bluuebunny/crossref_metadata_2025_split huggingface dataset:
A note on the effect of exposure to a boar on the development of the reproductive system of immature gilts
Authors: Walton J. S. 
Published: September 2010

ABSTRACTEight groups of six Yorkshire gilts were either exposed (BE) or not exposed (NE) to a mature boar at 160 days of age. These groups of gilts were slaughtered at 160, 165, 170 and 180 days of age for examination of their reproductive tracts.NE gilts remained pre-pubertal from 160 to 180 days, with uterine weights of 121·6 g and 148·0 g respectively. Boar exposure induced ovulation in three out of five gilts by day 170 and in five out of six gilts by day 180. Uterine weight increased in BE gilts from 121·6 g at 160 days to 343·6 g, 298·0 g and 535·6 g by days 165, 170 and 180 respectively. This was accompanied by an increase in the number of large ovarian follicles (≤ 6 mm in diameter) from 0 at 160 days to 9·0 at 165 and 4·2 at 170 days.These results confirm the potent stimulatory effect of boar exposure on puberty in gilts and suggest the use of ovarian status and uterine weight at slaughter 10 days after stimulation as a reliable indicator of the response of the pre-pubertal gilt to environmental change.
A new approach to the mathematical formulation of lactation curves
Authors: Morant S. V. , Gnanasakthy A. 
Published: September 2010

ABSTRACTSix alternative lactation curves were derived by considering the proportional rates of change in milk yield during lactation. Experimental data showed that rates of change do not necessarily fall to a constant value in mid and late lactation. This accounts for the systematic lack of fit reported by several authors using the derivative of the incomplete gamma function, whose second derivative has a horizontal asymptote. Curves whose derivatives are not restricted in this way described patterns of milk yield in first to third lactation animals more closely. Some statistical properties of their parameters have been examined. The curve loge (y) = a - bt'(1 + kt') + ct'2 + d/t, where t is days since calving, t' = t – 150, A: is a constnat and a, b, c and d are parameters to be estimated, is recommended. This curve was also fitted to yields of milk fat, protein and lactose.
A deterministic model for the optimization of dairy cattle breeding based on BLUP breeding value estimates
Authors: Meuwissen T. H. E. 
Published: September 2010

ABSTRACTA deterministic model was developed to examine the optimization of open nucleus breeding schemes in order to maximize the rate of genetic response in dairy cattle. By changing the parameters, the model was able to simulate both a closed nucleus and a progeny testing scheme. The model implicitly optimized the generation interval and the selection across tiers by means of truncation across age classes and tiers respectively. The effects of size of the progeny test group and the nucleus size were assessed by comparing alternative plans. It is possible to optimize a breeding plan given the reproduction rates of the animals, the availability of different sources of information, the age distribution of the animals (survival rates) and the phenotypic and genetic parameters of the trait.The steady state selection response was assessed by calculating the genetic progress year after year until it stabilized. The genetic gain was corrected for the effects of reduced variances due to previous selections and increased variances due to genetic differences between parental age classes.In an example, the model was used to predict the improvement in milk yield in a closed artificial insemination breeding scheme. The genetic gain of a conventional progeny testing scheme was about one-third lower than the genetic gain of the optimized breeding plan. The variance reduction due to selection decreased the steady state genetic gain by a factor 0·3
Effects of recombinant DNA-derived bovine somatotropin on growth, carcass characteristics and meat quality in lambs from three breeds
Authors: Sinnett-Smith P. A. , Woolliams J. A. , Warriss P. D. , Enser M. 
Published: September 2010

ABSTRACTPurebred lambs from three breeds (East Friesland, Oxford and Texel) were fed to appetite and treated with recombinant DNA-derived bovine somatotropin (BST) at 0·05, 0·10 or 0·20 mg/kg per day or a placebo between 19 and 27 weeks of age.BST maintained growth over the later stages of treatment but did not affect average daily live-weight gain over the whole treatment period. Food intake was decreased and food conversion efficiency was improved by BST treatment. However, carcass weight and killing-out proportion were decreased by BST treatment in all breeds. Consistent breed differences were observed. Oxford lambs had higher live weights and carcass weights than the other breeds but no breed × treatment interactions were apparent. Ultrasonic backfat depth (mean of measurements at 13th rib and 3rd lumbar vertebra) was reduced by BST treatment in the Oxford (the fattest) and Texel lambs but not in the East Frieslands (the leanest). Ultrasonic muscle depth was not affected by BST; East Friesland lambs had considerably smaller muscle depth than the other breeds.In the loin joint, BST decreased fat cover and subcutaneous fat proportion and increased longissimus dorsi proportion. There were also marked breed differences with Oxfords fatter than the other breeds. BST treatment did not affect any of the meat quality indicators but some differences between breeds were apparent in ultimate pH and colour of the muscle. Fatty acid composition of the subcutaneous fat was affected by breed but not by BST. East Friesland lambs had higher concentrations of unsaturated and branched chain fatty acids than the other breeds.A mammogenic response (increased mammary development and some secretory activity) to BST was observed in some female East Friesland and Texel lambs but not in Oxford lambs.
Low glucosinolate full-fat rapeseed meal in the diets of early-weaned piglets
Authors: Gill B. P. , Taylor A. G. 
Published: September 2010

ABSTRACTThe potential of using low glucosinolate full-fat rapeseed meal (FFR) in the diets of early-weaned piglets was investigated in this experiment. FFR (containing 17 (xmol total glucosinolates and 2·8 mg erucic acid per g of whole seed) was used on an isonitrogenous basis at either 200 g<kg or 400 g<kg to replace full-fat soya-bean meal. Four replicates of three contemporary pen groups of 10 piglets weaned between 3 and 4 weeks of age were randomly allocated at a mean initial weight of 8·41 (s.e. 1·105) kg to the three dietary treatments. The experimental diets were given for 3 weeks. Inclusion of FFR significantly depressed food intake, daily live-weight gain and food conversion. There were no significant differences between the performance of piglets given either 200 or 400 g FFR per kg. Intakes of the diets containing FFR per unit of metabolic body weight as a proportion of the control diet decreased from about 0·85 to 0·75 from the 1st to the last week of the feeding period. This suggested that the acceptability of diets containing FFR decreased with time, possibly due to the presence of unpalatable and perhaps antinutritive factors which may include glucosinolates although present at relatively low concentrations. It was concluded that the feeding value of FFR would need to be improved by development of oilseed rape varieties with much lower levels of glucosinolates.
The effect of hexoestrol implants on sucking and weaned lambs fattened on farms in the north-east of Scotland
Authors: Preston T. R. , Greenhalgh Isoline , MacLeod N. A. 
Published: September 2010

1. 768 lambs on fourteen farms in the north-east of Scotland were divided into a control group and groups receiving two 5 mg., three 5 mg., two 7·5 mg., and one 15 mg. pellet of hexoestrol.2. On every farm the mean rate of live-weight gain of the treated lambs was greater than that of the controls.3. There appeared to be very little difference between implantations of two 5 mg., three 5 mg. and two 7·5 mg. pellets of hexoestrol but on four farms where a direct comparison was made one 15 mg. pellet was slightly inferior to three 5 mg. pellets.
The effect of plane of nutrition during rearing on growth, production, reproduction and health of dairy cattle. I. Growth to 24 months
Authors: Crichton J. A. , Aitken J. N. , Boyne A. W. 
Published: September 2010

1. Eighteen pairs of one-egg and 6 pairs of two-egg twin calves were used in a balanced incomplete block design to examine four systems of rearing: (1) a continuous high plane of nutrition from birth to first calving (HH); (2) a high plane for the first 44 weeks followed by a low plane until 2 months before calving (HL); (3) a continuous low plane until 2 months before calving (LL); and (4) a low plane to 44 weeks followed by a high plane to first calving (LH). All animals were fed on a high plane during the two months before calving.2. Mean daily consumptions of DM, TDN, S.E. and DCP are given and the net energy intakes compared with a recently recommended standard.3. At 44, 80 and 104 weeks of age there were highly significant differences between the groups in all weights and measurements due to treatment. Low-plane feeding retarded the growth of the skeleton to only a limited extent as compared with live-weight. After the changeover, animals on the HL system lost much of the advantage in body measurements they had gained over those fed on a continuous low plane.4. All groups reached sexual maturity at the same stage of physical development but at different ages. The HL animals were the slowest to attain maturity indicating that as with growth the changeover from a high plane to a low plane of nutrition had had an adverse effect.5. Low-plane animals on poor hill pasture made better growth than their mates on good arable pasture. Evidence is presented, however, to show that part of this greater growth in live-weight was due to increased ‘fill’.
A comparison of whole milk with buttermilk in the rearing of calves for veal. 2. Slaughter and carcass composition data
Authors: Barton R. A. , Kirton A. H. 
Published: September 2010

1. Two groups of Friesian calves, one group of 10 reared on whole milk and the other group of 9 changed gradually from whole milk at 21 days of age to a full diet of reconstituted buttermilk powder at 29 days of age, were slaughtered at a live-weight of approximately 203 1b. Data obtained at slaughter showed a highly significantly heavier weight of omental fat from the calves of the whole milk group, and a significant difference in the weight of the unemptied intestinal tract in favour of the buttermilk group.2. One side of each carcass was dissected by anatomical joints into the primary tissues; bone, muscle, fat, and tendon and waste. The absolute proportional weight of the dissectible fatty tissues and the weight of kidney and channel (pelvic) fat were statistically highly significantly heavier in the carcass sides of the calves reared on whole milk. The percentage of muscular tissue in the sides of the buttermilk reared calves was significantly higher than for the sides in the other group.3. The chemical composition of the dissected muscular tissue revealed highly significant differences in fat (ether extract) and a significant difference in water percentage in favour of the carcass sides of the calves reared on whole milk.4. The chemical composition of the dissected fatty tissue showed statistically highly significant differences in favour of the calves reared on whole milk for the items: water weight and percentage, fat weight and percentage, protein weight, and ash weight. The buttermilk group had in their dissectible fatty tissue a highly significantly greater proportion of water and protein.5. The dissectible components of the individual joints showed: significantly heavier weight of fatty tissue from the leg, loin, pelvis, 9–10–11 rib cut, thorax, and shoulder of the left sides of the calves reared on whole milk. The weights of the dissectible muscular tissue of the loin and the rib cut were significantly heavier for the buttermilk-reared calves.6. Cutting-out data on a limited number of sides showed no consistent differences between groups.7. The meat trade did not differentiate against the buttermilk-fed calves despite their lower fat content. The high muscular tissue content at 65–68% makes veal a very desirable product.
Copper sulphate as a growth stimulant for pigs: effect of level and purity
Authors: Lucas I. A. M. , Livingstone R. M. , McDonald I. 
Published: September 2010

Two 2 × 4 factorial experiments each involved 8 litters of 8 pigs, one pig from each litter being allocated to each treatment. Diets containing supplements of a commercial grade of copper sulphate were compared with others containing Analar (Experiment 1) or micro-analytical reagent grade copper sulphate (Experiment 2). Four levels of each of two grades of CuSO4.5H2O, providing 16, 62, 125 or 250 p.p.m. Cu in the diets, were given in each experiment.The pigs were put on experiment at 8—9 weeks of age and most were slaughtered as their individual weights reached about 200 lb. The exceptions were 4 litters in Experiment 1 which were taken off experiment at that weight but not slaughtered. The pigs were fed in individual compartments, meal allowances being determined from a fixed scale based on live-weight.Purity of copper sulphate did not affect growth rate, feed conversion efficiency or carcass measurements in either experiment.Response to level of copper sulphate between about 45 and 100 lb. liveweight differed somewhat between experiments. In Experiment 1 pigs receiving 125 or 250 p.p.m. in the diet grew 4 or 9% faster and had better feed conversion efficiencies than those receiving 16 or 62 p.p.m. Cu. In Experiment 2, pigs receiving 62, 125 or 250 p.p.m. Cu all grew about 4–5% faster and had 1–5 % better feed conversion efficiencies than those receiving 16 p.p.m. Cu, but the effect on feed conversion efficiency was not statistically significant.Increase in copper sulphate above the trace level supplying 16 p.p.m. Cu in the diet had no effect on growth rate or feed conversion efficiency between 100 and 202 lb. live-weight or on killing-out percentage or carcass measurements.Comparison of the results with those from a previous experiment showed that in pigs fed according to a fixed scale the greatest consistent increases in growth rate and feed conversion efficiency have occurred with copper sulphate as 0·1% of the diet, giving 250 p.p.m. Cu. This supplement has only improved performance between 100 and 200 lb. live-weight in one experiment out of five.
The yields of cuts from Wiltshire bacon sides in relation to length and other carcass measurements
Authors: Harrington G. , Pomeroy R. W. 
Published: September 2010

1. Judges' scores for the ‘proportion of cuts’ of bacon sides were related to the length and to the ratio of the length and depth of the sides, but not to the weight of the fore-end.2. In two investigations involving six hundred and eighty sides of bacon, length showed little relation to the yields of the major wholesale cuts or to measures of value based upon them, although in one analysis longer sides tended to have lighter fore-ends. Fatter sides tended to be heavier in the back and lighter in the fore-end and gammons than leaner sides of the same weight.
Nutritional factors affecting lean meat production in cutting pigs
Authors: Bellis D. B. , Taylor J. 
Published: September 2010

A series of trials were designed to determine the slaughter weight of cutting pigs at which lean meat production is most economical, and to investigate nutritional factors which affect lean meat onput in cutting pigs of about 260 lb. live-weight. The trials involved about 1100 pigs and ad lib. feeding was adopted from weaning to slaughter.In the first trial, pigs were fed on various diets to 300 lb. live-weight. The diets differed in the amount of protein fed during the 90–180 lb. growth period, and the most economic growth was made by feeding a high protein (17 %) diet to 140 lb., or a medium protein (14 %) diet to 180 lb. followed by a cereal-mineral diet thereafter to 300 lb.Animals were slaughtered and dissected at various live-weights between 90 and 300 lb. and it was found that killing-our percentage, the percentages of usable meat (lean plus fat) and of fat, increased with carcass weight. The increase in fat deposition was mainly at the expense of the non-edible parts of the carcass. Onput of lean and increase in area of eye muscle occurred throughout the range.Total food requirements, expressed as pounds of food, calories of gross energy or pounds of protein, per pound of usable meat produced decreased as slaughter weight increased. The cost of food required to produce a given quantity of lean meat was least when pigs were slaughtered between 240 and 260 lb. when the commercial value of the remainder of the carcass was taken into account.The second trial investigated the effect of two levels of protein and mineral supplementation of cereals during the 140–260 lb. growth period of heavy pigs. Correct mineral supplementation of cereals was essential because, although lean meat production was not increased, the cost of food required to produce it was less. The lower protein diet had no effect on growth or carcass composition, but the higher protein diet increased the lean meat content of carcasses and decreased the amount of food required to produce it. The production of the extra lean meat, however, was not economical because of the cost of the high protein diet.The third trial showed that replacement of barley by wheat during the 140–260 lb. growth period led to carcasses having less lean meat and to higher feed requirements. This is probably connected with the high energy content of wheat as compared to barley.
Further observations on the relative influence of birth weight and creep-feed consumption on the 3- and 8-week weights of sucking pigs
Authors: Lodge G. A. , McDonald I. , MacPherson R. M. 
Published: September 2010

1. Data from the first 3 litters of each of 21 Wessex Saddleback sows were analysed on within-Utter, between-litter/within-sow and between-litter/ between-sow bases.2. There were highly significant differences between sows in the mean weight of their pigs at birth, 3 and 8 weeks of age; between litters of the same sow there were no significant differences at birth or 8 weeks but pigs in third litters were significantly lighter than those of the first and second Utters at 3 weeks of age. There was a significant increase in number born but not in number weaned from first to third litters.3. Within litters, the variation in 3-week weight accounted for by variation in birth weight was 30% in first litters, 48% in second litters and 45% in third; respective relationships between birth weight and 8-week weight were 14, 27 and 26%. Between litters of the same sow, differences in mean birth weight accounted for 50 % of the difference which occurred in 3-week weight and for 26 % of the difference in 8-week weight. Differences in mean creep-feed consumption accounted for 18% and differences in mean 3-week weight for 44% of the differences which occurred in weight at weaning. Between litters of different sows, the variation in birth weight accounted for 48% of the variation in 3-week weight, and 8% of the variation in 8-week weight. Differences in creep-feed consumption accounted for 36% and differences in 3-week weight accounted for 26 % of the difference in weight at weaning.4. Season of birth had some effect on weaning weight due in part to an effect on creep-feed consumption. There was a negative correlation between birth weight and mortality and a positive correlation between mortality and Utter size.
Further studies of hexoestrol implantation of Blackface wether lambs
Authors: Armstrong R. H. , Cameron A. E. 
Published: September 2010

1. In the summer of 1958, 15 mg. of hexoestrol was administered to Blackface wether lambs in one of the following ways; 5 mg. before weaning followed by two 5 mg. tablets at weaning, three 5 mg. tablets at weaning, and thirdly a single 15 mg. tablet at weaning. In a further series of experiments in 1959 the effect of both raising the pre-weaning implantation to 10 mg., and the total hexoestrol dosage to 20 mg. was studied.2. Suckled lambs implanted with 5 mg. of hexoestrol at the milk clip gained significantly more in live-weight (18%) up to weaning in 1958 than did untreated lambs; in 1959 the difference was only 11%.3. Between weaning and the end of the trial all treatments with the exception of that in which hexoestrol dosage was raised to 20 mg. showed a very highly significant increase in live-weight gain over untreated lambs, the increases ranging from 26 % to 54%.4. In neither year was the overall gain in live-weight from pre-weaning to the end of the trial significantly increased by implanting part of the hexoestrol dose prior to weaning.5. Live-weight gain of the lambs was not significantly increased when three 5 mg. tablets of hexoestrol replaced a single 15 mg. tablet.6. The implanting of lambs with 20 mg. hexoestrol failed to give a response superior to that obtained with 15 mg. hexoestrol.7. Each group of lambs receiving hexoestrol treatment showed an increased average carcass weight.
Further observations on the effects of growth checks in pigs of 50 lb. live-weight and over
Authors: Lucas I. A. M. , Livingstone R. M. , McDonald I. 
Published: September 2010

Forty-eight individually-fed Large White pigs, initially 10 weeks of age, were used to test the effects of growth checks induced by severe restriction of feed intake. The checks were imposed at 50 lb. or 100 lb. live-weight and lasted for 5 weeks, during which live-weight gains averaged only 1·6 lb. and 4·1 lb. per pig, respectively. The daily feed allowances of the unchecked controls and of other pigs while not on check were according to a fixed scale based on live-weight. All pigs were slaughtered as their individual weights reached 200 lb. and a number of measurements were made on the carcasses.Excluding the period of the check, efficiency of feed conversion and rate of gain were better for pigs checked at 50 lb. than for the controls. The difference in age at a given weight caused by the check was narrowed by about 6 days at the end of the experiment. Indications of a similar compensation in growth of pigs checked at 100 lb. were mostly explained by the rapid growth of these pigs before 100 lb. and by the sudden increase i n their weight at the end of the check period which was probably due to increased gut fill.A check at 50 lb. or 100 lb. did not affect either the specific gravity of the carcass, which was taken as an indication of the overall proportion of lean to fat, the area of ‘eye’ muscle, the depth of backfat over the shoulder, the thickness of streak or the Danish ‘slight of lean’ measurement, but the check at 50 lb. increased the thickness of fat at position (1) over the ‘eye’ muscle. Both checks increased the minimum thickness of back fat in females but not in castrates and reduced the average rump fat in castrates but not in females. It was concluded that the checks did not affect carcass composition although they probably caused changes in the distribution of the backfat.