bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of slaughter weight upon the growth and carcass characteristics of rabbits fed diets of different dietary metabolizable energy concentrations
Authors: Butcher Catherine , Bryant M. J. , Owen E. , Leach I. , Machin D. H. 
Published: September 2010

ABSTRACTEighteen male and 18 female weaned rabbits were randomly allocated to two diets formulated to give energy concentrations of 8 (LE) and 10 (HE) MJ metabolizable energy per kg dry matter and three target slaughter weights (1·5, 2·25 and 3·0 kg live weight) to give a 2 × 2 × 3 factorial design with three replicates. Voluntary food intake and live-weight gain were monitored and the carcasses chemically analysed. The metabolizable energy concentrations of the diets were determined by balance and found to be 9·87 and 6·84 MJ/kg dry matter for diets HE and LE respectively.Rabbits fed the LE diet consumed more dry matter (P < 0·001) and metabolizable energy (P < 0·01) in total, but grew more slowly than those fed the HE diet (P < 0·001). A diet × slaughter weight interaction occurred (P < 0·01); rabbits of the LE–3 kg treatment took longer to reach target weight as a result of a flattening of their growth curve.Rabbits fed the LE diet had lower killing-out proportions (P < 0·05), heavier gut weights (P < 0·05) and gut contents (P < 0·05), but lighter livers than those fed the HE diet. Killing-out proportion progressively increased with increasing slaughter weight. External offal weight as a proportion of live weight tended to increase while internal offal weight as a proportion of live weight tended to decrease as slaughter weight increased. The carcasses of rabbits slaughtered at 3 kg had lower moisture contents (P < 0·001), greater fat contents (P < 0·001) and lower ash contents (P < 0·05) than other slaughter treatments. A significant diet × slaughter weight interaction occurred in fat content, with rabbits of the LE–3 kg treatment having proportionally more fat. With age at slaughter as a covariate, rabbits fed the HE diet had proportionally more fat (P < 0·05).
A note comparing lambs from three crossing-ram breeds
Authors: Cameron N. D. , Deeble F. K. 
Published: September 2010

ABSTRACTSixty-nine rams of three crossing-ram breeds were mated on 11 farms over 3 years to produce crossbred ewes for a large field trial. Scottish Blackface and Welsh Mountain ewes mated to Bluefaced Leicester rams had larger litters at weaning than those mated to Border Leicester and the Animal Breeding Research Organisation's Damline rams. The crossbred Bluefaced Leicester lambs were heavier than the other crossbred lambs at both birth and weaning.
The dependence of lean carcass composition on carcass fat, as assessed by multivariate shape/size methods
Authors: Seebeck R. M. 
Published: September 2010

ABSTRACTThe relationship between the composition of the fat-free carcass and carcass fatness was studied by considering the relationship as one between two shape vectors, with the effect of size removed, using an extension of the multivariate linear least squares technique for studying multivariate allometry.In two sets of data, one of dressed carcasses of cattle and the other of empty carcasses of lambs, the composition of the fat-free carcass (in terms of protein, water and ash) was significantly related to carcass fatness (P< 0·10 andP< 0·05 respectively). The consequences of this relationship to the study of the chemical composition of carcasses are discussed.Examination of the relationship in more detail showed that the fatter carcasses were those with more protein and less water in their fat-free carcass, in both sets of data, and with more ash in the empty carcasses of lambs.
A note on supplementing whole oat grain with molasses, urea, minerals and vitamins
Authors: Bogdanovic B. 
Published: September 2010

ABSTRACTTwo rations were prepared for sheep in which whole oat grain was mixed with molasses, urea, minerals and vitamins. Chemical analysis showed that the minerals had adhered to the grain and that there was little loss of minerals after one year of storage. The diets were readily consumed by sheep.
Growth and carcass traits of bulls and veal calves of continental cattle breeds 1. Growth and food conversion efficiency
Authors: Khalil H. , Pirchner F. 
Published: September 2010

ABSTRACTBetween six and 11 twin pairs each of the breeds Braunvieh (BV), Fleckvieh (FV), Grauvieh (GV), Pinzgauer (Pi) and Friesians (Fr) were either treated uniformly or separated and fattened to veal or to yearling bull stage. The aim of the experiment was the comparison of Central European breeds and to investigate genotype × rearing system interaction both within and between breeds. Veal calves were slaughtered at about 120 to 150 kg live weight (proportionately about 0·13 of estimated mature weight of bulls) and yearling bulls at 410 to 460 kg live weight, corresponding to proportionately 0·38 of estimated mature weight. In general, the dual-purpose breeds had higher growth rates both absolute (AGR) and relative (RGR) and better food conversion ratios (FCR) than the dairy breed, Friesian, and this was true irrespective of whether correlations were made to constant age, weight, maturity (equal proportion of adult weight) or carcass fatness. However, the early-weaned Friesian calves grew fastest in the early phase of the growing period and this probably reflected their superior appetite.Interactions between breeds and rearing system (bull v. veal) were significant for RGR and for maturity-corrected FCR which was mainly caused by shifting of the positions of BV and Pi.The pooled genetic correlations between performance in the different fattening categories were considerably below unity. The twin-pair correlations indicated high heritabilities which are biased by contributions from dominance and maternal environment. While in data corrected to comparable maturity, AGR and RGR were highly positively correlated, their correlation became negative in agecorrected data. The correlations with FCR displayed an equivalent change with sign reversed. The correlations between wither height and heart girth with AGR were positive for age-corrected data but negative or barely positive, respectively, for data corrected to equal maturity. Again, FCR behaved similarly but with sign reversed.
Growth and carcass traits of bulls and veal calves of continental cattle breeds 2. Carcass composition
Authors: El-Hakim A. , Eichinger H. , Pirchner F. 
Published: September 2010

ABSTRACTSibs of five to 11 twin pairs each of five breeds were either slaughtered as veal or as yearling bulls. Highly significant breed differences were evident in the carcass tissue proportions which could be explained on the basis of differences in the physiology of dairy and dual-purpose animals, the former depositing more fat and more bone than dual-purpose breeds. Among the dual-purpose breeds the carcasses of the Pinzgauer (Pi) tended to rank between the carcasses of the Fleckvieh (FV), Braunvieh (BV), Grauvieh (GV) and those of the Friesian (Fr).The dual-purpose breeds FV, BV, GV had more meat in the hindquarter and in the shoulder than the FR while these in turn had more meat in the brisket and in the flank and shank muscles. Again the Pi group tended to rank between the aforementioned groups.Within breeds, large differences between twin pairs indicated high heritabilities for carcass tissue proportions and ratios. The heritability of commercial cut proportions was fairly high but the genetic variance was small, the genetic coefficient of variation being less than 0-02. The different degrees of sexual maturity and of carcass maturity also caused differences in the distribution of meat in the carcasses of young male animals.Significant mean squares for interactions between treatments and breeds, and genetic correlations of less than unity between performance of twin genotypes in veal and in bulls, indicated age and/or rearing system by genotype interactions between and within breeds for various slaughter traits.Phenotypic correlations between various slaughter traits were low except where part-whole relationships were involved. It is suggested that slaughter at comparable maturity in the respective treatments was the cause of the weak connection between the traits.
Effects of age and its relationship with body size on reproductive performance in Scottish Blackface ewes
Authors: Gunn R. G. , Doney J. M. , Smith W. F. , Sim D. A. 
Published: September 2010

ABSTRACTOn a hill farm, the reproductive performance of Scottish Blackface ewes increases annually with increasing age up to 6 years and is positively related to pre-mating live weight. A group of Scottish Blackface ewe lambs was, from 5 months of age, preferentially managed over a 2-year period to accelerate the achievement of mature size, in order to study the relative importance of age and size to reproductive performance. Ovulation rate and early embryo mortality of these ewes at 31 months of age were compared with those of adult ewes of similar body size and condition at 79 months of age which had been reared conventionally in the same hill flock. Two comparisons were made, one between different age groups in the same year and the other retrospectively between different ages of the same age group. In the first comparison, the adult ewes had a slightly greater reproductive response which suggested a small effect of age per se but there was also the possibility of a genetic difference. In the second comparison, there was no difference in ovulation rate or potential lambing rate per pregnant ewe, but a trend towards greater wastage of twin-shed ova in the heavier and fatter younger ewes again suggested a small effect of age. At both ages, however, these ewes performed close to their adult genetic potential which suggested that the treatment of the young ewes was sufficient to overcome most of the limitations associated with age or size. Reproductive performance normally associated with young animals is therefore mainly an expression of their size relative to their maturity and the removal of the size limitation by higher levels of nutrition and more rapid growth can largely eliminate their poorer performance.
The effect of source of nitrogen and level of its supplementation on the performance of growing-fattening bulls
Authors: Levy D. , Holzer Z. , Samuel V. , Bruckental I. 
Published: September 2010

ABSTRACTTwo feeding trails were made and in both all the diets given contained about 11 MJ metabolizable energy (ME) per kg dry matter (DM).In trial 1, diets containing three concentrations of crude protein (CP) were given to a total of 84 Friesian bulls in each of three stages of growth. They were, in stage 1 (150 to 250 kg live weight) 130, 145 and 160 g CP per kg dietary DM; in stage 2 (250 to 350 kg live weight) 110, 130 and 145 g CP per kg dietary DM; in stage 3 (350 kg to slaughter) 95, 110 and 130 g CP per kg dietary DM. In stages 2 and 3, the source of supplementary nitrogen at each CP concentration was either soya-bean meal or non-protein nitrogen (NPN) giving six combinations of concentration and source of dietary CP. Live-weight gains in stage 1 were 1·52, 1·60 and 1·58 kg/day respectively (P > 0·05). In the stages involving both concentrations and source of nitrogen (soya-bean meal in parentheses), the mean daily live-weight gains were (1·40), 1·38, (1·32), 1·34 (1·34) and 1·31 kg for stage 2 (F > 0·05) and (1·14), 1·14, (1.24), 1·16, (1·06) and 1·08 kg for stage 3 (P < 0·05), for the diets of 130, 145 and 160 g CP per kg diet respectively.Trial 2 consisted of six stages of growth, the first five of 45 days duration and the sixth of varying length up to a predicted slaughter weight, and seven dietary treatments. Treatment 1 was a negative control (NC) with a dietary CP concentration of 90 g/kg DM. For the other six treatments two concentrations of dietary CP were given; 120 g/kg and 140 g/kg in stages 1 and 2 and 100 g/kg or 120 g/kg in stages 3 to 6. Dietary CP concentration was increased by the addition of NPN, fish meal or soya-bean meal. A total of 98 Friesian bulls were used with an initial average live weight of 185 kg. Daily gain of the NC group in the six stages of the trial was 0·86, 0·97, 101, 1·13, 1·07 and 1·00 kg for stages 1 to 6 respectively. From the results it was concluded that feeding NPN is not efficient at live weights lower than 250 kg and that there is no advantage to feeding fish meal over soya-bean meal in diets of medium energy concentration at live weights heavier than 250 kg.
Performance of British Landrace pigs selected for high and low incidence of halothane sensitivity
Authors: Simpson S. P. , Webb A. J. , Wilmut I. 
Published: September 2010

ABSTRACTHalothane positive and negative selection lines were established to estimate the effects of the halothane gene on performance in British Landrace pigs. Incidences of positive reaction diverged from 0·12 in the foundation generation to 0·93 in the positive and to 0·02 in the negative line in generation 4. Differences in litter productivity as a trait of the dam were estimated from a total of 399 positive × positive and negative × negative parity 1 and 2 matings in generations 1 to 4.Compared with negative contemporaries, positive females showed non-significant reductions in litter size at birth (−0·10, s.e. 0·26) and at 42 days (−0·28, s.e. 0·26), accompanied by significant reductions in average piglet weights at birth (−0·11, s.e. 0·02 kg) and 42 days (−0·4, s.e. 0·2 kg). There were no differences in conception rate or adult live weights. A subsample of 69 parity 2 and 3 sows slaughtered 30 days after mating showed no significant difference in ovulation rate or embryo survival, but for positive dams the length of embryos was significantly reduced (−3·1, s.e. 1·1 mm).The study suggests that the principal effect of the halothane gene was in reducing foetal growth rather than litter size. However, the phenotypic difference is expected to under-estimate the genetic difference between homozygotes, and it was not possible to distinguish the effects of dam and offspring genotypes. The present economic loss of roughly £4·70 per positive litter would be unlikely to justify elimination of the gene from a purebred maternal Landrace herd.
The effect of air filtration on air hygiene and pig performance in early-weaner accommodation
Authors: Carpenter G. A. , Cooper A. W. , Wheeler G. E. 
Published: September 2010

ABSTRACTThe effects of an internal recirculating air filter on air hygiene and pig performance were studied using two groups each of 100 early-weaned pigs from a commercial herd. The two groups were housed in separate rooms under identical conditions except that one room contained a recirculating air filter. Five trials were carried out, but the same records were not kept in all trials. The air throughput of the filter was similar to the installed ventilation capacity (0·9 m3/s). The filter material nominally removed particles > 5 μm. Distribution ducts discharged the filtered air downwards over the pigs' lying area at a velocity of 0·3 m/s. At locations close to the pigs, the most representative proportional reductions of total particles, dust mass, and bacterial colony-forming particles were 0·58 (P< 0·01), 0·73 (P< 0·01), and 0·51 (P< 0·01), respectively. No differences in growth rate or health of pigs after 3 to 4 weeks were observed between the rooms but the pigs originating from the room containing the air filter reached a marketable state 6 to 8 days earlier than the control group pigs on the three occasions that this aspect was monitored (P< 0·0·01).
On the derivation of economic weights in livestock improvement
Authors: Smith C. , James J. W. , Brascamp E. W. 
Published: September 2010

ABSTRACTThe use of profit equations for deriving economic weights (the value per unit improvement in a trait) in the genetic improvement of livestock has led to anomalies both in theory and in practice. These anomalies can be removed by imposing two conditions. One is that any extra profit from genetic change that can be matched by rescaling the size of the production enterprise should not be counted since it can be achieved without any genetic change. Only savings in cost per unit of product value should be included. The second condition is that changes that correct previous inefficiency in the production enterprise should not be counted. Thus, it is assumed that resources are efficiently used, and changes in output will require proportional changes in input. This means that fixed costs, like variable costs, should be expressed per unit of output, rather than as a fixed total enterprise cost. Improvement effort spent on traits that redress current inefficiencies in a production enterprise is of local and temporary value and is at the opportunity cost of improvement of other traits that save costs per unit of product value and are of permanent and general value. Application of these two conditions is shown to give economic weights that are identical on different bases; scaled output value, input or profit; fixed output value, input or profit; and zero profit. They were also equivalent to economic weights derived as the cost per unit product value from an economic efficiency index. The dilemma of different economic weights for different perspectives in production (unit of product, animal, producer, investor, and consumer) is also resolved.
Performance of young steers offered silage or thermo-ammoniated hay with or without a fish-meal supplement
Authors: Gibb M. J. , Baker R. D. 
Published: September 2010

ABSTRACTAn experiment was carried out to examine the performance of young steers given basal diets of either silage or ammoniated hay ad libitum, with or without a daily supplement of fish meal, equivalent to 0·75 g/kg live weight, over 16 weeks. Serial slaughter of animals was carried out to examine changes in body composition during the winter feeding period and the subsequent grazing season.There was no difference in the intakes of hay and silage organic matter over the 16 weeks of treatment. Despite the increased intake of nitrogen on the ammoniated-hay diet there was no increase in the rate of protein gain. By turn-out the steers given silage had higher empty body and carcass weights, and greater contents of fat and energy. The increased rates of empty body-weight, carcass, protein, water and energy gains achieved when the supplement was given were similar for both basal diets. There was no effect of winter feeding treatment on changes in body composition during the grazing period, so that at the end of the summer period the silage-fed animals still had heavier empty body and carcass weights. Attention is also drawn to the possible dangers of feeding hay treated with anhydrous ammonia at high temperatures to such cattle.
Effects of body condition, food intake and temporary calf separation on the duration of the post-partum anoestrous period and associated LH, FSH and prolactin concentrations in beef cows
Authors: Wright I. A. , Rhind S. M. , Russel A. J. F. , Whyte T. K. , McBean Alison J. , McMillen S. R. 
Published: September 2010

ABSTRACTAn experiment was conducted to examine factors affecting the length of the post-partum anoestrous period and associated effects on LH, FSH and prolactin. Forty-six cows (24 Hereford × Friesian and 22 Blue-Grey) ranging in body condition score at calving from 1·50 to 2·75 were used. They were individually fed chopped barley straw and concentrate at either 50 (low) or 91 (high) MJ metabolizable energy per day from calving. At 34 days post partum half the cows were separated from their calves for 48 h. The duration of the post-partum anoestrous period was estimated from progesterone concentrations in thrice weekly blood samples. Blood samples were collected every 20 min for 10 h periods immediately prior to calf separation, during the last 10 h of calf separation and 1 week later. All samples were analysed for LH, and every third sample was analysed for FSH and prolactin.There were no significant effects of genotype, feeding level or calf separation on the length of the post-partum anoestrous period. There was a negative association between body condition score at calving and the length of the anoestrous period, with each unit increase in body condition score reducing the anoestrous period by 43 (s.e. 20) days. There was some evidence that feeding level affected the number of thin cows (body condition score ≤2·25 at calving) which were still acyclic at the end of the experiment, but not the number of fat cows (body condition score ≥2·5 at calving).FSH levels were not affected by any of the factors examined. Prolactin concentrations were higher in fatter cows, in cows on the higher level of feeding and in Blue-Grey cows. Prolactin concentrations decreased during the period of calf separation. Genotype and feeding level had no effect on LH concentration or LH pulse frequency. LH pulse frequency was increased (P < 0·05) during the period of calf separation, but there was no effect 1 week later. There was a significant positive relationship between LH puise frequency and body condition score at calving in two of the three sampling periods.It is suggested that the effect of body condition on the duration of the post-partum anoestrous period i s mediated through effects on LH pulse frequency.
The effects of genotype and post-weaning nutrition on compensatory growth in cattle reared as singles or twins
Authors: Wright I. A. , Russel A. J. F. , Hunter E. A. 
Published: September 2010

ABSTRACTThirty-five Charolais × Blue-Grey and Charolais × (Hereford × Friesian) weaned suckled calves which had been reared as either singles or twins and 19 single-reared Luing and Charolais × Luing weaned suckled calves were given silagead libitumsupplemented with either 0·75 or 2·5 kg rolled barley per day during the post-weaning winter. During summer the cattle continuously grazed perennial ryegrass swards. The high level of barley supplementation increased winter live-weight gain by 0·25 kg/day (P< 0·001). During summer the cattle from the low level of feeding gained weight at 0·09 kg/day (P< 0·05) faster than those from the high level of feeding. However, by the end of the summer grazing period the cattle on the low level of feeding were proportionately only 0·97 the weight of the animals on the high level of feeding.During winter the performance of all genotypes was similar, but at pasture the Luing cattle gained less weight (P< 0·01) than the single-reared Charolais-cross genotypes.Twin-reared cattle took 55 days longer to reach slaughter condition, but produced carcasses of equal weight and fatness to those from single-reared cattle.The twin-reared cattle on the high level of feeding and the single-reared cattle on the low level of feeding attained a similar weight, body condition and ultrasonic backfat at turn-out. Thereafter, their herbage intakes and live-weight gains were identical suggesting that previous level of feeding per se is unimportant in determining an animal's subsequent intake and performance. Rather it is the body composition at a given age, irrespective of the pathway followed to attain that composition, that determines performance thereafter. It is also suggested that the inability of cattle to compensate for a reduction in level of nutrition during the first 3 to 4 months of life is due to the lack of potential for fat deposition, and there is thus limited opportunity for nutritional manipulation of body composition at that age.