bluuebunny/crossref_metadata_2025_split huggingface dataset:
Body composition of British and Zebu × British cattle in northern Australia 2. Yield of carcass and its relationship to other expressions of composition
Authors: Seebeck R. M. 
Published: September 2010

ABSTRACTThe variation in yield of carcass of Shorthorn-Hereford (SH), Africander x SH (Ax), Brahman x SH (Bx) and late-castrated Brahman x SH (Bx(late)) steers of the F, generation was examined in relationship to rate of growth and other expressions of composition.On a fasted body-weight basis, yield of carcass was shown to be related to rate of growth. Of the non-dressed-carcass parts of the body, yield of carcass was particularly related to the proportion of gut contents. When this was taken into account, the relationship between yield of carcass and rate of growth was diminished but not eliminated, and breed differences in yield of carcass still remained.Relationships between yield of carcass (relative to the empty body), carcass composition and offal composition are complex, due to the fact that each of these three shape vectors are related to size and rate of growth. Nevertheless, these shape vectors were shown to be related to each other independently of size. However, there was some confounding between the effect of rate of growth on a given shape vector and the effect of the other shape vector, particularly with respect to the relationship between yield of carcass and carcass composition. Nevertheless, it could be said that the proportion of the variation in a particular shape vector that was associated with variation in rate of growth, is explained more simply in terms of variation in another shape.Within breed, animals with a high yield of carcass had a high ratio of muscle to bone plus fascia and tendons in the dressed carcass.The large difference in yield of carcass between breeds.could be accounted for by differences in offal composition, but not by differences in carcass composition. Breed differences in carcass composition at the same size were accounted for by either yield of carcass or offal composition. However, breed differences in the relationship of carcass composition to size were not accounted for by these shape vectors. The effect of yield of carcass on carcass composition was itself accounted for by offal composition.
Effect of passive immunization against testosterone on the reproductive performance of Scottish Blackface ewes in different levels of body condition at mating
Authors: Rhind S. M. , Gunn R. G. , Morris B. A. , Clayton J. , Leslie I. D. , Gittus G. 
Published: September 2010

ABSTRACTThe effect of passive immunization against testosterone on reproductive performance was investigated in 180 mature Scottish Blackface ewes in different levels of body condition at mating. Ewes were fed to achieve a wide range of condition (scores 1·5 to 3·0) by 2 weeks before a synchronized mating. During the week before mating, 90 ewes were each injected with 32 ml of a neat anti-testosterone antiserum (1: 96 000 initial titre) and 90 ewes were untreated. At about 55 days after mating, 50 immunized and 50 control ewes were slaughtered and the numbers of corpora lutea and embryos present were recorded. The proportion of immunized ewes that conceived during two periods of mating was in excess of 0·9 in all condition categories. By contrast, untreated ewes in the low condition category (score =£ 2·00) had significantly lower conception rates than ewes in higher condition categories. Immunized ewes with condition scores of 2·50 or less at mating had significantly higher ovulation rates, litter sizes and lambing rates compared with control ewes, while immunized ewes with scores of 2·75 or higher were not significantly different from control ewes in these measurements. There was no effect of immunization on embryo mortality rate, lamb sex ratio, lamb birth weight, or lamb survival rate in the 1st week after birth.
A note on the effect of exposing gilts to a mature boar at 140 days of age
Authors: Walton J. S. 
Published: September 2010

ABSTRACTFifty-six Landrace ♂ x Yorkshire ♀ gilts were divided at 140 days of age into four groups in a 2 x 2 factorial design whereby they were exposed continually (BE) or not exposed (NE) to a mature boar and were or were not blood sampled twice weekly for progesterone determinations.There was no effect of BE on the age at the first or second ovulation. Since detection of oestrus was only 70·80% accurate, BE apparently delayed the onset of first and second oestrus by 16 days (p = 0·06). Blood sampling advanced first oestrus by 15 days (F = 0·07) and second oestrus by 32 days (P = 0·001).The results suggest that gilts are unlikely to be responsive to boar exposure at 140 days of age, that observations of oestrus alone may be a misleading end-point of the effect of boar exposure and that the use of blood sampling for the measurement of progesterone as an index of ovarian activity may attenuate the response to stimuli intended to advance puberty in the gilt.
The response of store lambs to protein supplementation of a roughage-based diet
Authors: Hassan S. A. , Bryant M. J. 
Published: September 2010

ABSTRACTThe response of 35-kg store lambs to diets containing increasing rumen-undegradable nitrogen (UDN) concentrations was measured by live-weight gain and nitrogen (N) balance. A range of UDN concentrations from 2·4 to 7·2 g/kg dietary dry matter was achieved by supplementing a basal diet of NaOH-treated barley straw, tapioca, extracted rapeseed meal and minerals with both formaldehyde-treated rapeseed meal and fish meal. Sufficient diet to provide maintenance and a growth rate of 150 g/day was given to the lambs, according to live weight. Increasing levels of UDN promoted a linear increase in live-weight gain and N retention. However, the response to fish meal was greater than that for formaldehyde-treated rapeseed meal. The true digestibility of N of formaldehyde-treated rapeseed meal determined in chickens by ileal analysis was low in comparison to that of untreated rapeseed meal.
Use of embryo transfer in genetic improvement of sheep
Authors: Smith C. 
Published: September 2010

ABSTRACTEmbryo transfer following multiple ovulation could allow faster rates of genetic change in sheep, by increasing the effective female reproductive rate. The gains would come from lower generation intervals or increased selection among females, or both. They require good embryo transfer rates at 6 to 8 months of age. These are not adequate at present and need to be improved by research and development, justified by the extra genetic gains shown here to be possible. If high rates of embryo transfer (10 progeny per donor) could be achieved, then, with appropriate selection schemes, the rates of genetic change could be doubled compared with efficient schemes using normal reproduction. This applies to most traits, to those measured before reproductive age (growth traits and carcass traits estimated in the live animal), to female reproductive traits and to wool traits measured at 14 to 16 months of age. With moderate rates of embryo transfer (5 progeny per donor), gains of 50 to 70% in genetic response could be obtained. To limit the rate of inbreeding to moderate levels in a closed selection flock, some 100 to 200 females (1000 progeny) would be required. Application of the methods may be difficult with current breeding structures, and the development of special nucleus selection stocks i s proposed.
The voluntary intake and digestibility of straw diets and the performance of wether sheep as influenced by formaldehyde treatment of soya-bean meal
Authors: Alawa J. P. , Hemingway R. G. 
Published: September 2010

ABSTRACTIn two experiments, straw diets were supplemented with a concentrate mixture containing either untreated or formaldehyde-treated soya-bean meal. In experiment 1, adult wether sheep were given straw/concentrate mixtures in a 3:1 ratio (air-dry basis) in restricted amounts. In experiment 2, these proportions were adjusted to 3:2 and the growing lambs were offered straw at proportionately 0·05 to 0·1 greater than that eaten daily.In experiment 1, formaldehyde treatment of soya-bean meal depressed apparent nitrogen (N) digestibility (P < 0·001) although diet organic-matter digestibility was not affected. Formaldehyde treatment also tended to reduce N retention in experiment 1, whereas with growing lambs in experiment 2, it led to improved N retention. Plasma urea concentrations were reduced as a result of formaldehyde treatment of soya-bean meal. Digested N was more efficiently utilized by sheep given the treated soya-bean meal diet in experiment 2 but not in experiment 1. Lambs given the treated soya-bean meal diet tended to gain more live weight with marginally superior food conversion ratios while consuming similar amounts of dry matter as those given the untreated soya-bean meal-supplemented diet.
Reproductive performance and survival of young one-humped camels on Kenya commercial ranches
Authors: Wilson R. T. 
Published: September 2010

ABSTRACTData are provided from four Kenya ranches relating to seasonality of breeding, age at first parturition, parturition interval, sex ratio, gestation period and the early survival of young in one-humped camels. A total of 799 births was recorded. Births occurred throughout the year with no marked peak, there being no significant correlation of conception with rainfall. Age at first parturition (no. = 37) was 54·3 months. Parturition interval (no. = 460) was 20·2 months and was significantly affected by the random effects of the dam as well as by the fixed effects of the herd and the survival of the previous young. The sex ratio at birth was 1·06 males to 1·00 female. Gestation period was 377·1 days, and was not significantly affected by any of herd, month of conception, sex of young or age of animal. Abortions amounted to 11·6% of all births with the total of pre-weaning losses (including abortions) being 25·7%. Improving familiarity of the owners with the animals and better management could lead to considerable increases in performance.
The effect of dietary energy level and protein: energy ratio on nitrogen and energy balance, performance and carcass composition of pigs weaned at 3 weeks of age
Authors: Zhang Y. , Partridge I. G. , Mitchell K. G. 
Published: September 2010

ABSTRACTFour diets were formulated from cereals, animal and vegetable protein supplements and tallow, to contain digestible energy (DE) concentrations of 14·1 or 17·1 MJ/kg and crude protein concentrations of 12·7 or 17·0 g/MJ DE in a 2 X 2 factorial design. In each of two experiments, pigs were weaned and allocated to dietary treatments when 21 days old and were fed twice daily to appetite. In experiment 1, six replicates of four male littermates were used. They were individually fed in metabolism cages and continuous energy and nitrogen (N) balances were made from 28 to 63 days of age. In experiment 2, three male and three female pigs were slaughtered at weaning to determine initial body composition, and three replicates of four littermates of each sex were allocated to the dietary treatments. The latter were fed in treatment groups in flat-deck pens and slaughtered at 63 days of age.In experiment 1, increased energy concentration reduced food intake only slightly and improved liveweight gain and food: gain ratio; higher protein concentration increased gains only at lower energy concentration. Daily N balance improved with increased energy and protein concentration but the response to protein was greater with the low energy diet. Dietary energy was efficiently utilized even with 163 g tallow per kg diet. From 63 days of age until slaughter at 60 kg all pigs were given the same grower diet to appetite. Performance was not affected by previous treatments.In experiment 2, food intakes were higher than in experiment 1 and tended to be reduced to a greater extent with the higher energy concentration; live-weight gains were similar for all treatments and food: gain ratio tended to improve in response to higher energy and protein concentrations. Dietary energy level had no effect on carcass fat content but the higher protein level reduced fat deposition. N retention tended to be lower for the low energy, low protein diet compared with the other three diets. Dietary effects on the amino-acid composition of the carcass were small. Carcass amino-acid ratios at 3 and 9 weeks were similar to published values and there was a tendency for higher amino-acid concentrations (g/16 g N) at 9 weeks than at 3 weeks.
A note on the effect of zeranol administration on oestrous cycle length and hormonal profiles in cows
Authors: Beal W. E. , Good G. A. , Putney D. J. , Johnson G. L. 
Published: September 2010

ABSTRACTZeranol is an anabolic agent with oestrogenic actions commonly used in fattening beef cattle. This experiment was designed to determine the effects of zeranol administration on oestrous cycle lengths, plasma progesterone concentrations and the exhibition of oestrus in mature cows. Administration of 36-mg zeranol implants during the early, middle or later portion of the oestrous cycle did not alter the length or persistence of oestrous cycles, nor were progesterone profiles different from those observed in untreated cows. Some cows that received zeranol exhibited a prolonged oestrus. The regularity of oestrous cycles in cows treated with zeranol indicates that it may be possible to utilize zeranol as an anabolic and lactopoetic agent in post-partum beef cows.
A note on the response of pigs weaned at 28 days to dietary protein
Authors: Campbell R. G. , Taverner M. R. 
Published: September 2010

ABSTRACTThirty-six piglets were used to investigate the effect of six concentrations of dietary protein ranging from 155 to 235 g/kg, and corresponding dietary lysine concentrations from 10·1 to 15·4 g/kg, on the performance of pigs weaned at 28 days of age and growing between 7·5 and 20 kg live weight. Voluntary food intake was not significantly affected by dietary protein, and growth rate increased with increase in dietary protein and lysine up to 167 and 10·9 g/kg respectively (0·75 g lysine per MJ digestible energy (DE)). Food: gain ratio improved significantly with each increase in dietary protein and lysine up to 177 and 11·6 g/kg (0·79 g lysine per MJ DE) respectively.
Factors affecting pre- and post-weaning growth and body composition in kid goats of the Granadina breed
Authors: Sampelayo M. R. Sanz , Muñoz F. J. , Lara L. , Extremera F. Gil , Boza J. 
Published: September 2010

ABSTRACTThirty-two kid goats of the Granadina breed were used in four trials of three factors: milk type (goat milk and milk replacer), intake level (1·86 and 2·48 maintenance) and slaughter age (15, 30, 45 and 60 days). Weaning was carried out between the 31st and 45th days. The composition of the carcass and its different cuts and the development of the stomach compartments were studied.Both the high intake level and use of goat milk produced a statistically greater fat proportion in the carcass. At 30 days of age in kids given goat milk at the high intake level the fat proportion of the carcass was 130 g/kg. The variations in bone proportions were inverse to those for fat. The muscle proportions were affected by age, overall. The tissue composition of the different cuts showed similar responses to those in the carcass. The stomach compartments were affected most by age.The results show that kids of the Granadina breed have a good fattening capacity. The feeding and weaning system used here produced kids by 60 days of age with stomach compartments similar in proportion to those of adult goats.
Breed and sex differences in equally mature sheep and goats 2. Body components at slaughter
Authors: Thonney M. L. , Taylor St C. S. , Murray J. I. , McClelland T. H. 
Published: September 2010

ABSTRACTAnimals from Soay, Welsh Mountain, Southdown, Finnish Landrace, Jacob, Wiltshire Horn and Oxford Down sheep breeds and a breed of feral goats were slaughtered when 0·40, 0·52, 0·64 or 0·76 of mature body weight. The effects of stage of maturity, breed and sex were examined in the following traits: gut content as a proportion of slaughter weight; blood, omental plus mesenteric fat, perirenal fat, alimentary tract, ‘remainder’ of non-carcass parts and hot carcass, each as a proportion of fleece-free empty body weight; also shoulder, rib, loin and gigot joints and their commercially higher-valued (prime) and lower-valued cuts, each as a proportion of carcass weight.As a proportion, gut content declined as animals matured, as also did blood, alimentary tract, ‘remainder’, prime shoulder, shank and prime gigot. Increasing proportions were internal fat depots, the hot carcass, rib, loin and gigot flank. Males accumulated significantly less internal fat and more shoulder than females.When equally mature in live weight, males had proportions that were significantly lower for perirenal fat, rib and gigot and higher for shoulder and pelt plus head, feet and organs.There were significant inter-breed regressions on mature body weight. The proportion of blood, alimentary tract, pelt plus head, feet and organs, and prime gigot declined with breed size, while hot carcass, brisket, rib and loin proportions increased. These regressions were attributed to a non-random sample of breeds. The small Soay breed had proportions of internal fat and hot carcass which were well below average, and higher proportions of blood, alimentary tract and ‘remainder’. Soay sheep also had a higher proportion of commercially higher-valued cuts in the carcass. In contrast, the large Oxford Down breed had low proportions of non-carcass components (except alimentary tract) and high proportions of lower-priced cuts and prime rib. Feral goats had a greater, and Southdown sheep a smaller, proportion of gut content than other breeds.
The effect of age and growth traits on puberty and reproductive performance in the gilt
Authors: Burnett P. J. , Walker N. , Kilpatrick D. J. 
Published: September 2010

ABSTRACTAn experiment involving 320 gilts was conducted to investigate the effects of age and growth traits on puberty attainment and reproductive performance in gilts given boar stimulation with or without exogenous gonadotropins. Following ad libitum feeding during rearing, groups of gilts were stimulated for puberty at one of four ages, namely 130, 150, 170 or 190 days. Within each age group, gilts were selected to maximize the variation in live weight, relocated, mixed and allocated to two treatments in a randomized-block design: (a) mature boar contact (boars only) and (b) boar contact plus an intramuscular injection of 400 i.u. pregnant mare's serum gonadotropin + 200 i.u. human chorionic gonadotropin (boars + PG600). Gilts were mated at puberty and slaughtered at 35 days post coitum.For the gilts on the boars-only treatment, the interval from stimulation to puberty decreased significantly (P < 0·05) and became less variable with ascending age at stimulation. Increasing live weight at a given age also reduced the interval from stimulation to puberty. Multiple regression equations involving age, live weight and backfat thickness at stimulation and growth rate from birth to stimulation were calculated to obtain a prediction equation for the interval from stimulation to puberty. The effects of age and live weight at mating on ovulation rate, embryo survival and number of live embryos 35 days post coitum were not significant.For the gilts on the boars + PG600 treatment, 92% attained puberty within 6 days of treatment, with a non-significant trend to improve with increasing age. Mating rates were similar to those on the boars-only treatment (90%). Ovulation rates were higher (P < 0·001) but embryo survival rates were lower (P < 0·001) in the boars + PG600 group, resulting in similar litter size at 35 days post coitum in the boars-only and boars + PG600 treatments. There was a non-significant trend for litter size to increase with age in the boars + PG600 treatment. Thirty-eight of the gilts treated with hormones failed to conceive and 53% were found by ovarian morphology at slaughter to be cycling normally with a tendency for this proportion to increase with age.
Insulin-like growth factor 1, growth and body composition in red deer stags
Authors: Suttie J. M. , Corson I. D. , Gluckman P. D. , Fennessy P. F. 
Published: September 2010

AbstractInsulin-like growth factor 1 (IGF1) correlates with antler growth and body growth in penned red deer stags. The present study aimed to investigate the relationships among plasma concentration of IGF1, body growth and carcass composition in grazing stags. Twenty-eight 10-month-old stags were kept at pasture from September to February. They were bled, weighed and their antlers measured fortnightly. Plasma was analysed for total IGF1. All stags were slaughtered in February (aged 15 months); organ weights were recorded and the carcasses were analysed chemically for water, fat and ash. The stags began the study weighing 60·7 (s.e. 1·4) kg and were 96·3 (s.e. 2·0) kg at the end. They grew rapidly in spring and early summer but growth rate slowed in mid summer before increasing again in late summer.Total plasma 1GF1 for each stag throughout the study correlated positively with antler length (P < 0·001), total live-weight gain (P < 0·001), hot carcass weight (P < 0·01), fat-free carcass weight (P < 0·01), carcass fat weight (P > 0·05) and carcass fat percentage (P > 0·05). Thus IGF1 correlated significantly with all measures of body weight except fat. IGF1 correlated positively with antler growth rate (P < 0·001) calculated individually for each stag during each fortnight. IGF1 correlated positively with the spring phase of live-weight gain calculated as above (P < 0·001) but negatively (P < 0·01) with live-weight gain during the late summer growth phase. The relationships between IGF1 and growth in penned stags also pertain in grazing animals, and in addition 1GF1 is closely associated with carcass lean mainly via an overall effect on body size.
A note on attainment of puberty of september-born early-maturing ewe lambs in relation to level of nutrition
Authors: Forcada F. , Abecia J. A. , Zarazaga L. 
Published: September 2010

The attainment of puberty in September-born early-maturing ewe lambs was studied at Zaragoza (latitude 41° 40' N). Thirty twin Salz females were allocated to two groups receiving two nutrition levels after 3 months of age: high (500 g/day lucerne hay and 500 g/day concentrate) (H) and low (500 g/ day lucerne hay) (L). Oestrus was detected daily by aproned rams. Corpora lutea were counted after oestrus and plasma progesterone levels monitored each week.In the first breeding season (January to February) the percentage of females showing sexual activity (silent emulation or oestrus and ovulation) was higher in the H compared with the L group (67 and 20%; P < 0/05). Nonpubertal oestrus before the main breeding season was detected in 67% of animals. In the main breeding season and for H and L groups respectively, percentage of females showing silent ovulation before puberty was 67 and 33% and mean age at puberty extended to 319 (s.e. 4-8) and 314 (s.e. 3·7) days. Ovulation rate at puberty was 1·73 (s.e. 0·13) and 1·33 (s.e. 0·15) respectively (P < 0·05).