that has been shown to increase absorption of glucose from the small intestine by activating sweet taste receptors in swine, this response results in...

Absorption of glucose from the lumen of the intestine into enterocytes is accomplished by sodium-glucose co-transporter 1 (SGLT1). In the majority of mammalian species, expression (this includes activity) of SGLT1 is upregulated in response to increased dietary monosaccharides. This regulatory pathway is initiated by sensing of luminal sugar by the...

Eight Simmental heifers (initial BW 313.4 ± 13.2 kg) were randomly assigned to 1 of 4 experimental treatments in a 4 × 4 double Latin square design. The experiment was performed in 4, 28-d periods. Treatments tested were a control diet in which barley straw was used as a fiber source (BS), and three diets where the main difference was the non-forag...

Considerando a necessidade de dar destino correto aos co-produtos gerados no processo de produção do biodiesel, bem como caracterizar nutricionalmente fontes alternativas de proteína para bovinos, o objetivo deste trabalho foi avaliar os parâmetros ruminais e o valor nutritivo de rações contendo 0, 2, 4 e 8 % de inclusão de torta de nabo forrageiro...

Considering the need to give the correct destination to co-products generated in the production of biodiesel, as well as nutritionally characterize alternative sources of protein for cattle, the objective of this study was to evaluate ruminal parameters and nutritional value of diets containing 0, 2, 4 and 8% replacement of cottonseed meal by radis...

Considerando a necessidade de dar destino correto aos co-produtos gerados no processo de produção do biodiesel, bem como caracterizar nutricionalmente fontes alternativas de proteína para bovinos, o objetivo deste trabalho foi avaliar os parâmetros ruminais e o valor nutritivo de rações contendo 0, 2, 4 e 8 % de inclusão de torta de nabo forrageiro...

A total of eight Simmental heifers (114 ± 3.2 days old and weighing 118 ± 3.8 kg BW) were used to study the effects of feeding method on intake and animal behaviour in a crossover design experiment. Treatments consisted of feeding concentrate and chopped barley straw as (1) choice (CH; concentrate and straw in separate feedbunks) or (2) total mixed...

Four beef Holstein heifers (BW = 438 ± 71 kg) fitted with a 1-cm i.d. plastic ruminal trocars were used in a 4 × 4 Latin square design to evaluate the effect of 3 doses of capsicum extract (CAP) on intake, water consumption, and ruminal fermentation in heifers fed a high-concentrate diet. Animals were fed (DM basis) 10% barley straw and 90% concent...

Subacute ruminal acidosis (SARA) is a common digestive disorder in cattle fed high concentrate diets, and it is generally defined as a reduction in ruminal pH below 6.0 that results in lower fibre digestion, changes in rumen fermentation profile, irregular intake and reduced performance. However, the true cause of the observed effects in the rumen...

Ruminal acidosis in feedlot cattle is a common metabolic disorder of digestive origin with significant economic and welfare implications. The main risk factors are high grain, low roughage diets because of their high rate and extent of degradation by rumen microbes. Diet formulation should therefore consider the proportion, method of processing and...

This preface outlines the context for initiating the special issue, comments on the review process, provides a brief summary of the papers in this issue and discusses some implications of these papers concerning rumen health.

Eight dual-flow continuous culture fermenters (1320ml) were used in two replicated periods of 7d (4d of adaptation and 3d for sampling) to study effects of pH (high=6.4 versus low=5.6) and fatty acid type (omega-3 versus omega-6) on ruminal microbial fermentation, lipolysis and apparent biohydrogenation, flow of fatty acid (FA) and DNA concentratio...

Two experiments were conducted to ascertain the effects of feeding an all-concentrate diet to growing heifers on performance, ruminal fermentation, behaviour and welfare. In experiment 1, eight tethered rumen fistulated Holstein heifers (143 ± 8.7 kg, initial BW) were used to study the effects of treatment on intake, ruminal changes and behaviour....

Eighty continental crossbred beef heifers (414.9 ± 37.9 kg of BW), 16 of which were ruminally cannulated, were used in a 52-d experiment with a generalized randomized block design, to assess if self-selection of dietary ingredients modulates ruminal pH and improves rumen function of feedlot finishing cattle. Treatments were total mixed ration [TMR;...

The efficiency of N utilization in ruminants is typically low (around 25%) and highly variable (10% to 40%) compared with the higher efficiency of other production animals. The low efficiency has implications for the production performance and environment. Many efforts have been devoted to improving the efficiency of N utilization in ruminants, and...

Dietary crude protein (CP) reduction is considered a useful strategy to minimize cow N excretion and NH(3) and N(2)O emissions. The aim of the current work was to relate dietary CP modification to whole-animal N balance and subsequent NH(3) and N(2)O concentrations on a tie-stall barn floor. The effect of temperature on NH(3) and N(2)O concentratio...

The objective was to evaluate the effects of an inhibitor of alpha-amylase and glucosidase (acarbose, Pfizer Limited, Corby, UK) on ruminal fermentation, blood metabolism and microbial profile in dairy cows in a 2x2 cross-over experiment. Eight Holstein cows fitted with rumen cannulas (milk yield, 24.3+/-2.35 kg/d, body weight, 622+/-54 kg, days in...

Dietary modifications in dairy cattle have been reported as a useful strategy to alter the composition of manure. Many reports have been published on how changes in dietary crude protein content and forage-to-concentrate ratio reduces animal nitrogen (N) excretion, but little information exists about the effect of diet modification on nitrous oxide...

Most feeding systems recognize that intestinal digestibility of rumen undegradable protein varies among feeds and different samples of the same feed (mainly in heat processed feeds). In spite of the evidence that intestinal digestibility of individual AA varies within feed, the difficulty in its determination results in the assumption that digestib...

The objectives of this experiment were to measure intestinal digestibility of AA in the rumen-undegraded protein fraction (RUP-AA) of distillers dried grains with solubles (DDGS) and fish meal (FM) samples and to determine whether these feeds contain a constant protein fraction that is undegradable in the rumen and indigestible in the small intesti...

Milk fat depression in cows fed high-grain diets has been related to an increase in the concentration of trans-10 C(18:1) and trans-10,cis-12 conjugated linoleic acid (CLA) in milk. These fatty acids (FA) are produced as a result of the alteration in rumen biohydrogenation of dietary unsaturated FA. Because a reduction in ruminal pH is usually obse...

The objectives of this experiment were to measure intestinal digestibility of AA in rumen undegradable protein (RUP-AA) in soybean meal (SBM) and expeller SBM (SoyPlus, West Central, Ralston, IA; SP) and to determine if these feeds contain a constant protein fraction that is undegradable in the rumen and indigestible in the small intestine, as assu...

Three soybean meal, 3 SoyPlus (West Central Cooperative, Ralston, IA), 5 distillers dried grains with solubles, and 5 fish meal samples were used to evaluate the modified 3-step in vitro procedure (TSP) and the in vitro immobilized digestive enzyme assay (IDEA; Novus International Inc., St. Louis, MO) for estimating digestibility of AA in rumen-und...

The effects of a dietary challenge to induce digestive upsets and supplementation with yeast culture on rumen microbial fermentation were studied using 12 Holstein heifers (277 +/- 28 kg of BW) fitted with a ruminal cannula, in a crossover design with 2 periods of 5 wk. In each period, after 3 wk of adaptation to a 100% forage diet, the dietary cha...

Four rumen-fistulated Holstein heifers (134 +/- 1 kg initial BW) were used in a 4 x 4 Latin square design to determine the effects of delaying daily feed delivery time on intake, ruminal fermentation, behavior, and stress response. Each 3-wk experimental period was preceded by 1 wk in which all animals were fed at 0800 h. Feed bunks were cleaned at...

Physiological changes in rumen fermentation during acidosis induction and its control using a multivalent polyclonal antibody preparation (PAP) were studied in a completely randomized experiment using 12 crossbred heifers (452 +/- 20 kg of BW). Treatments were control (CTR) or PAP. The acidosis induction protocol consisted of 3 periods: 3 mo of 100...

Dairy farm activities contribute to environmental pollution through the surplus N and P that they produce. Optimization of animal feeding and management has been described as a key strategy for decreasing N and P excretion in manure. Sixty-four commercial dairy farms were studied to assess the efficiency of N and P use in lactating herds and to ide...

Use of antibiotics as growth promoters in animal feeds has been banned in the European Union due to increasing concerns about the appearance of residues in meat and milk and antibiotic resistant strains of bacteria. Some essential oils (EO) modify rumen microbial activity and appear to be a 'natural' alternative to modify rumen microbial fermentati...

Four Holstein heifers (229±24kg BW) fitted with ruminal trocars were used in a 4×4 Latin square design experiment to evaluate effects of monensin (MON), anise extract (ANI) and capsicum (CAP) on rumen microbial fermentation. Heifers were fed a 100:900 forage:concentrate diet (157g CP/kg and 223g NDF/kg on a dry matter (DM) basis). Treatments were:...

Public concern over use of antibiotics in livestock production has increased in recent years because of their possible contribution to emergence of antibiotic resistant bacteria, and their transmission from livestock to humans. Accordingly, ruminant microbiologists and nutritionists have been exploring alternative methods of favorably altering rumi...

Four different plant secondary metabolites were screened for their effect on rumen biohydrogenation of forage long-chain fatty acids, using dual-flow continuous culture fermenters. Treatments were as follows: control (no additive), positive control (12 mg/L of monensin), and plant extracts (500 and 1,000 mg/L of triterpene saponin; 250 and 500 mg/L...

The objective of the present study was to examine the effects of increasing the number of heifers per concentrate feeding place on performance, behavior, welfare indicators, and ruminal fermentation of feedlot heifers. Seventy-two Friesian heifers were used in a factorial arrangement, with 3 treatments and 3 blocks of similar BW. Treatments consist...

Four ruminally fistulated Holstein heifers (BW = 264 ± 12 kg) were used in a 4 × 4 Latin square design experiment to determine the effect of increasing levels of sodium bicarbonate (BICARB; 0%, 1.25%, 2.50% and 5%, on concentrate dry matter (DM) basis) on DM intake (DMI), water consumption and ruminal fermentation. Sampling was carried out in the l...

Four Holstein heifers (264 ± 12 kg initial BW) were used in a 4 × 4 Latin square design with 21-day experimental periods to determine the effect of increasing levels of sodium bicarbonate (BICARB) (0%, 1.25%, 2.5% and 5%, of concentrate dry matter (DM) basis) on chewing and feed intake behavior when fed high-concentrate diets. Concentrate (13.41% C...

Low ruminal pH may occur when feeding high-concentrate diets. However, because the reduction in pH occurs at the same time as the amount of concentrate fed increases, the changes observed in rumen fermentation may be attributed to pH or the type of substrate being fermented. Our objective was to determine the contribution of pH and type of substrat...

Seventy-two Friesian calves (BW = 102.0 +/- 1.8 kg) were bought from a commercial calf farm and distributed to a factorial arrangement of treatments in a complete block design with 3 treatments and 3 blocks of similar fasted BW to study the effect of increasing the number of feeding places per pen on performance, behavior, and welfare indicators du...

A total of 356 early lactation multiparous Holstein cows were used in a randomized complete block design to determine the effects of feeding extruded linseed on milk production and composition, and reproductive performance. Forty of these cows were randomly selected to study the effects of extruded linseed on milk fatty acid (FA) profile, individua...

The negative effect of pH on rumen microbial fermentation has been associated with the total amount of time that pH is below a certain threshold. However, not only the time, but also the magnitude of the pH reduction, is important. Eight 1,325-mL dual-flow continuous culture fermenters were used in 2 replicated periods to determine the effect of th...

Ammonia derived from cattle, especially dairy cattle, is one of the main types of atmospheric pollution. The amounts of N in excreta and subsequent emissions of ammonia can be reduced by manipulating cattle diets. Ten lactating cows were fed diets supplying different N intake and forage:concentrate ratio and the resulting slurries obtained were app...

The objective was to evaluate whether the amount of concentrate offered in an automatic milking systems (AMS) would modify milking frequency, feeding behavior, and milk production. One hundred fifteen lactating cows were used in a cross-over design with 2 periods of 90 d each and 2 treatments: low concentrate (LC; up to 3 kg/d of concentrate at the...

The objectives were to compare the chemical composition, nutritive value, feed intake, milk production and composition, and presence in milk of transgenic DNA and the encoded protein Cry1Ab when corn silages containing 2 transgenes (2GM: herbicide tolerance: mepsps and insect resistance: cry1Ab) were fed as part of a standard total mixed ration (TM...

Four ruminally fistulated Holstein heifers (BW = 385 +/- 6.2 kg) were used in a 4 x 4 Latin square experiment to determine the effect of feeding frequency on intake, water consumption, ruminal fermentation, and feeding and animal behavior. The treatments consisted of different feeding frequencies: a) once daily (T1); b) twice daily (T2); c) 3 times...

Low ruminal pH affects rumen fermentation, with the effects being larger as the time at suboptimal pH increases. Eight 1,325-mL dual-flow continuous culture fermenters were used to examine the hypothesis that the negative effects of a single cycle of 12 h (experiment 1) or 8 h (experiment 2) at pH 5.5 can be reduced by splitting it into several cyc...

Microorganisms in the rumen degrade nutrients to produce volatile fatty acids and synthesize microbial protein as an energy and protein supply for the ruminant, respectively. However, this fermentation process has energy (losses of methane) and protein (losses of ammonia N) inefficiencies that may limit production performance and contribute to the...

An experiment was performed to evaluate the effect of extruding the cereal and/or the protein supplement of a compound feed for intensively reared calves on ruminal N metabolism using an in vitro culture system. A conventional compound feed was produced without extruding [treatment non-extruded (NE)], with the cereal blend extruded (CE), with the p...