bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of exogenous bovine growth hormone and bromocriptine on growth, body development, fleece weight and plasma concentrations of growth hormone, insulin and prolactin in female lambs
Authors: Johnsson I. D. , Hart I. C. , Butler-Hogg B. W. 
Published: September 2010

ABSTRACTIn crossbred female lambs given a concentrate diet ad libitum between 8 and 20 weeks of age, daily subcutaneous injections of 0·1 mg bovine pituitary growth hormone (GH) per kg live weight increased daily live-weight gain (347 v. 284 g/day; P < 0·01; no. = 8), food conversion efficiency (3·94 v. 4·49 kg dry matter per kg gain; P < 0·01) and greasy fleece weight (1·49 v. 0·99 kg; P < 0·001). The increase (4·8 kg) in final live weight was due primarily to an increase in the non-carcass components of the body (3·5 kg), with little effect on carcass weight (1·3 kg). However, bovine GH treatment markedly increased the weights of lean tissue (11·4 v. 9·2 kg; P < 0·001) and bone (2·8 v. 2·4 kg; P < 0·001) and moderately reduced the weight of fat (7·0 v. 8·0 kg; P < 0·10) in the carcass. The bovine GH treatment raised plasma concentrations of immunoreactive GH within the physiological range for about 16 h each day and significantly increased mean plasma concentrations of insulin and prolactin. Daily injection of 1 mg bromocriptine had no effect on daily live-weight gain, food conversion efficiency or carcass composition. This treatment markedly reduced plasma concentrations of prolactin but also significantly reduced insulin concentrations. When given in combination with bovine GH, bromocriptine reduced the GH-induced stimulation of insulin concentration and tended to decrease the effects of GH on food conversion efficiency and growth. This interaction was significant only for the effects on greasy fleece and skin weights (P < 0·01).
Multibreed designs 3. Inter-breed relationships
Authors: Taylor C. S. , Hnizdo Eva 
Published: September 2010

ABSTRACTExperimental designs with optimal allocation of animals within and between breeds are given for investigating inter-breed relationships between different traits. Optimal designs are given for estimating the following between-breed parameters: the genetic regression with breeds random, the genetic correlation, the ratio of genetic standard deviations for two traits and also the comparison of regressions within and between breeds. As in the case of between-breed variation, these turn out to be multibreed designs with a few animals per breed and usually as many different breeds as possible. Formulae are given for obtaining optimal numbers and estimation errors for traits with intra- and inter-breed correlations lying within restricted ranges.If an exepriment with a multibreed design is to be effective, the optimum number of animals (or sires) per breed would normally lie between two and 10. If the optimum number per breed is much greater than 10, the experiment is unlikely to be worthwhile unless the total number of animals is large (at least several thousand).
Genetic improvement of litter size in pigs
Authors: Avalos E. , Smith C. 
Published: September 2010

ABSTRACTDespite the low heritability (0·1) for litter size in pigs, quite high rates of genetic improvement are predicted theoretically using conventional selection methods. The highest rates are predicted from schemes with rapid generation turnover (1 year) and with selection of both males and females at breeding age on a family selection index. This index would combine litter records (two on each relative) of the dam, her full sibs and half sibs, and of the sire's dam and his full sibs and half sibs. Annual rates of genetic change of up to half a pig per litter (a proportion 0-05 of the mean) are predicted. This rate is substantially greater than the proportional rates of genetic change possible for growth and carcass traits. These predictions are fairly insensitive to maternal and rearing environmental effects which may affect litter performance. High response rates are also predicted from two-stage selection of males, first on family index as before and then on progeny test of daughters in a large artificial insemination bred population. Intense screening in a large population for females with high litter records (hyperprolific females) can be an effective way to start an improvement programme for litter size. However, continuous screening of hyperprolific females is less effective because of the long time taken to generate enough descendants needed for the next round of intense selection. Despite the high rate of genetic change possible for litter size, omission of the trait from an index which includes growth and carcass traits would result in only small losses (proportionally less than 0·05) in economic improvement of general purpose stocks under United Kingdom market conditions. However, the losses would be higher (proportionally 0·10 to 0·18) in specialized dam stocks and inclusion of litter size in an index when selecting such stocks would be worthwhile.
Transferrins and milk production in dairy cattle
Authors: Ashton G. C. , Hewetson R. W. 
Published: September 2010

SUMMARYMilk and butterfat production data from eight herds of dairy cows in Australia for the years 1963 and 1964 were analyzed for relationship with serum transferrin type. In the 932 lactations considered D2/D2 cows produced 521 ± 152 lb of milk more than A/A cows and lactated 15·3 ± 7·8 days longer after correction for season. There was no difference in fat percentage of the milk. The production of A/D2 cows was also significantly higher than A/A cows, but less than D2/D2 cows. Allowing for differences in lactation length still left a significant difference between D2/D2 and A/A cows in milk yield.The best estimate of the effect of replacing aTfAby aTfD2gene, allowing for season, was 170 lb more milk (P<0·01) and 6·5 days longer lactation (P<0·05), whileTfD1did not differ fromTfAin either yield or lactation length.
The effect of length of journey by road to abattoir, resting and feeding before slaughter on carcass characteristics in bacon weight pigs
Authors: Cuthbertson A. , Pomeroy R. W. 
Published: September 2010

SUMMARYThree trials were conducted to investigate the effect of length of journey by road to the abattoir, resting and feeding before slaughter on carcass characteristics of pigs of about 200 lb live weight.Trial 1 investigated feeding or no feeding on the morning of slaughter, followed by a ½-hr or 8-hr journey by lorry to the abattoir with all pigs ending their journey and being killed at the same time. Ninety-six pigs were divided equally among the four treatments and the trial was repeated with a further 108 pigs. Measurements recorded on the live pigs and their carcasses included the live weight before the imposition of treatments, weight of liver, carcass and matured sides and the composition of a sample joint. Trial 2 studied lairaging overnight with food and water after a ½-hr or 8-hr journey to the abattoir compared with these journey lengths on the morning of slaughter. Eighty pigs were divided equally among the four treatments. Similar measurements to those in trial 1 were recorded. Trial 3 involved 49 pigs applied to each of three treatments, or 7-hr journey on the day of slaughter, with all pigs finishing their journey and being slaughtered at the same time.In trial 1, pigs which travelled for 8 hr before slaughter had carcasses averaging 0·9% less than those which travelled for ½ hr, regardless of whether or not they were fed. It could not be established where this loss occurred. Liver weights were greater for those pigs which were fed and was greatest for those pigs which were fed and had the ½-hr journey. Streak thickness was found to be decreased by feeding, but was not affected by the length of the journey. No effects of the treatments were found on pH or eye-muscle colour, but the ultimate pH of the pigs fed before the 8-hr journey was lower than for the other treatments. Trial 2 pigs showed no effect of the treatments on carcass weights. Liver weights were similar on all treatments except for the treatment involving 8-hr journey followed by lairage where the liver was about 220 g (16%) heavier. The ultimate pH value was lowest among pigs which travelled 8 hr on the morning of slaughter but was similar for pigs on the other treatments. In trial 3, loss of live weight tended to increase with increasing journey length. Pigs on the 7-hr journey treatment had about 90 g (6%) more liver than those on the shorter journeys. pH1 values increased with length of journey and the longer the journey the thinner tended to be the maximum shoulder fat thickness.From the differences in the results from the three trials, notably with carcass weight, it may be inferred that the behaviour and handling of pigs during the journey and during loading and unloading, may play an important part in determining the result of the length of the journey, resting and feeding. Further work is considered necessary to study such factors.
Effects of hormones and diets on performance and carcass characteristics of pigs during summer and winter
Authors: Hale O. M. , Johnson J. C. 
Published: September 2010

SUMMARYOne hundred and forty-four weanling Duroc barrows were individually fed to study effects of season (summer and winter), energy concentration of the diet (high and low), protein concentration (high and low), and orally administered hormones (none, diethylstilboestrol, and mefhyltestosterone) on performance and carcass characteristics of growing-finishing swine.In summer the rate of gain of pigs was 6% slower and yielded carcasses with 19% smaller loin-eye areas but 3% more lean cuts than in winter.Pigs fed on high-energy diets gained 13% faster, consumed 8% less feed daily and required 18% less feed per unit of weight gain than pigs fed on low-energy diets. Pigs fed on high-energy diets also had a dressing percentage 2·5 units higher and yielded carcasses 2% shorter, with 15% more backfat, than those fed on low-energy diets.Pigs fed on low-protein diets had a dressing percentage 1·6% higher and yielded carcasses with about 7% thicker backfat than pigs fed on high-protein diets. Dietary energy and protein concentrations interacted significantly in their effect on rate of gain. Pigs fed on low-energy, low-protein diets gained weight about 7% faster than pigs fed on low-energy, high-protein diets; however, pigs fed on high-energy, high-protein diets gained weight about 3% faster than pigs fed on high-energy, low-protein diets.The only significant effect of giving each pig about 2 mg of diethylstilboestrol (DES) per day was a 2% increase in weight of lean cuts. An average daily consumption of 20 mg methyltestosterone (MT) per pig decreased rate of gain, daily feed intake, dressing percentage and backfat thickness, but increased carcass length, area of the loin-eye and weight of lean cuts. Hormones and dietary energy levels interacted in their effects on rate of gain and feed efficiency. Pigs fed on low-energy diets with or without hormones gained weight at about the same rate, but high-energy diets increased rate of gain in pigs receiving no hormone or DES by about 17% and 21%, respectively, while having no effect in pigs receiving MT. Pigs fed on low-energy diets with MT required about 7% and 6% less feed per unit of gain than pigs fed on low-energy diets without hormone or with DES, respectively; whereas pigs fed on high-energy diets containing MT required about 10% and 14% more feed per unit of gain than did pigs fed on high-energy diets without hormone or with DES, respectively.
Factors affecting the interval between calving and conception in Hariana cattle
Authors: Dhillon J. S. , Acharya R. M. , Tiwana M. S. , Aggarwal S. C. 
Published: September 2010

SUMMARYEight hundred and ninety-eight records of the interval between calving and conception (service period) of 349 Hariana cows, the progeny of 79 sires, were analysed by fitting constants for the effects of year, month of calving, calving sequence, sex of the calf, weight of the cow at calving and weight of the calf at birth. The average service period was 272·7 days with a coefficient of variability of 50·7%.The service period was longest after the first calving. Animals calving in the months of February to August had a longer service period than those calving during the months of September to January. Heavier cows tended to have a shorter service period. Sex of the calf, calving sequence and birth weight of the calf did not affect this trait significantly.Heritability of service period estimated from the paternal half-sib correlation using repeated records was 0·06 ± 0·018 and repeatability was 0·250 ± 0·039. It seems likely therefore that a shortening of the service period may not be possible through direct selection.
A note on the fertility of rams exposed to high temperatures
Authors: Rathore A. K. 
Published: September 2010

SUMMARYFertility of rams was studied following their exposure to heat for 1 or 3 days in a hot room. Eight to 16 days later exposed rams showed significantly lower fertility as judged by lambing rate of ewes compared with unheated control rams. From 25 to 36 days after exposure treated rams were not significantly less fertile than controls. There were no significant differences in fertility between rams exposed 1 day or 3 days to heat.
Comparison of protein concentrations in diets given unchanged to pigs from 18 to 93 kg live weight
Authors: Lucas I. A. M. , Miles K. L. 
Published: September 2010

SUMMARYIn the national pig progeny test stations one diet is given up to about 55 kg live weight and another, with less protein, is given from then until slaughter. These diets were compared with four ‘single’ diets, similar in digestible-energy content, but containing either 15·6, 17·4, 18·7 or 22·1% crude protein, and each given unchanged from 18 to 93 kg live weight. There were twenty groups of one castrate and one gilt on each treatment.Pigs given the lowest protein levels had the poorest growth rates and feed conversion efficiency up to 57 kg live weight, but the best from 57 to 93 kg. Hence there were no differences in overall feed efficiency, and overall growth rate was only slightly less with the lowest protein level than with other treatments.Carcass leanness rose with protein level in the ‘single’ diets over the range 15·6·18·7% crude protein, but a further increase to 22·1% reduced leanness.Pigs given the progeny test diets had carcasses intermediate in composition to those of pigs on the ‘single’ diets with 17·4% and 18·7% protein.
Beef production from grass and silage with autumn-born calves. 2. The effects on the performance of cattle fed on silage of barley supplementation and of previous grazing intensity
Authors: Wllkinson J. M. , Prescott J. H. D. 
Published: September 2010

SUMMARY1. Two experiments are described in which the consequences of variation in grazing intensity were studied during the subsequent period of winter feeding from 12 months of age to slaughter at 18 months. The cattle were loose-housed and fed on silage ad libitum, together with allowances of rolled barley. Individual organic-matter intake was measured periodically, chromic oxide being used to estimate faecal output. The digestibility of the diet was estimated with stall-fed steers.2. Groups of 12 steers were grazed at different intensities over five-month periods, so that those grazed at the higher intensity were 38 and 16 kg lighter at the start of the 1966 and 1967 winter feeding periods respectively. They did not make significant compensatory growth over the subsequent winter feeding periods, although they had a significantly higher intake of feed organic matter per 100 kg live weight than the control steers.3. With supplements of 3·63 and 1·81 kg/head per day of barley, live-weight gains were 0·77 and 0·50 kg/head per dayin the first half of the winter, but in the second half, when barley allowances were raised to 4.54 and 2·72 kg/head per day, both groups gained weight at the same rate (0·94 kg/head per day).4. The higher level of barley feeding reduced silage intake by 0·4 kg OM/kg barley OM at all stages of the winter, and the additional 306 kg of barley was associated with the production of 21 kg more carcass weight at slaughter. This higher yield of carcass was reflected in a higher weight of fat in a three-rib sample joint.
A note on a tremor condition in adolescent pigs
Authors: Gedde-Dahl T. W. , Standal N. 
Published: September 2010

SUMMARYA temporary tremor condition in adolescent pigs is described which shows similarities with a tremor condition known to occur in young piglets. Growth and carcass traits were on average superior in affected pigs compared with unaffected litter-mates, paternal half-sibs and genetically unrelated pigs. Females were over-represented among the affected pigs which were born in large litters.
Some effects of alternating high and low levels of feed intake on the performance and composition of the growing pig
Authors: Fowler V. R. , Livingstone R. M. 
Published: September 2010

SUMMARYThree experiments were carried out in which the level of feed intake of pigs growing from approximately 30 to 90 kg was alternately raised and lowered, using different amplitudes and time-periods. Within each experiment, the total feed intake and the length of the experimental period were the same for all treatment-groups.The two amplitudes which were examined were 112%–88% and 125 %–75% of standard scales of feeding. The time-periods between switches to the alternate level were 1, 3, 7 or 14 days. The impact of the fluctuations in feed intake on overall performance and carcass composition was either trivial or small, and in no case exceeded 5% for any one measurement. It is concluded that fluctuations in feed intake occurring in practical situations will have only trivial effects on performance, provided that pigs receive similar amounts of feed in the same overall period of time.
Growth patterns of muscles of Merino sheep from birth to 517 days
Authors: Lohse C. L. , Moss F. P. , Butterfield R. M. 
Published: September 2010

SUMMARYEighty-two Merino sheep from birth to 517 days old were dissected into individual muscles. A system of overlapping growth coefficients was used to classify the growth patterns of 96 muscles and nine muscle groups. The relative size of muscles and groups at birth and one year are expressed as percentages of total half-carcass muscle weight.Some differences were noted from the previously recorded growth patterns of bovine muscles. The groups of muscles in the proximal part of the pelvic limb and those surrounding the spinal column were relatively faster-growing in sheep than in cattle.The patterns of the muscle groups are discussed relative to their function and it is shown that the patterns of growth of muscles within some groups are markedly different from the pattern of the whole group. This is most apparent in those groups with complex functions, and it is clear that anatomical grouping of muscles and functional grouping of muscles will be similar only in those regions of the body with relatively simple actions.
Energy and protein supplements for straw-based winter diets for suckler cows
Authors: Ball C. , Broadbent P. J. , Dodsworth T. L. 
Published: September 2010

SUMMARYA variety of energy and protein supplements for winter diets based on barley straw were tested in experiments carried out over three years with spring-calving suckler cows. All the supplements resulted in satisfactory calf weaning weights and cow performance but there were indications that a low level (2·3 kg) of barley plus 68 g urea adversely affected the birth weights of calves and their performance from birth to turnout.
A note on the effects of changing the concentration of protein in the diet offered to fattening beef cattle
Authors: Kay M. , Macdearmid A. 
Published: September 2010

SUMMARYTwo growth trials were carried out with a total of 112 British Friesian steers to examine the effects of offering all-concentrate diets containing different concentrations of crude protein. In Experiment 1 the steers were offered a diet containing either 17·5 % (H), 14·5 % (M) or 11·5 % (L) crude protein in the dry matter from 100 to 250 kg live weight and changed to diet M, L or one containing 9·5% crude protein in the dry matter (VL) between 250 kg and slaughter, so that the protein content of the diet offered to each steer was lowered by between 2 % and 3 % at 250 kg. In Experiment 2 the diets used were H and M between 100 and 250 kg and M and L between 250 kg and slaughter. Some steers in Experiment 2 were offered the same diet (M) throughout the experiment. Steers offered diet L between 100 and 250 kg ate less feed than steers given diet H and grew at a slower rate than steers given either diet H or M. Those steers given diet VL between 250 and 350 kg grew more slowly than those given diet M or L. For most steers a considerable saving in supplementary protein could be achieved by adopting an ML sequence rather than an HM or MM sequence when formulating dietary supplements.
Rearing of dairy cattle 6. The effect of length of grazing rotation on animal and herbage production in a grazing system for calves and heifers
Authors: Leaver J. D. 
Published: September 2010

SUMMARYA rigid system of grazing management was examined for 2 years using rotations of fixed length. Rotations of 21 and 35 days were compared at low (3 calves+ 3 heifers/ha) and high (4 calves+ 4 heifers/ha) stocking rates. The calves and heifers grazed the paddocks on a leader/follower basis.Average growth rates for the 21- and 35-day rotations were respectively 0·75 and 0·78 for calves and 0·78 and 0·83 kg/day for heifers, but these differences were not significant. The 35-day rotation produced 6% more live-weight gain and 4% more herbage dry matter/ha than the 21-day rotation. The high stocking rate produced 14% more live-weight gain but 3% less herbage dry matter/ha than the low stocking rate. The total percentage utilization of herbage dry matter for the whole season was similar for 35- and 21-day rotations, averaging 90%. There were no significant interactions between length of rotation and stocking rate.
Effects of using rations of reduced energy concentration for intensively reared beef cattle from 250 kg live weight to slaughter
Authors: Broadbent P. J. , Ball C. , Dodsworth T. L. 
Published: September 2010

SUMMARY1. Two experiments are described in which castrated Ayrshire cattle were reared on a conventional all-concentrate diet to 250 kg live weight. In Experiment 1 the effect of feeding a 1: 1 mixture (by weight) of barley and wet distiller's grains (WDG) from 250 to 408 kg live weight was examined. In Experiment 2 swedes and grass silage were offered in addition to WDG and barley during the growth phase from 250 kg live weight to slaughter. In both experiments a control group was fed an all-concentrate diet.2. The introduction of WDG to the diet (Experiment 1) caused a significantly lower daily live-weight gain (P < 0·01) and an increase i n time to slaughter (P < 0·01). Carcasses from the control and treated animals were similar in weight, conformation and composition. There were no differences in growth rates in Experiment 2. The treated animals were heavier (P < 0·01) and older at slaughter (P < 0·001) than those in the control group and they produced heavier carcasses (P < 0·05). The carcasses were similar in composition but some differences in conformation occurred. These effects were the consequence of selecting animals for slaughter on the basis of equal finish (i.e. the ratio of muscle plus fat to bone assessed subjectively).3. The effect of reducing the dietary energy concentration appears t o be smaller with cattle over 250 kg live weight than with younger, lighter cattle. The results, which are discussed in economic terms, suggest that castrated Ayrshire cattle reared on all-concentrate diets should be changed to a diet of lower energy concentration using cheaper feed sources at 250 kg live weight.