bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting food intake in dairy heifers from early lactation records
Authors: Simm G. , Persaud P. , Neilson D. R. , Parkinson H. , McGuirk B. J. 
Published: September 2010

ABSTRACTNucleus breeding schemes for dairy cattle give opportunities for selection on characteristics other than milk production, such as food intake or efficiency, and for the application of reproductive technologies such as embryo transfer. The emphasis in such schemes involving embryo transfer will be on early lactation measurements of production and food intake, to minimize generation intervals. The aim of this study was to examine the value of early lactation measurements of food intake and other characteristics in predicting longer-term food intake. Intakes of a complete diet, offered ad libitum, were available for 101 heifers up to week 38 of lactation, from the Edinburgh School of Agriculture's Langhill herd. Partial correlations between weekly dry-matter (DM) or metabolizable energy (ME) intakes in early lactation and cumulated intakes to week 38 of lactation, after fitting year and month of calving as fixed effects, and proportion of Holstein blood as a covariate, ranged from 0·27 for week 1, to 0·70 for week 12. Cumulated ME intakes, up to week 38, were regressed on shorter measures of ME intake, together with fat plus protein yield in weeks 1 to 10 of lactation. Other independent variables, such as point estimates of, or changes in, live weight, condition score and backfat depth did not further increase the precision of prediction. The means and standard deviations for milk yield, DM intake and ME intake up to week 38 of lactation were 5877 (s.d. 1087) kg, 4070 (s.d. 400) kg and 51579 (s.d. 4614) MJ respectively. For a fixed duration of intake recording, measurements taken later in lactation gave the most precise prediction of 38-week ME intake (e.g. residual s.d.s from models including 4-week cumulated ME intakes in weeks 1 to 4, 3 to 6 and 5 to 8 of lactation were 2865, 2636 and 2501 MJ respectively, with R2 values of 0·62, 0·67 and 0·71). Shorter periods of intake recording started in week 5 of lactation gave slightly more precise prediction than longer periods of recording started in weeks 1 to 4 (e.g. residual s.d.s from models including cumulative ME intakes in weeks 1 to 10, 3 to 10 and 5 to 10 were 2391, 2298 and 2277 respectively, with R2 values of 0·69, 0·75 and 0·76). These results have implications for the cost: benefit of food intake recording in breeding schemes.
Genetic and phenotypic parameters for yield, food intake and efficiency of dairy cows fed ad libitum 1. Estimates for ‘total’ lactation measures and their relationship with live-weight traits
Authors: Persaud P. , Simm G. , Hlll W. G. 
Published: September 2010

ABSTRACTRecords on milk yield, fat plus protein yield, food intake, food efficiency, calving live weight and mean live weight, up to 26 and 38 weeks of lactation, were obtained from dairy cows, fed ad libitum, in the Edinburgh School of Agriculture's Langhill herd. The data were divided into first and later lactations and restricted maximum likelihood analyses carried out on heifer, cow and pooled data, fitting an animal model, with repeat lactations as an additional random effect. Univariate analyses were done after canonical transformation of heifer data and approximate canonical transformation of cow and pooled data. Heritability estimates for food efficiency and food intake, from pooled data, were 0·13 (s.e. 0·09) and 0·37 (s.e. 0·11) for 26-week and 0·13 (s.e. 0·12) and 0·52 (s.e. 0·14) for 38-week lactation periods, respectively. Over the same periods, estimates for milk yield were 0·20 (s.e. 0·08) and 0·20 (s.e. 0·11), respectively. Estimates from the analyses of cow and heifer data separately were higher, as were their standard errors. Genetic correlations between milk production traits and efficiency, from the pooled data analysis, ranged from 0·44 to 0·61 and those between milk production traits and food intake from 0·32 to 0·74. Genetic correlations between live-weight traits and efficiency ranged from −0·81 to −;0·99, and those between food intake and live-weight traits from 0·28 to 0·46. The results indicate that when selection is on yield, the correlated responses in efficiency may be smaller under ad libitum feeding, compared with published values where cows were given food according to yield. Including live weight in the selection criterion may give higher responses in efficiency compared with selection on yield alone. In MOET nucleus schemes it may be worthwhile to include food intake or efficiency directly in the selection criteria.
Correlated changes in growth patterns and overall production efficiency following selection for testis size adjusted for body weight in young male lambs
Authors: Lee G. J. , Haley C. S. , Land R. B. 
Published: September 2010

ABSTRACTTwo divergent lines of sheep were produced by selection on an index of testis diameter adjusted for body weight at 6, 10 and 14 weeks of age. There were correlated changes in growth patterns, such that animals in the high and low lines were of a similar weight at birth, but thereafter, the low line became progressively heavier than the high line. After 11 years of selection there was a 7-kg difference between the mean body weight of females in the two lines at 1·5 years of age and a 12-kg difference at 2·5 years. There was little evidence of any accompanying changes in body shape or in carcass composition. High-line females of all reproductive ages had a significantly higher fertility. High-line lambs had a significantly lower mortality and, at the end of selection, had an estimated probability of survival to 210 days of 0·25, 013 and 003 higher than in lambs from the low line, in lambs from 1-, 2- and 3-year-old dams respectively. The estimated number of lambs alive at 210 days per ewe mated was 0·30, 0·38 and 0·34 higher in the high line for ewes of 1, 2 and 3 years of age, but low-line lambs were 3 kg heavier on average at 210 days. The combined impact of improved ewe performance and changes in growth patterns led to a predicted greater production efficiency in the high line. It was estimated that, after 11 years of selection on the index of weight adjusted testis diameter, 0·62, 0·71 and 0·74 kg of high-line ewe at 1, 2 and 3 years of age, respectively, would be needed to produce the same weight of lamb at 210 days as 1 kg of low-line ewe. Improved ewe performance had a much larger impact on the changes in comparative efficiency than changes in growth patterns, but the contribution of the latter increased with age of ewe. Further experimental verification of the line differences in reproduction and lamb survival and study of their causes are needed. Nevertheless, these results indicate the promise of using indices of body weight and testis size to increase the efficiency of lamb production.
Sources of variation in myofibre number within and between litters of pigs
Authors: Dwyer C. M. , Stickland N. C. 
Published: September 2010

ABSTRACTA study of the determinants of inter- and intra-litter variation in muscle fibre number was carried out on five litters of Large White piglets. Fresh frozen, whole mid-belly sections ofm. semitendinosuswere stained to demonstrate acid-stable myosin adenosine triphosphatase activity. From these sections it was possible to identify which fibres had developed as primary and which as secondary fibres. Estimations of total muscle fibre number, total primary fibre number and ratio of secondary fibres to primary fibres were made for each animal. Results demonstrated that primary fibre number varied between litters (P<0·01) and was responsible for the variation in total muscle fibre number (P < 005) between litters since there was no significant variation in secondary: primary ratio. Within-litter differences in total fibre number could be attributed to both the secondary: primary ratio and primary fibre number, in almost equal contributions. However, when only the largest and smallest extremes of the litters were compared, variation in fibre number was due to the significant difference in the secondary: primary ratio (P<0·01). Taken as a whole, the results appear to show that primary fibre number is responsible for all the variation in muscle fibre number between litters, and also makes a significant contribution, with secondary: primary fibre ratio, to the variation present within a litter. The factors responsible for variations in primary and secondary fibre numbers are discussed.
A note on effects of lambing at one year and farm production level on the performance of prolific ewes
Authors: Omar I. , Jordan C. , Smith C. 
Published: September 2010

SUMMARYData from a large field trial comparing the performance of contemporary crossbred ewes from traditional and experimental prolific rams were used to study two factors, (1) the influence of lambing at 1 yr of age on subsequent ewe performance and (2) the effect of level of farm performance on the difference between the traditional and the prolific types. Neither effect was found to be important.
The nutrition of the veal calf 5. Comparison of two margarine fats
Authors: Roy J. H. B. , Stobo I. J. F. , Gaston Helen J. , Shotton Susan M. , Ganderton P. 
Published: September 2010

SUMMARY1. Twenty newborn Ayrshire male calves were used in a comparison of milk substitute diets containing two different margarine fats. The liquid diets were offered in two feeds daily ad libitum and the calves were slaughtered at 118 kg live weight.2. The two diets consisted of reconstituted spray-dried skim milk powder containing 200 g margarine fat/kg. One fat contained coconut and palm oils (CP) and the other coconut, palm and groundnut oils (CPG). The essential fatty acid content of margarine CP was less than half that of margarine CPG.3. The incidence of diarrhoea and of a high rectal temperature, and the severity of lung lesions tended to be higher, the incidence of nasal discharge was higher and daily dry-matter intake and liveweight gain were lower for calves given margarine CPG.4. Digestibility and balance trials were made at 1, 4 and 10 weeks of age. Nitrogen balance and apparent digestibility of the fat and other nutrients were not affected by the source of margarine, but the digestibility of dry matter and of fat was highest at 4 weeks of age, and of protein was lowest at 1 week of age. Apparent absorption of ash and calcium declined with age and absolute calcium retention was highest at 4 weeks. Total plasma lipids at 13 weeks of age did not differ between treatments.5. Age at slaughter was greater for calves given margarine CPG but dressed-carcass weight, killing-out percentage, perirenal fat deposition and kidney weight did not differ between treatments. Skin weight tended to be lower for the calves given margarine CPG. 6. It is suggested that the apparent increased susceptibility to infection of calves given margarine CPG was associated with its higher unsaturated fatty acid content.
A note on the utilization of the energy of the short-chain fatty acids in the fattening sheep
Authors: Lawrence P. R. , Thomas P. C. 
Published: September 2010

SUMMARYComplete C, N and energy balances were carried out on two mature sheep receiving a basal diet of pelleted hay plus continuous intraruminal infusions of either water or 400 kcal/day of propionic acid, butyric acid or a mixture of acetic acid and sodium acetate, for periods of 1 to 5 weeks. The efficiency of utilization for maintenance plus fattening of the basal diet and the basal diet supplemented with acetate, propionate or butyrate was 20·7 ± 1·0%, 28·3 ± 1·5%, 30·2 ± 0·5% and 31·3 ± 0·2%, respectively. The calculated efficiency of utilization for fattening (kf) of the infused energy sources was 69·9 ± 8·4%, 84·0 ± 3·4% and 86·0±2·0% for acetate, propionate and butyrate, respectively. In most instances kf did not vary with the length of the period of infusion but in one sheep there was an adverse response to the infusion of the acetate mixture, and during the first week of infusion kt was only 29·3%. During the third and fifth weeks of the infusion the corresponding values were 76±3% and 72±5%.
A note on the performance, carcass and muscle quality characteristics of pigs sired by Poland China and Large White boars
Authors: Chadwick J. P. , Smith W. C. 
Published: September 2010

SUMMARYTwo Poland China boars were mated with 12 Large White females and two Large White boars were used on the same number of females of similar background. In the post-weaning period a trial was conducted to compare the performance of purebred and crossbred progeny given a grower's diet on an ad libitum scale of feeding over the live-weight range 28 to 66 kg. Breed of boar did not influence litter size nor total litter weight at either birth or weaning. Poland China crosses compared with Large Whites grew more slowly to slaughter (10 %) but with equal efficiency of live-weight gain. Cross-breds had higher carcass yields (4 %), shorter (3 %) and deeper (2 %) carcasses, lower depths of mid-line and internal fat (11 %) and larger eye-muscle areas (22%). Breed of boar had little influence on joint proportions and no effect on carcass cut-out value. The eye muscles of crossbred carcasses were paler in colour and had higher transmission values but drip loss from the meat was not different.
The effects of temperature and type of floor on metabolic rate and effective critical temperature in groups of growing pigs
Authors: Verstegen M. W. A. , Van Der Hel W. 
Published: September 2010

SUMMARY1. Six experiments each with 2 groups of 9 pigs (9 castrated males and 9 females), 26 to 31 kg initial weight, were kept in a large indirect calorimeter equipped with two identical pig pens. In each pen nine animals were housed for periods of 6 to 8 weeks. The floors tested were: asphalt, straw bedding on asphalt (25 mm straw on asphalt), and concrete slats. Two experiments, each of four periods, were performed on each of the floors. The temperature in the calorimeter was changed in stepwise fashion by 2 to 3°C at intervals of 2 to 3 days. In periods 1 and 3 the temperature was decreased stepwise from 20·23°C to 5·8°C, and in periods 2 and 4 in the reverse order. Gaseous exchange was measured at each of the temperatures for 48 hr. Feeding level was kept constant at about 1160 kJ meta-bolizable energy/kg0·75.day.2. Heat production and energy balance per unit of feed intake were similar on all floors in the zone of thermoneutrality and the derived maintenance requirements were also similar with a mean value 438 kJ/kg0·75.3. The effective critical temperature of animals weighing 40 kg was 11*5 to 13°C on straw bedding, 14 to 15°C on asphalt and 19 to 20°C on concrete slats.4. At temperatures below the critical temperature heat production was increased. The increase in extra thermoregulatory heat production was on average 8·9 kJ/kg0·75 per °C below the effective critical temperature. Between the various floor types differences in this increase were noticed, but were not significant.5. Body-weight gains on asphalt and straw bedding were similar; on concrete slats the body-weight gain was significantly reduced.
The effect of different proportions of dried grass and concentrates in the diet on voluntary intake and performance of calves
Authors: McCullough T. A. 
Published: September 2010

SUMMARYComplete diets each containing (1) 0%, (2) 20%, (3) 40%, (4) 60% high-quality, (5) 20% and (6) 40% low-quality dried grass were given ad libitum to 48 British Friesian calves.The performance of the animals was studied over the stages of growth from 50 to 100 kg and 150 to 200 kg live weight. At each stage of growth the live-weight gain was similar on all treatments while the daily intake of dry matter was significantly affected by the treatments. Over the stage of growth from 50 to 100 kg live weight the intake of metabolizable energy was greatest on treatment 2 and lowest on treatment 4. The conversion ratio of metabolizable energy decreased with increasing levels and with both qualities of dried grass over the weight range 50 to 100 kg.When the calves reached 100 kg live weight, digestibility and N balance studies were carried out. The metabolizable energy (ME) expressed as a percentage of the gross energy decreased with increasing levels and with the lower quality of dried grass. Nitrogen retention was not significantly affected by treatment differences.The relationships of the voluntary intake of dry matter, ME intake and the conversion ratio of ME with the ME expressed as a percentage of gross energy over the lower live-weight range are also presented.
A note on the use of sarcomere length measurements as predictors of longitudinal growth in skeletal muscles
Authors: Hegarty P. V. J. 
Published: September 2010

SUMMARYSarcomere length and fibre diameter were measured in thebiceps brachiiandsternomastoideusmuscles from 35 male mice (5·3-38·0 g body weight). The fore-limbs of each animal were either folded or stretched maximally immediately post mortem and allowed to go into rigor mortis in that position. Unfixed isolated fibres were separated and the sarcomere length and fibre diameter measured. Sarcomere length remained unchanged with increasing body weight irrespective of whether the muscles were in the folded or stretched position. Sarcomere length was shorter in the foldedbiceps brachii(P< 0·01) andsternomastoideus(P< 0·05) than in the corresponding stretched muscles at all body weights. The results indicate that sarcomere length cannot be used as an indicator of the longitudinal growth of muscle, and that limb position during rigor development is a significant factor in altering sarcomere length.
The effect on sow productivity of oestrus suppression following a two-day lactation
Authors: Walker N. , Eddie S. M. 
Published: September 2010

SUMMARYSows which had lactated for 2 days were allocated either to a control group or to a group in which oestrus was delayed by the administration of 75 mg methallibure per day for 12 consecutive days, followed by an intramuscular injection of 1000 IU pregnant mare serum gonadotrophin. All sows were mated whenever they were receptive to a boar. The mean time to first mating for the control group of 12 sows was 7·3 days but the mean time to conception was 22·3 days. The corresponding figures for the 9 treated sows were 17·0 and 22·2 days. The treated sows had significantly (P < 0·025) larger litters than the control sows (11·7 v. 8·5). For those sows which conceived at the first post-weaning service, the delayed oestrus treatment increased litter size on average by more than four pigs per litter.
A note on the effect on puberty in gilts of exposure to a boar between 140 and 160 days of age
Authors: Walton J. S. 
Published: September 2010

ABSTRACTGroups of five Yorkshire ♂ x Landrace ♀ gilts were either exposed (BE) or not exposed (NE) to a mature boar commencing at 140, 147, 154 or 161 days of age. Each group of BE gilts was slaughtered 10 days after initial boar exposure, for examination of the reproductive tract, with one of the four NE groups killed at a corresponding age.NE gilts remained prepubertal throughout. Boar exposure induced ovulation in one gilt at 140 days, two gilts at 147 days, two gilts at 154 days and one gilt at 161 days. Boar exposure also increased uterine weight (P < 0·001). There were no effects of age either on the number of gilts ovulating or on uterine weight. There was a significant positive effect of body weight on uterine weight which was greater in BE gilts than in NE gilts. These results suggest that body weight may be a determinant of the response to boar exposure by gilts between 140 and 170 days of age.
Using goal programming in formulating rations for pregnant ewes
Authors: St C. Neal Heather D. , France J. , Treacher T. T. 
Published: September 2010

ABSTRACTModels are described which utilize goal programming to maximize hay intake in the formulation of rations for ewes in the last 6 weeks of pregnancy. By treating the energy or protein allowances (or both) as goals rather than restrictions, rations in addition to the linear programming (LP) optimal solution are generated. The approach offers a flexible alternative to the standard LP approach by providing additional rations with known deviations from the allowances. A set of guidelines is given to determine which of these rations could be tolerated when the nutritional requirements cannot be satisfied.
Effects of some anabolic agents on the growth, carcass and tissue composition of barley-fed entire and castrated male Friesian cattle
Authors: Fisher A. V. , Wood J. D. , Tas M. V. 
Published: September 2010

ABSTRACTThirty-eight barley-fed entire and castrated male Friesian calves were used to examine the effects of different implanted anabolic agents on growth and carcass and tissue composition. Entire males were implanted with trenbolone acetate plus hexoestrol alone or following an earlier implantation of zeranol, or with zeranol alone. Control bulls (no implant) and steers treated with trenbolone, acetate plus hexoestrol were also studied. The anabolic agents tended to increase growth rate in bulls, and caused an increase in fat deposition. Treated steers had more abdominal fat than all bulls, but did not have more carcass fat. However, the carcasses contained less saleable meat and had a lower retail value because of lower lean-to-bone ratio. There were no significant differences between any of the groups in the proportions of lipid and water in the lean tissue. Transporting the bulls resulted in a high pH and a dark colour in m. tongissimus. The results suggest that anabolic agents have small biological effects which directly modify the quantitative and qualitative meat production characteristics of bulls.
The response of store lambs to dietary supplements of fish meal 1. Effects of forage-to-concentrate ratio
Authors: Hassan S. A. , Bryant M. J. 
Published: September 2010

ABSTRACTForty-eight individually-penned lambs (mean live weight 31-4 kg) were offered one of four diets, to investigate response to a supplement of fish meal (0 and 100 g dry matter (DM) per kg M) given with diets of either 60: 40 or 40: 60 forage-to-concentrate ratio. Nitrogen (N) degradability in the rumen and fractional outflow rates of protein supplements were determined. The diets were formulated such that the lambs received about 3 or 9 g undegradable rumen N per kg DM. The diets were given daily to provide sufficient metabolizable energy for maintenance and 150 g gain, and were adjusted according to live weight at weekly intervals.Fish-meal supplementation improved daily growth over a 49-day period (P < 0·001) and enhanced N retention (P < 0·001). Live-weight gain was also marginally improved on the high-forage diets. (P < 0-05), but there was no protein supplement × forage-to-concentrate ratio interaction. Apparent digestibility of acid detergent fibre was improved by the fish-meal supplement on the high-concentrate diet.The four diets were also given to rumen-fistulated sheep. The high-concentrate diet was associated with a higher molar proportion of propionate (P < 0·05) and a lower proportion of acetate (P < 0·001). Rumen concentrations of ammonia tended to be maintained at higher levels throughout the day by the fish-meal supplement.