bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of the voluntary intake of grass silages by beef cattle. 2. Principal component and ridge regression analyses
Authors: Rook A. J. , Dhanoa M. S. , Gill M. 
Published: September 2010

ABSTRACTData on individually recorded silage intake (SDMI), concentrate intake and live weight of steers and data on silage composition including toluene dry matter, pH, total nitrogen, ammonia nitrogen, volatile fatty acids, digestibility and fibre measures obtained from experiments at three sites were used.Correlation and principal component analyses indicated that there was severe collinearity among a number of the variables, particularly among various fermentation characteristics, between different measures of digestibility and between different measures of fibre. This collinearity was shown to have caused instability in least-squares multiple regression coefficients of silage intake on other variables previously obtained from the same data (Rook and Gill, 1990). Principal component regression and ridge regression allowed the derivation of new coefficients which were more stable and more in line with a priori expectations from experimental results. Linear functions of the original variables and the use of models containing fewer variables also proved effective in overcoming the problems of collinearity.Fermentation characteristics were shown to be the most important silage factors affecting intake and butyric acid was shown to be more important than other volatile fatty acids or ammonia nitrogen. Neutral-detergent fibre was found to be better related to intake than other fibre or digestibility measures.
The performance of ewes offered diets containing different proportions of perennial ryegrass and white clover silage in late pregnancy
Authors: Orr R. J. , Treacher T. T. 
Published: September 2010

ABSTRACTFinn Dorset ewes were offered forage ad libitum from week 16 of pregnancy until lambing and were either unsupplemented (U) or given 600 g/day of concentrates (S). Grass silage and white clover silage, ensiled separately and having similar dry matter concentrations, were offered in four mixtures with white clover proportions of 0, 0·20, 0·40 and 0·60 on a fresh basis. Forage intake was significantly higher for mixtures containing higher proportions of clover (9·1, 10·5, 12·3 and 13·6 g organic matter (OM) per kg live weight) and the ewes gained more weight (33, 65, 178 and 174 g/day) and had smaller losses in body condition score (–0·59, –0·49, –0·39 and –0·17). Higher proportions of clover in the diet in late pregnancy also resulted in significantly higher growth rates of lambs during lactation, when a common diet was offered.The number of foetuses carried in pregnancy had significant effects on intake and some aspects of performance. For ewes carrying singles, twins and multiples respectively, mean daily forage intakes were 12·2, 11·9 and 10·4 g OM per kg live weight and losses in body condition score were –0·05, –0·40 and –0·62.Offering the supplement reduced forage intake and for treatments U and S respectively, mean daily values were 12·6 and 10·2 g OM per kg live weight. Whilst the supplemented ewes had smaller losses in body condition score in late pregnancy (–0·54 v. –0·28), lamb birth weights and growth rates were significantly increased only for ewes which had carried three or more foetuses in pregnancy and reared their two heaviest lambs.
Predicting the time of ovulation in dairy cows using on-farm progesterone kits
Authors: McLeod B. J. , Foulkes J. A. , Williams M. E. , Weller R. F. 
Published: September 2010

ABSTRACTA protocol of infrequent, but strategically timed milk-sampling was established for predicting the time of ovulation, and thus the optimum time for insemination, in lactating dairy cows. In the experimental group (no. = 49), the time of ovulation was predicted on the basis of a fall in milk progesterone concentrations, which was identified by the use of ‘on-farm’ progesterone assay kits. Reproductive performance in these animals was compared with that in control cows (no. = 45) that were inseminated solely on the basis of oestrous detection by stockmen. The accuracy of ovulation prediction, and of oestrous detection, was assessed from progesterone profiles based on milk samples collected three times weekly from all 94 cows. These milk samples were analysed by laboratory enzyme-immunoassay after the end of the trial.Over the period during which milk samples were monitored with ‘on-farm’ progesterone kits, a total of 88 ovulations occurred in the experimental group. The progesterone-testing protocol accurately predicted 87 (99%) of these. Over the same period, there was a total of 81 ovulations in the control group and 63 (78%) of these were associated with correct oestrous detection. Conception rates to correctly timed insemination did not differ significantly between groups, but by the end of the three-cycle experimental period, significantly more of the cows in the experimental group (21·8%) than in the control group (4·8%; P < 0·05). In contrast, the use of ‘on-farm’ progesterone results to confirm oestrus avoided any mistimed inseminations (13% of inseminations in the control group). By using the milk-sampling and ‘on-farm’ progesterone-testing protocol, only 1% of ovulations were not accompanied by a correctly timed insemination. This compared with 22% of ovulations in the control group not associated with an insemination because oestrus was not detected. By ensuring that all ovulations are associated with a correctly timed insemination, herd reproductive performance can be significantly improved.
The effect of compound composition and silage characteristics on silage intake, feeding behaviour, production of milk and live-weight change in lactating dairy cows
Authors: Jackson D. A. , Johnson C. L. , Forbes J. M. 
Published: September 2010

ABSTRACTAn experiment was carried out to investigate the effects of compound composition and silage characteristics on silage intake, feeding behaviour and productive performance of dairy cows during the first 25 weeks of lactation. Over a period of 3 years, 36 lactating British Friesian cows (12 per year), in their third or later lactations, were divided into two groups. The cows in each group received either compound S, in which the principal energy source was cereal starch, or compound F containing a mixture of high quality digestible fibre. Cows given compound F ate 2·2 kg more silage dry matter per day (P < 0·05). The type of compound had no effect on the frequency of silage feeding and the time spent eating was significantly different only over weeks 10 to 25 of lactation (P < 0·05), with cows on compound F spending on average 20 min longer feeding per day. Cows on compound F produced 1·7 kg more milk per day than cows on compound S. Although there were no significant differences in the concentration of milk constituents, compound F was associated with higher yields of milk constituents. Significant differences were found between the years of experiment in the frequency of feeding (P < 0·05) and also in the concentration of milk protein and milk fat. There were no significant differences in the magnitude of live-weight change between treatments or year of experiment.
The effect of mixing unfamiliar individuals on the growth and production of finishing pigs
Authors: Tan S. S. L. , Shackleton D. M. , Beames R. M. 
Published: September 2010

ABSTRACTThe effect on productivity of mixing finishing pigs from different litters was studied. Two hundred and ten Yorkshire × Landrace pigs of about 76 kg were assigned in groups of six to each of four treatments. In treatment 1, pigs were retained as unmixed littermates while in treatments 2 and 3, three pigs from one litter were mixed with three pigs from another litter. Additionally pigs in treatment 3 were injected with a tranquilizer prior to mixing. In treatment 4, groups of five littermates were introduced into the pen of either a lighter weight or heavier weight pig. All groups were housed in 6·65 m2 partially slatted pens and fed from a communal food trough.Besides promoting aggression and fighting, mixing significantly depressed productivity, and both short-and long-term economic returns. Over the 3-week experimental period the proportional live-weight gains observed in the unmixed pigs over those of the mixed groups, were substantial: 0·099 over the 3: 3 mixed groups, 0·141 over the tranquilizer-treated groups, and 0·127 over the 5: 1 mixed groups. Consequently, mixing would necessitate additional inputs of food, housing, and labour because of the increased days to market.The tranquilizer not only did not eliminate fighting but had a long-term negative effect on production and was thus a contra-indicated expense. Introducing a single pig into a group in an occupied pen also lowered production, as did moving without mixing. However, moving effects were short lived and had minimal negative influences on overall productivity.
Repeatability and bias of estimated breeding values for dairy bulls and bull dams calculated from animal model evaluations
Authors: Uimari P. , Mäntysaari E. A. 
Published: September 2010

AbstractAn animal model and an approximative method for calculating repeatabilities of estimated breeding values are used in Finnish dairy cow evaluation. Changes in estimated breeding values over time as daughters accumulate were studied. Special emphasis was given to the accuracy and potential bias in the pedigree indices of young sires. The data set used was the same as in the national evaluation and the traits investigated were protein yield and somatic cell count. The average repeatability in evaluation of bulls without daughters was 0·37. The empirical repeatability defined as a squared correlation between the pedigree index and the final sire proof was only 0·15. The reduction in the repeatability was attributed to the selection on pedigree index. The upward bias observed in pedigree indices was 5 kg (approx. 0·3 of genetic standard deviation). The bias was caused by the overestimation of bull dams' breeding value. Also the proofs of bull sires increased after the second crop of daughters. The correlation between the evaluations of the same sire calculated from two separate equal size daughter groups was 0·91 when the bull had 10 to 50 daughters and 0·87 with over 100 daughters. This illustrates how the relative weight of the pedigree decreases while more progeny information is accumulated in the evaluation.
Accretion of total protein and individual amino acids by organs and tissues of growing lambs and the ability of nitrogen balance techniques to quantitate protein retention
Authors: MacRae J. C. , Walker A. , Brown D. , Lobley G. E. 
Published: September 2010

AbstractTwelve Suffolk-Finn Dorset lambs were reared from 25 to 40 or 25 to 55 kg body weight on either pelleted dried grass or a ration of pelleted grass plus barley (ratio 1:1) in a comparative slaughter experiment designed to determine the amounts of total nitrogen and individual amino acids accreted in different body components during growth. Nitrogen (N) balance measurements were determined frequently during this growth phase and accumulated N retentions were compared with the total N accretion determined by comparative slaughter. Total N and individual amino acids accumulated in carcass, wool, skin, offal and blood, head and feet, gastro-intestinal tract and liver were linearly related to body weight in all cases other than for cysteine in carcass. At 25 kg live weight, proportionately 0·52 of total body N was in carcass components, 0·115 in wool, 0·08 in skin, 0·10 in offal and blood, 0·095 in head and feet, 0·06 in the gastro-intestinal tract and 0·02 in liver. However as the animals grew from 25 to 55 kg, 0·256 of the total N accretion was in wool, which was rich in cysteine (98 g/kg total amino acid). Carcass accretion represented only 0·449 of total body N accretion. The N balance technique overestimated net protein accretion by 0·24 (s.e. 0·036).
Genetic parameters of lamb carcass characteristics at three end-points: fat level, age and weight
Authors: Pollott G. E. , Guy D. R. , Croston D. 
Published: September 2010

AbstractAlthough breed substitution is a very common method of rapidly altering the characteristics of a livestock population, within-breed selection for lamb carcass characters is becoming more widely used in the terminal sire breeds in Britain. Such selection schemes require accurate and applicable genetic parameters for the carcass traits of interest. This paper reports a genetic analysis of 11 traits measured on 3592 lamb carcasses using a derivative-free restricted maximum likelihood technique. Because of the trial design it was possible to estimate the genetic parameters of the traits at comparable fat cover, carcass weight and age at slaughter, using appropriate within-subclass covariates.Heritability estimates for muscle depth (0·23, s.e. 0·04), muscle width (0·32, s.e. 0·05), fat depth (0·31, s.e. 0·05), caliper fat (0·23, s.e. 0·04) and conformation (0·29, s.e. 0·05) were similar in the weight and age-corrected results. Heritabilities for fat cover (0·35, s.e. 0·05), daily carcass weight gain (0·63, s.e. 0·07), and leg conformation (0·44, s.e. 0·05) were higher with slaughter at fixed weight than at fixed age. The heritabilities of traits at comparable fat cover were similar to those at comparable age at slaughter with the exception of daily carcass weight gain, fat depth, caliper fat and leg conformation.The different measures of fat were highly correlated with each other. Conformation was moderately correlated with external fat score, carcass length and muscle depth. Muscle depth was moderately correlated with carcass length. Differences were found between genetic correlations calculated at equal weight, a common point of comparison in breeding schemes, and equal fat cover, a common end-point for slaughter lambs.
The effects of work on food intake and ingestive behaviour of draught cattle and buffalo given barley straw
Authors: Person R. A. , Smith D. G. 
Published: September 2010

AbstractIn the first experiment the animals were worked for 5h/day and/or given 17 h access to food. In the second experiment they were worked for 4 h/day and/or given 20 h access to food. When animals were prevented from feeding on barley straw for 7 h/day their dry-matter intake (DMI) was significantly less than when they were given 24 h access to food. When feeding was prevented for only 4 h/day food intake was not significantly different from that with 24-h access.A study of feeding behaviour (experiment 2) suggested that when most animals were deprived of food for 4 h they maintained similar intakes to those on ad libitum feeding by increasing their rate of eating, rather than by increasing the time they spent eating. Preventing food intake for 4 h/day was associated with little change in time spent ruminating during the day. On all treatments, the buffalo spent significantly less time eating and more time ruminating than the cattle.Work, during the periods when food was withheld, had little effect on the DMI of either the buffalo or cattle compared with restricted feeding. No rumination occurred during the time that the animals were at work. However on working days, time spent ruminating was similar to that seen on restricted feeding days, but the animals spent more time ruminating later in the day than when they were able to ruminate during the middle of the day.
Growth and body composition of Omani local sheep 1. Live-weight growth and carcass and non-carcass characteristics
Authors: Mahgoub O. , Lodge G. A. 
Published: September 2010

AbstractForty-five local Omani ram, wether and ewe lambs were reared from birth until slaughter at 18, 28 or 38 kg live weight (five of each ‘sex’ at each weight group) on an ad libitum concentrate diet and Rhodesgrass hay.Ram lambs grew faster from birth and reached predetermined slaughter weights earlier than wether and ewe lambs. At 28 kg live weight, ram lambs had: heavier heads, feet, reticulo-rumens and livers; higher muscle and bone and lower fat proportions in the carcass; lower muscle: bone and higher muscle: fat ratios; higher proportions of carcass but lower non-carcass fat than had wether and ewe lambs. The head, feet, alimentary tract, liver and heart of Omani sheep grew at a lower rate; the skin grew at a similar rate and the carcass grew at a rate faster than empty body weight (EBW). Relative to EBW, muscle grew at a similar rate, fat faster and bone slower. Both carcass and non-carcass fats grew at a rate higher than that of the growth of EBW, with non-carcass fat growing at a higher rate than that of carcass fat. The growth rate of omental fat was the fastest followed by kidney, mesenteric, subcutaneous, tail, scrotal, intermuscular and pelvic fats respectively.This study demonstrated that Omani sheep have good potential for growth if they are managed and fed satisfactorily. Omani sheep are early maturing for which reason it is recommended that they be slaughtered at lighter weights to avoid higher fat content in the carcass. Castration in Omani sheep is not recommended for production of meat lambs under intensive systems as it resulted in reduced growth rates and deposition of excess fat at lower slaughter weights.
Productivity and carcass composition of Friesian, Meuse-Rhine-Issel (MRI) × Friesian and Belgian Blue × Friesian steers
Authors: Keane M. G. 
Published: September 2010

AbstractOne hundred and twenty spring-born steers, comprising 40 Friesians (FR), 40 Meuse-Rhine-lssel (MRI) × Friesians (MR), and 40 Belgian Blue × Friesians (BB) were reared together from 3 weeks of age to the start of their second winter. During the second winter there was a 3 (FR, MR and BB breed types) × 2 (3 kg and 6 kg supplementary concentrates per head daily with grass silage ad libitum) × 2 (96- and 220-day finishing periods) factorial arrangement of treatments (10 animals per subgroup). Carcass weights and grades were recorded after slaughter at the end of the second winter, and one side from each of 96 carcasses (eight per subgroup) was dissected into bone, muscle, intermuscular fat and subcutaneous fat. A sample of m. longissimus from the 10th rib was chemically analysed. Slaughter weights and carcass weights per day from arrival to slaughter were 796, 813 and 828 (s.e.d. 11·7) g and 419, 440 and 457 (s.e.d. 7·1) g for FR, MR and BB, respectively. Corresponding carcass weights were 314, 329 and 342 (s.e.d. 4·5) kg. BB had better conformation than both FR and MR. BB also had a lower carcass fat score, lower proportions of bone, intermuscular fat and subcutaneous fat, a higher proportion of muscle and muscle with higher proportion of moisture and a lower proportion of lipid than FR and MR. The higher level of concentrates increased side iveight by 8 kg, but the overall effects on carcass composition were small. The longer finishing period increased side weight by 25 kg and was associated with significantly reduced proportions of bone and muscle and an increased proportion of fat. Allometric regression coefficients for carcass weight on slaughter weight, and for bone, muscle and fat weights on side weight were 1·19, 0·39, 0·80 and 2·16, respectively. It is concluded that despite the better carcass conformation of MR, there was little difference in carcass and muscle composition between FR and MR. BB, in addition to having a higher growth rate and better carcass conformation than FR, also had more muscle in the carcass, more of the total muscle in the higher value joints and a lower proportion of lipid in the muscle. It was calculated that FR, MR and BB would have similar proportions of separable fat in the carcass at approximate carcass weights of 300, 320 and 400 kg, respectively.
Effect ofSaccharomyces cerevisiaeyeast culture supplement on ruminal metabolism in buffalo calves given a high concentrate diet
Authors: Kumar U. , Sareen V. K. , Singh S. 
Published: September 2010

AbstractThe effect of inclusion of live yeast culture (YC, Saccharomyces cerevisiae plus growth medium) in a high concentrate diet given to buffalo (Bubalus bubalis) calves on the rumen microbial population and fermentation pattern and in sacco dry matter disappearance of dietary constituents was examined. Six rumen-fistulated buffalo calves of about 120 kg live iveight were divided into two equal groups. The control group was given a diet consisting of, on a dry-matter basis, 0·90 kg ivheat straw, 1 kg berseem (Trifolium alexandrinum) and ISO kg concentrate per day per calf and the yeast group the above diet plus 5 g YC which was put directly into the rumen via the fistula. After feeding this diet for 6 weeks (supplementation period), inclusion of YC was stopped and both groups were given the control diet for a period of 3 weeks to examine the performance of the YC group after withdrawal of YC. At week 4 of YC supplementation the pH was significantly increased (P< 0·01) and lactate concentration was decreased (P< 0·01) in the rumen fluid for up to 6 h post feeding. The number of total bacteria, total viable bacteria, cellulolytic bacteria, amylolytic bacteria and protozoa were increased proportionately by 0·554 (P< 002), 0·482 (P<0·01), 0·670 (P<0·01), 0·077 (P > 0·05) and 0·079 (P>0·05), respectively. The concentrations of total volatile fatty acids, particularly at 4 h post feeding (P< 0·01), acetate fP< 0·01) and propionate and the acetate to propionate ratio were higher in the YC compared with the control group. On YC inclusion, the concentration of ammonia-nitrogen was decreased while that of trichloracetic acid insoluble protein was marginally increased. All these differences in rumen variables started to disappear on YC withdrawal and values returned to control levels by the 3rd week after YC withdrawal. YC supplementation increased the in sacco dry-matter disappearance of various dietary components particularly after 3, 6 and 22 h incubation.
Consequences of inbreeding for financial returns from sheep
Authors: Wiener G. , Lee C. J. , Woolliams J. A. 
Published: September 2010

AbstractThe effects of inbreeding on the gross financial returns from ezues have been studied in a flock of sheep comprising three hill breeds and Ihe crosses among them. Each of these groups mis represented In non-inbred sheep (purebred and crossbred, designated O2, and F2, respectively) and four classes of inbreeding (inbreeding coefficients (F): 0·25, 0·375, 0·50 and 0·59). A second non-inbred class ums represented by crosses of inbred lines.Gross lifetime income per eive derived from the sale of lamps for slaughter, cast ezves and wool was reduced by inbreeding in an almost linear fashion (between the O2/F2 and the F 0·50 class) at a rate of £1·27 (at 1992 prices) for ench 0·01 (percentage point) increase in the level of inbreeding — an overall reduction to 0·35 of the O2/F2 level. Line crosses gave a better return than the other non-inbred sheep. When expressed in terms of ewe metabolic body weight (M0·73) the decline with inbreeding was less —an overall reduction to 0·4 of the O2/F, income. Inbreeding of Ihe lamb caused a further decline in output independent of the inbreeding of the ezve.