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ABSTRACT: The effects of maturity of maize at harvest, level of inclusion and potential interactions on the performance, carcass composition, meat quality and potential concentrate-sparing effect when offered to finishing beef cattle were studied. Two maize silages were ensiled that had dry matter (DM) concentrations of 217 and 304 g/kg and starch concentrations of 55 and 258 g/kg DM, respectively. Grass silage was offered as the sole forage supplemented with either 4 or 8 kg concentrate/steer daily or in addition with one of the two maize silages at a ratio 0.5 : 0.5, on a DM basis, maize silage : grass silage supplemented with 4 kg concentrate daily. The two maize silages were also offered as the sole forage supplemented with 4 kg concentrate/steer daily. The forages were offered ad libitum. The six diets were offered to 72 steers (initial live weight 522 s.d. 23.5 kg) for 146 days. There were significant interactions (P < 0.05) between maize maturity and inclusion level for food intake, fibre digestibility and daily gain. For the grass silage supplemented with 4 or 8 kg concentrate, and the maize silages with DM concentrations of 217 and 304 g/kg offered as 0.5 or 1.0 of the forage component of the diet, total DM intakes were 8.3, 9.8, 8.9, 8.2, 9.2 and 9.8 kg DM/day (s.e. 0.27); live-weight gains were 0.74, 1.17, 0.86, 0.71, 0.88 and 1.03 kg/day (s.e. 0.057); and carcass gains were 0.48, 0.73, 0.56, 0.46, 0.56 and 0.63 kg/day (s.e. 0.037), respectively. Increasing the level of concentrate (offered with grass silage), maize maturity and level of maize inclusion reduced (P < 0.05) fat b* (yellowness). The potential daily concentrate-sparing effect, as determined by carcass gain, for the maize silages with DM concentrations of 217 and 304 g/kg offered as 0.5 and 1.0 of the forage component of the diet were 1.3, -0.3, 1.3 and 2.4 kg fresh weight, respectively. It is concluded that the response, in animal performance, including maize silage is dependent on the stage of maturity and level of inclusion in the diet. Maize silage with a DM of 304 g/kg offered ad libitum increased carcass gain by 31%, because of a combination of increased metabolizable energy (ME) intake and improved efficiency of utilization of ME, and produced carcasses with whiter fat.
animal 12/2012; · 1.74 Impact Factor
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ABSTRACT: The aim of the present study was to assess the effects of Holstein-Friesian (HF) and Norwegian (N) dairy cattle genotypes on lameness parameters in dairy cattle within different production systems over the first 2 lactations. Following calving, HF (n = 39) and N (n = 45) heifers were allocated to 1 of 3 systems of production (high level of concentrate, low level of concentrate, and grass-based). High- and low-concentrate animals were continuously housed indoors on a rotational system so that they spent similar amounts of time on slatted and solid concrete floors. Animals on the grass treatment grazed from spring to autumn in both years of the study, so that most animals on this treatment grazed from around peak to late lactation. Claw health was recorded in both hind claws of each animal at 4 observation periods during each lactation as follows: 1) -8 to 70 d postcalving, 2) 71 to 150 d postcalving, 3) 151 to 225 d postcalving, and 4) 226 to 364 d postcalving. Sole lesions, heel erosion, axial wall deviation, sole length of the right lateral hind claw (claw length), right heel width, and right lateral hind heel height were recorded as well as the presence of digital dermatitis. The N cows had lower (better) white line and total lesion scores than HF cows. Cows on the high- and low-concentrate treatments had better sole and total lesion scores than cows on the grass treatment. The HF cows had better locomotion scores than N cows. Breed and production system differences were observed with respect to claw conformation, including claw length, heel width, and heel height. Digital dermatitis was associated with worse sole lesion scores and interacted with production system to influence white line lesion scores and maximum heel erosion scores. This study shows that genetic, environmental, and infectious factors are associated with hoof pathologies in dairy cows.
Journal of Dairy Science 06/2009; 92(5):2174-82. · 2.56 Impact Factor
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ABSTRACT: A completely randomised design study involving 132 continental crossbred beef steers was undertaken to evaluate the effects of method of grain treatment and feed level, and grass silage feed value on animal performance, carcass characteristics and meat quality of beef cattle. Winter wheat was harvested and the grain was stored either ensiled crimped and treated with 4.5 l/t of a proprietary acid-based additive (crimped), ensiled whole and treated with 20 kg feed-grade urea per t (urea) or stored conventionally in an open bin treated with 3 l propionic acid per t. Two grass silages, of contrasting feed value (L and H) were ensiled. For the conventional, crimped and urea treatments, grain dry matter (DM) concentrations were 802, 658 and 640 g/kg, respectively. For the L- and H-feed value silages, DM concentrations were 192 and 240 g/kg and D values were 671 and 730 g/kg DM, respectively. The silages were offered as the sole forage supplemented with either conventional, crimped or urea-treated grain-based concentrate at either 3.5 or 6.0 kg DM per steer per day. The grain supplement consisted of 850 and 150 g/kg DM of grain and citrus pulp, respectively. For the conventional, urea and crimped treatments, DM intakes were 8.85, 9.43 and 9.04 kg/day (standard error (s.e.) = 0.129); estimated carcass gains were 0.60, 0.55 and 0.61 kg/day (s.e. = 0.020), respectively. For the low- and high- feed value grass silages, estimated carcass gains were 0.56 and 0.61 kg/day (s.e. = 0.014), respectively. For the low and high grain feed levels, estimated carcass gains were 0.56 and 0.61 kg/day, respectively. Grain treatment, grain feed level or silage feed value did not alter (P > 0.05) meat quality, lean colour or fat colour. There were significant silage feed value × grain feed level interactions (P < 0.05) for final live weight (LW) and daily live-weight gain (DLWG). Increasing grain feed level increased final LW and DLWG when offered with the low-feed value silage, however, grain feed level had no effect on final LW or DLWG when offered with the high-feed value silage. It is concluded that urea treatment of grain increased silage intake and feed conversion ratio (kg DM intake per kg carcass) and tended to decrease carcass gain. Crimping provides a biologically equally effective method to store grain as conventional methods. Improving grass silage feed value had a greater impact on animal performance than increasing grain feed level by 2.4 kg DM per day.
animal 01/2008; 2(1):149-59. · 1.74 Impact Factor
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ABSTRACT: Data from 286 beef cattle, obtained in total diet digestibility assessments, were used to examine effects of dietary and animal factors on N excretion in feces and urine and to develop prediction equations for N excretion in beef cattle. The animals used were mainly from beef breeds, at various ages (from growth to finishing) and live BW (153 to 580 kg), and offered diets containing grass silage at production feeding levels. Dietary forage proportion ranged from 199 to 1,000 g/kg of DM and dietary CP concentration from 108 to 217 g/kg of DM. Linear and multiple regression techniques were used to examine relationships between the efficiency of N utilization and dietary and animal variables with the experimental effects removed. The statistical analysis indicated that N excretion was related positively (P < 0.001) to live BW and intakes of DM, N, and ME, and negatively (P < 0.001) to dietary forage proportion. The prediction equation for N excretion, developed using N intake alone, produced a large r2 (0.898) and a small SE (12.3). Addition of live BW and forage proportion as supporting predictors to this relationship only marginally increased R2 to 0.915 and reduced SE to 11.2. Nitrogen excretion was less well related to live BW (r2 = 0.771, SE = 18.5) than to N intake. Addition of N intake as a proportion of DMI or ME intake to the relationship between live BW and N excretion increased R2 to 0.824 and reduced SE to 16.2. The internal validation of these equations revealed that using N intake as the primary predictor produced a very accurate prediction of N excretion. In situations where data on N intake are not available, prediction equations based on live BW and dietary N concentration together can produce a relatively accurate assessment of N excretion. A number of mitigation strategies to reduce N excretion in feces and urine in beef cattle are discussed, including manipulation of dietary N concentration, diet quality, and level of feeding. The prediction equations and mitigation strategies developed in the current study provide an approach for beef producers to quantify N excretion against production and to develop their own mitigation strategies to reduce N excretion.
Journal of Animal Science 08/2007; 85(8):1982-9. · 2.10 Impact Factor
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ABSTRACT: A randomised design involving 66 continental cross beef steers (initial live weight 523 kg) was undertaken to evaluate the effects of the inclusion of maize or whole-crop wheat silages in grass silage-based diets on animal performance, carcass composition, and meat quality of beef cattle. Grass silage was offered either as the sole forage or in addition to either maize or whole-crop wheat silages at a ratio of 40:60, on a dry matter (DM) basis, alternative forage: grass silage. For the grass, maize, and whole-crop wheat silages, DM concentrations were 192, 276, and 319 g/kg, ammonia-nitrogen concentrations were 110, 90, and 150 g/kg nitrogen, starch concentrations were not determined, 225, and 209 g/kg DM and in vivo DM digestibilities were 0.69, 0.69, and 0.58; respectively. The forages were offered ad libitum following mixing in a paddle type complete diet mixer wagon once per day, supplemented with either 3 or 5 kg concentrates per steer per day, in two equal feeds, for 92 days. For the grass, grass plus maize and grass plus whole-crop wheat silage-based diets food intakes were 8.38, 9.08, and 9.14 kg DM per day, estimated carcass gains were 514, 602, and 496 g/day and carcass weights were 326, 334, and 325 kg; respectively. Altering the silage component of the diet did not influence carcass composition or meat eating quality. Increasing concentrate feed level tended ( P = 0.09) to increase estimated carcass fat concentration and increased sarcomere length ( P < 0.05), and lean a* ( P < 0.01), b* ( P < 0.05), and chroma ( P < 0.01). There were no significant silage type by concentrate feed level interactions for food intake, steer performance, carcass characteristics or meat eating quality. It is concluded that replacing grass silage with maize silage increased carcass gain, and weight due to higher intakes, and improved utilisation of metabolisable energy. Whilst replacing grass silage with whole-crop wheat silage increased live-weight gain, the reduced dressing proportion resulted in no beneficial effect on carcass gain, probably due to increased food intakes of lower digestible forage increasing gut fill. Meat quality or carcass composition were not altered by the inclusion of maize or whole-crop silages in grass silage based diets.
animal 05/2007; 1(4):613-23. · 1.74 Impact Factor
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ABSTRACT: A changeover design experiment involving thirty-six 3-month-old Friesian male calves (mean initial live weight 127 kg) was carried out to evaluate a bacterial inoculant based on a single strain of Lactobacillus plantarum (Ecosyl, ICI) as a silage additive. On 25–31 August 1988, nine silages were harvested using double-chop forage harvesters from the second regrowth of three swards, namely permanent pasture which had received 100 kg N ha−1 and perennial ryegrass which had received either 100 or 150 kg N ha−1. Herbages (mean DM and WSC concentrations 144 and 11·2 g kg−1 respectively) from each sward were treated with either no additive, formic acid (2·4 1 t−1) or the inoculant (3·3·1 t−1) and were ensiled in 126 silos of 0·8 t capacity. The only effects of the inoculant on chemical composition of the silages were a decrease in modified acid detergent fibre and an increase in endotoxin and crude and true protein concentrations. Silages were offered ad libitum and supplemented with 1·0 kg of concentrates per head daily for three periods each of 3 weeks in a partially balanced changeover design experiment. Digestibilities of the total diets were determined at the end of the experiment. For the untreated, formic acid-treated and inoculant-treated silages, silage dry matter intakes were respectively 3·58, 3·66 and 3·67 (s.e. 0·044) kg d−1, estimated metabolizable energy (ME) intakes were 46·1, 46·7 and 47·1 (s.e. 0·44) MJ d−1, energy digestibilities were 0·727, 0·727 and 0·738 (s.e. 0·0046) and organic matter digestibilities were 0·770, 0·771 and 0·788 (s.e. 0·0042). Rumen degradabilities of the silages were determined using two rumen-fistulated cows. Mean dry matter and nitrogen degradabilities for the control, formic acid-treated and inoculant-treated silages, assuming an outflow rate of 0·05 h−1, were 10·508, 0·49, 0·491 and 0·702, 0·676 and 0·729. It is concluded that the inoculant significantly increased the digestibility of the silages but did not affect dry matter or ME intake.
Grass and Forage Science 04/2006; 49(3):284 - 294. · 1.10 Impact Factor
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ABSTRACT: The data used in the present study were derived from a 2 (genotype) x 2 (plane of nutrition) factorial design production study using Holstein-Friesian (n = 32) and Norwegian (n = 32) first-lactation dairy cattle offered grass silage-based diets from 1 to 44 wk of lactation. The high nutrition diet had concentrate inclusions (g/kg of dry matter) of 600, 500, and 400 for lactation days of < 101, 101 to 200, and > 200, respectively, and the low nutrition diet included concentrates at 300, 200, and 100 for the same periods. Dietary metabolizable energy (ME) concentrations were measured in calorimetric chambers at lactation d 80, 160, and 240 respectively, and then applied to production data to calculate ME intake. From wk 1 to 44 of lactation, Holstein-Friesian cows had a consistently lower accumulated live weight gain and body condition score, and a consistently higher ME intake and milk energy output than Norwegian cows, irrespective of the plane of nutrition. Compared with Norwegian cows using mean data derived from the 2 planes of nutrition, Holstein-Friesian cows produced a significantly higher proportion of milk energy output over ME intake in early and mid lactation, although this increase was not significant in late lactation. In contrast, Holstein-Friesian cows partitioned a significantly lower proportion of ME intake into body tissue than Norwegian cows in early lactation, although the differences were not significant in mid or late lactation. When ME intake and energy used for maintenance, milk, and body tissue were taken into account, the efficiency of ME use for lactation was similar between the 2 genotypes offered the high or low concentrate diet during the whole lactation. It is concluded that Holstein-Friesian cows can produce more milk energy than Norwegian cows, mainly as a result of higher ME intake and because of a greater ability to partition more energy into milk and less into body tissue. The effect on energy partitioning mainly occurs in early and midlactation and is particularly evident with high concentrate diets.
Journal of Dairy Science 04/2006; 89(3):1031-42. · 2.56 Impact Factor
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ABSTRACT: The effects of concentrate energy source on feeding behaviour and energy utilization, when offered with grass silages of differing intake characteristics, were studied in lactating dairy cows. A total of five silages, which differed in fermentation and intake characteristics, were prepared. Silages A, B and D and silages C and E were harvested from primary regrowths and secondary regrowths respectively of predominantly perennial ryegrass swards. Herbage was ensiled either pre-wilted or unwilted and either untreated or treated with a bacterial inoculant or formic acid based additives. Five concentrates (0s, 25s, 50s, 75s and 100s) were formulated to contain similar concentrations of crude protein, effective rumen degradable protein and metabolizable energy (ME) but using different carbohydrate sources to achieve a wide range of starch concentrations. The silages were offered ad libitum, supplemented with 10 kg concentrates per head per day. In experiment 1, a partially balanced change-over design experiment involving 50 lactating dairy cows was undertaken to examine the effects of concentrate energy source on silage feeding behaviour. Silages A, B, C, D and E were each supplemented with concentrates Os, 25s, 50s, 75s and 100s. Concentrate energy source did not alter (P > 0·05) silage feeding behaviour. The number of meals per day decreased (P < 0·01) as silage dry-matter concentration increased. Experiment 2, a completely randomized experiment involving 18 lactating dairy cows, was undertaken to examine the effects of concentrate energy source on energy utilization with cows offered silages B, C and D. These were supplemented with 10 kg/day of concentrates Os, 50s and 100s. Concentrate energy source had little effect (P > 0·05) on ME intake, energy output or on the efficiency of utilization of ME for lactation (k1). In experiment 3, the effect of concentrate energy source on silage preference was examined in a factorial design experiment involving 12 lactating dairy cows. Silages B, C and D were supplemented with concentrates Os, 50s and 100s. Concentrate energy source did not alter (P > 0·05) silage preference. It is concluded that with silages of differing fermentation and intake characteristics but of similar digestibility, concentrate energy source had no effect on feeding behaviour, silage preference or energy utilization. Furthermore there was no evidence of concentrate energy source by silage type interactions on silage feeding behaviour and preference, or energy utilization.
Animal Science. 09/1998; 67(02):225 - 236.
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ABSTRACT: A partially balanced change-over design experiment was made to examine the effects of concentrate energy source on the voluntary food intake and animal performance of 50 lactating dairy cows offered a diverse range of grass silages. The silages were also offered as the sole diet to 10 dairy cows in a partially balanced change-over design experiment. A total of five silages were prepared. Silages A, B and D and silages C and E were harvested from primary regrowths and secondary regrowths respectively of predominantly perennial ryegrass swards. Herbage was ensiled either pre-wilted or unwilted and either untreated or treated with a bacterial inoculant or formic acid based additives. For silages A, B, C, D and E, dry matter (DM) concentrations were 473, 334, 170, 170 and 256 (s.e. 4·0) g/kg, pH values 4·42, 4·01, 4·88, 4·46 and 3·91 (s.e. 0·059), ammonia-nitrogen (N) concentrations 86, 88, 289, 182 and 135 (s.e. 10·6) glkg total N and in vitro DM apparent digestibilities 0·76, 0·76, 0·75, 0·73 and 0·75 (s.e. 0·009) respectively. When offered as the sole diet DM intakes were 14·1,14·7,10·5,10·1 and 11·5 (s.e. 0·50) kg/day. Five concentrates were formulated to contain similar concentrations of crude protein, effective rumen degradable protein (ERDP), metabolizable energy (ME) and fermentable ME (FME) but using different carbohydrate sources to achieve a wide range of starch concentrations. For the low and high starch concentrates, starch concentrations were 50 and 384 g/kg DM, and acid-detergent fibre concentrations were 128 and 75 g/kg DM respectively. The silages were offered ad libitum supplemented with 10 kg concentrate per head per day. For silages A, B, C, D and E silage DM intakes were 10·6, 10·5, 8·5, 8·6 and 9·0 (s.e. 0·37) kg/day and milk yields 23·9, 28·1, 26·2, 26·1 and 25·0 (s.e. 0·76) kg/day respectively. Concentrate energy source did not influence (P > 0·05) silage DM intake, diet apparent digestibility or the yields of milk or fat plus protein. For concentrates containing 50, 131, 209, 310 and 384 g starch per kg DM, milk protein concentrations were 32·0, 32·2, 32·5, 33·0 and 33·6 (s.e. 0·13) glkg, milk fat concentrations were 44·5, 43·9, 43·8, 43·3 and 43·1 (s.e. 0·35) glkg and urinary allantoin concentrations 15·2,15·4, 17·0, 1.7·6 and 18·0 mmolll respectively. Increasing starch intake resulted in positive and negative linear relationships for milk protein (P < 0·01, R2 = 0·96) and fat (P < 0·01, R2 = 0·96) concentrations respectively. There were no significant concentrate energy source × silage type interactions on silage intake or yields of milk or fat plus protein (P > 0·05). However there was a concentrate energy source × silage type interaction on milk fat yield (P > 0·05). It is concluded that, with silages of varying fermentation and intake characteristics but similar apparent digestibility, there were no concentrate energy source × silage type interactions on food intake, milk composition or milk yield. Also concentrate energy source had no effect on silage DM intake or milk yield. However increasing starch intake linearly increased milk protein concentration, probably due to increased microbial protein synthesis and decreased milk fat concentration.
Animal Science. 01/1998; 66(01):21 - 33.
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ABSTRACT: The effect of level and source of nutrients in late gestation on food intake, milk yield, milk composition and fertility in the subsequent lactation were evaluated in a randomized block design experiment involving 76 cows. Four experimental diets, based on grass silage, were offered to provide two levels of metabolizable energy (ME) intake (80 and 125 MJ/cow/day) either from 100:0 or 40:60 forage:concentrate (F:C) ratios for the last 28 days of gestation. Post-calving all cows were offered the same grass silage supplemented with 7 kg/day concentrates. For treatments 80 ME, 125 ME and 100:0 F:C, 40:60 F:C total dry matter (DM) intakes were 6.8, 10.5, 9.0 and 8.4 kg DM/day and ME intakes were 80, 126, 102 and 104 MJ/day, respectively, during the last 4 weeks of gestation. For weeks 1–16 of the subsequent lactation, treatment 125 ME increased milk fat content and yield but had no effect on food intake, milk protein content or onset of cyclicity. Treatment 125 ME increased condition score and live weight at calving. Altering the F:C ratio of the diets in late gestation had no effect on food intake, milk yield, milk composition or on the onset of cyclicity in the subsequent lactation. Cow parity and level of nutrient intake in late gestation provided the best fit relationships for the yields of fat and fat plus protein (R2 relationships=0.49 and 0.52, respectively) during weeks 1–16 of lactation. It is concluded that increasing nutrient intake in late gestation increased milk fat content and yield but had no effect on milk protein concentration. The improved milk fat content and yield observed in a previous study was due to increased nutrient intake rather than altering the F:C ratio. Furthermore there was no measurable benefit in food intake or animal performance in the subsequent lactation through feeding concentrates in late gestation.
Livestock Production Science.
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ABSTRACT: Five models commonly used to predict food intake of housed lactating dairy cattle were evaluated in the present study. Data from 2425 individual cows from 27 studies, undertaken at three research centres within the British Isles, were collated. The diet and cow characteristics differed considerably between studies with total dry matter intakes (DMI) varying from 8.5 to 29.4 kg/day (mean 17.0, S.D.=3.06), silage DMI varying from 3.8 to 18.8 kg/day (mean 9.4, S.D.=2.28) and milk yield varying from 7.7 to 49.7 kg/day (mean 26.5, S.D.=6.68). Predicted total DMI using the five equations, which incorporated a range of animal, feed and environmental variables, were compared against actual DMI using the mean-square prediction error (MSPE). The mean actual intake for the data set was 17.0 kg DM/day and the biases for the five models were: −0.03, +0.88, −2.18, −2.88 and −2.06 kg DM/day with MSPEs of 2.9, 5.5, 8.9, 11.4 and 10.8, respectively. It is concluded that with diets based on grass silage as the sole forage, actual DMIs are likely to be much lower than those predicted by three of the current models commonly used within the industry to formulate rations for lactating dairy cattle. Furthermore, the current evaluation clearly highlights the need for new models to accurately predict DMI for lactating dairy cows offered grass silage-based diets.
Livestock Production Science.
