bluuebunny/crossref_metadata_2025_split huggingface dataset:
A note on the reproductive performance of greyface ewes in moderately fat and very fat condition at mating
Authors: Rhind S. M. , Gunn R. G. , Doney J. M. , Leslie I. D. 
Published: September 2010

ABSTRACTOestrous activity, ovulation rates and embryo survival rates were investigated in Border Leicester × Scottish Blackface (Greyface) ewes with condition scores of approximately 2·75 (moderately fat) or 3·5 (very fat) at mating. Four of a group of 20 very fat ewes failed to show oestrus at the expected time. Very fat ewes had a higher mean ovulation rate (3·36 v. 2·33; P < 0·05) but a slightly lower potential lambing rate (1·10 v. 1·42 lambs born per ewe put to ram) than the moderately fatewes.
The effects of fat thickness and sex on pig meat quality with special reference to the problems associated with overleanness 2. Laboratory and trained taste panel results
Authors: Wood J. D. , Jones R. C. D. , Francombe M. A. , Whelehan O. P. 
Published: September 2010

ABSTRACTEvaluations of meat quality were made of 300 carcasses, of average weight 58 kg, falling into three fatness groups, 8, 12 and 16 mm for P2 fat thickness. There were equal numbers of entire males and gilts. An increase in fat thickness was associated with an increase in the firmness of loin and shoulder backfat, a reduced incidence of fat separation and changes in the composition of both muscle and backfat: the concentration of lipid increased and that of water decreased, more markedly in backfat. In addition, the concentration of collagen in backfat decreased. The loin joint was visually most attractive when P2 was 11 mm, attractiveness decreasing below and particularly above this value. Eating quality of grilled chops was assessed in a representative subsample of 96 pigs falling into the 8-mm and 16-mm P2 categories. The only statistically significant difference observed between these extremes of fat thickness was in juiciness which was lower in the leaner pigs; the correlation between juiciness score and m. longissimus lipid concentration (‘marbling fat’) was 0·31. Juiciness did not influence the assessment of overall eating quality which showed no association with fatness. Entire males of similar backfat thickness to gilts (12 mm P2) had a higher concentration of water and lower concentration of lipid in backfat and slightly softer backfat. There were no differences in eating quality, or in the presence of abnormal odours or flavours, between entire males and gilts. These results confirm those obtained in butcher and consumer panel tests in the same carcasses.
Lifetime growth and carcass composition of heifers and steers non-implanted or sequentially implanted with anabolic agents
Authors: Keane M. G. , Drennan M. J. 
Published: September 2010

ABSTRACTSixty-four (48 female and 16 male) spring-born Hereford × Friesian calves were used to examine the effects of sex type, heifer slaughter age and implantation with anabolic agents on growth and carcass composition. Non-implanted and implanted heifers were slaughtered after 491, 612 and 731 days and non-implanted and implanted steers (castrated on day 81) were slaughtered after 731 days. Implantation was with 36 mg resorcylic acid lactone (RAL) on days 81 and 171 and RAL plus 300 mg trenbolone acetate on days 395, 491, 583 and 658.Carcass weights of non-implanted and implanted heifers slaughtered at 491, 612 and 731 days were 189 and 206, 218 and 235 and 290 and 326 (s.e.d. 10·1) kg respectively. Carcass lean, bone and fat weights and fat proportion increased with increasing slaughter age but proportions of lean and bone decreased.There was no difference between heifers and steers in growth rate to 395 days but from 395 to 731 days the steers grew faster than the heifers. Non-implanted and implanted steer carcass weights at 731 days were 297 and 355 (s.e.d. 9·5) kg respectively. Steer carcasses had higher lean and bone proportions and a lower fat proportion than heifer carcasses. Implanted animals had heavier carcasses than non-implanted animals and all of the extra carcass weight consisted of lean and bone. The results indicate that non-implanted and implanted heifers and steers had similar lean proportions when the heifers were 31 and 70 kg carcass weight respectively lighter than the steers.
The influences of nutrition and management on the growth of red deer calves from weaning to 16 months of age
Authors: Milne J. A. , Sibbald Angela M. , McCormack Heather A. , Loudon A. S. I. 
Published: September 2010

ABSTRACTThe effects of date of weaning, weaning live weight, autumn grazing management and level and pattern of winter nutrition in relation to summer grazing on the live-weight gain of farmed red deer calves to 16 months of age were tested in three experiments.In experiment 1, the effect of two weaning live weights (37 and 46 kg) in September and two levels of autumn and winter nutrition were examined with 48 calves. In October, live-weight gains were positively related to sward height and herbage mass. The calves lost live weight in November. Compensatory live-weight gains of 28 g/day occurred at summer pasture after the low level of winter nutrition. Weaning live weight had a major influence on live weight at 16 months of age.In experiment 2, the effects of maintenance, ad libitum and intermediate treatments were compared using 50 calves given a complete diet in winter. The intermediate treatment consisted of a maintenance followed by an ad libitum level of feeding. Compensatory live-weight gains of 49 g/day occurred at pasture with the intermediate treatment achieving complete live-weight compensation at 16 months of age.In experiment 3, the effect of two weaning dates (19 September and 14 November) on live-weight gain of calves and on the date of subsequent calving of hinds were compared with 34 lactating hinds. There was no difference in live-weight gain of calves between weaning dates but the subsequent calving date was delayed by 8 days from those hinds weaning in November.A management system is advocated with weaning in September, housing in November after grazing sown swards greater than 6 cm, a pattern of a low followed by a high level of nutrition in winter and the summer grazing of sown swards maintained at 4 to 6 cm.
Prediction of intake by cattle from degradation characteristics of roughages
Authors: Ørskov E. R. , Reid G. W. , Kay M. 
Published: September 2010

ABSTRACTFive different straws consisting of two varieties of winter barley, two varieties of spring barley and one variety of winter wheat were chosen due to differences in degradation characteristics determined by using nylon bags incubated in the rumen of cattle and describing the straw using the equation: p = a + b (1 – e–ct). To increase variation in degradability, batches of the same straws were also treated with anhydrous ammonia in a sealed oven.The straws were subsequently offered ad libitum to groups of steers given a daily supplement of 1·5 kg concentrate and untreated straws were supplemented with urea. The dry-matter intake (DMI) of the straws varied from 3·4 to 5·7 kg/day, the digestible DMI from 1·4 to 3·5 kg/day and growth rate from 106 to 608 g/day.By using multiple regression of a, b, c from the exponential equations characterizing degradability of the straw, the correlation coefficients with DMI, digestible DMI and growth rate were 0·88, 0·96 and 0·95 respectively.
Effects of selection for divergent ultrasonic fat depth in rams on progeny fatness
Authors: Bennett G. L. , Meyer H. H. , Kirton A. H. 
Published: September 2010

ABSTRACTFat depths of Southdown and Suffolk rams were ultrasonically measured several times prior to 18 months of age. Ultrasonic measurements were regressed on live weight and deviations from this regression were standardized and summed to select rams with high and low fat depth to produce crossbred progeny for slaughter. An average of 3·24 standard deviations separated high and low sires. Progeny were slaughtered at two ages to determine differences in carcass fatness and its development. A significant difference of 0·5 mm fat depth over the loin eye muscle was found between progeny of low and high sires. Progeny from Suffolk high sires had greater tissue depth over the rib and higher kidney fat weight than those from Suffolk low sires but differences were small or reversed in Southdown progeny. Low progeny had significantly less estimated carcass chemical fat than high progeny. Fat depth C increased less in low progeny between early and late slaughter ages. However, no difference in partition of carcass weight gain to fat weight gain was observed between high and low progeny. Differences in fat weight between high and low progeny, as well as between Southdown and Suffolk progeny, appeared to have occurred prior to the earlier slaughter age.
Influence of diurnally fluctuating high temperature on growth and energy retention of growing pigs
Authors: Giles L. R. , Dettmann E. Belinda , Lowe R. F. 
Published: September 2010

Abstract The effects of two temperatures (thermoneutral, 22°C v. fluctuating high temperature, 35·22°C), four food levels (ad libitum and three levels of food restriction) on growth and energy retention of growing pigs (male and female) was investigated in a 2 × 2 × 4 factorial experiment involving 48 individually penned pigs from 20 to 50 kg live weight. A second experiment was conducted over the 50 to 80 kg liveweight range using a 2 × 2 × 3 design.Mean daily digestible energy (DE) intake, daily gain, P2 backfat thickness, carcass fat proportion, total body energy retained and body energy retained as protein did not differ significantly between the temperature treatments in either experiment. Mean carcass protein proportion was greater at 35·22°C than at a constant 22°C.With pigs given food ad libitum during the 50 to 80 kg phase, an increase in temperature from 22°C to 35·22° reduced daily DE intake by 4·1 MJ (38·9 v. 34·8 MJ or 300 g food per day), reduced energy retention by 2·3 MJ/day (15·6 v. 13·3 MJ/day), and increased carcass protein proportion by 11 g/kg (142 v. 153 g/kg).There was a significant interaction between the effects of sex and temperature on P2 backfat thickness over both live-weight ranges. Female pigs housed at 35·22°C had 2·6 mm less P2 backfat at 50 kg (13 v. 15·6 mm) and 2 mm less at 80 kg (20 v. 22 mm) compared with females housed at 22°C. The P2 backfat thickness of male pigs did not vary at 50 kg (13·2 v. 13·5 mm) but when housed at 35·22°C males had 1·4 mm more P2 backfat at 80 kg (18·2 v. 19·6 mm).
Compensatory growth in cattle grazing different vegetation types
Authors: Wright I. A. , Russel A. J. F. , Hunter E. A. 
Published: September 2010

ABSTRACTFifty-four Charolais-cross weaned suckled calves were used in an experiment to investigate the effects of feeding level during the post-weaning winter on their subsequent performance, when grazing different vegetation types in summer. During winter they were given grass silage and barley at one of three levels (low, medium and high). The winter live-weight gains were 0·50, 0·75 and 0·96 (s.e. 0·019) kg/day (P < 0·001) for the low, medium and high treatments respectively. During summer they grazed either a sown ryegrass pasture (S), a hill reseed (R) or part of an unimproved hill (H).Live-weight gain during summer was inversely related to winter feeding level on all grazing treatments, the mean live-weight gains being 1·01, 0·79 and 0·65 (s.e. 0·027) kg/day (P < 0·001) for the low, medium and high winter feeding levels respectively. Summer treatment significantly affected performance, the live-weight gains being 0·88, 0·94 and 0·61 (s.e. 0·027) kg/day for the S, R and H treatments respectively. There was no interaction between winter and summer feeding treatment on live-weight gain. The organic matter intake was highest on the H treatment but the digestibility of herbage consumed was the lowest, resulting in the lowest digestible organic matter intake.Similar and high levels of performance were obtained on sown ryegrass pastures and reseeded hill land, while unimproved hill vegetation supported only moderate levels of live-weight gain. Compensatory growth occurred when a wide range of vegetation types were grazed in summer.
Modifications to MOET nucleus breeding schemes to improve rates of genetic progress and decrease rates of inbreeding in dairy cattle
Authors: Woolliams J. A. 
Published: September 2010

ABSTRACTThe effect of changes in the mating system on the rates of genetic progress and rates of inbreeding are considered for MOET nucleus breeding schemes. Methods are derived to calculate best linear unbiased predictors of breeding value in MOET schemes and the rate of inbreeding under selection. These are applied to different mating systems in which the numbers of sires and dams, and the number of offspring per sire and offspring per dam, remain constant.Results showed that compared with nested mating systems, factorial mating systems in which the maternal half-sibs are produced instead of full-sibs, could increase genetic progress by 1·12-fold with no additional inbreeding. The increased progress arose through an increase in the selection intensity applied. The rates of inbreeding derived were found to be approximately double those estimated by the formula of Wright (1931) in the absence of selection.In practice, even if a complete factorial system were to increase the generation interval and consequently reduce progress below that predicted, changes in the mating system avoiding this problem could be implemented that would be of immediate benefit.
Estimation of milk consumption curve parameters for different genetic groups of bovine calves
Authors: Mezzadra C. , Paciaroni R. , Vulich S. , Villarreal E. , Melucci L. 
Published: September 2010

ABSTRACTMilk consumption was estimated for crossbred suckled calves from birth to weaning during 2 years. Breed groups utilized were Aberdeen Angus (A) and Charolais (C) sires on Fl Angus-Hereford (and their reciprocals) dams in the 1st year and in the 2nd year, sires A and Nelore (Bos indicus) (N) were used on the same type of dam. The weigh-suckle-weigh technique was employed twice a day to estimate milk consumption on a weekly basis. Estimations were adjusted by least-squares for the effects of genetic group, week of estimation, and their interaction, with sex of calf and calf and cow weights in the week of estimation as covariables. Then a non-lineal regression equation of the form: y = b0Wb1e -b2b2W was fitted for each individual, where y = milk consumption and W = week of estimation. Curves for A and C were very close in their shape, but with a greater consumption (P < 0·01) for C. For the 2nd year, there were differences among A and N both in the shape of the curve and in consumption at the peak of lactation (P < 0·01). Differences in time to peak lactation were also found: for A calves, it was week 9, for C calves week 10 and for N calves week 3·8. The N group showed a sharper decline in persistency than the other groups, suggesting different patterns in milk consumption.
Prediction of the voluntary intake of grass silages by beef cattle 3. Precision of alternative prediction models
Authors: Rook A. J. , Dhanoa M. S. , Gill M. 
Published: September 2010

ABSTRACTThe precision of a number of new models for predicting silage intake by beef cattle was investigated with independent data using the mean-square prediction error and compared with two previously published models (Agricultural Research Council, 1980; Lewis, 1981). The new models generally performed well relative to the previous models.The new models included a number constructed using the technique of ridge regression which were shown to be consistently better predictors than the models obtained from the same estimation data by stepwise least-squares regression. Better prediction was also obtained by reducing the number of variables in the least-squares models below that required to maximize R2 in the estimation data. The poor performance of the least-squares models with the best R2 may be attributed to collinearity between the independent variates in the estimation data.Most of the models considered overpredicted relative to observed intakes. This may have been the result of differences in breed type and management of the animals between the test data and the estimation data used to construct the models, that is the use of the models with the test data involved a degree of extrapolation.It is concluded that ridge regression and deletion of variables offer a positive step forward in intake prediction compared with models based on maximizing R2 in the estimation data. However, further work is needed to clarify the effect of factors such as breed and rearing system on intake and to clarify the usefulness of various fibre measures in intake prediction. A number of new models are proposed which utilize a range of input variables thus allowing flexibility in their use in practical situations.
The dietary energy values of soya-bean oil, tallow and their blends for growing/finishing pigs
Authors: Wiseman J. , Cole D. J. A. , Hardy B. 
Published: September 2010

ABSTRACTTwo fats, soya-bean oil and tallow, were blended in the ratios 70: 30, 50: 50 and 30: 70. The ratios of unsaturated to saturated fatty acids (U/S) of the blends were 3·18, 2·08 and 1·49 respectively; values for soya-bean oil and tallow were 6·69 and 0·93. These five fat sources were each included into a basal diet at levels of 40, 80 and 120 g/kg. The digestible (DE) and metabolizable (ME) energy together with the apparent fat digestibility (AFD) of the experimental diets were measured in a metabolism trial based upon four 4 × 4 Latin squares using 16 gilts of 30 kg initial live weight. Linear equations relating dietary DE and ME values to level of inclusion of fat were extrapolated to 1000 g/kg to obtain values for the fats. DE values for soya-bean oil and tallow were 38·06 and 34·16 MJ/kg respectively. Corresponding data for ME were 35·63 and 32·53 respectively. These figures were used to calculate values of the mixtures. Data thus derived did not differ significantly from those determined directly, indicating that there was no synergism between the two fats. DE values of fats determined as the product of AFD of fats and their gross energy followed similar trends. The majority of the increase in values of fats was associated with a change in the U/S ratio from 0·93 to 2·08.
Rumen degradation of straw. 10. Consistency of differences in nutritive value between varieties of cereal straws
Authors: Ørskov E. R. , Shand W. J. , Tedesco D. , Morrice L. A. F. 
Published: September 2010

ABSTRACTThe consistency of differences between varieties in nutritive value of cereal straws was tested over 3 years consecutively for nine varieties of spring barley and 10 varieties of winter wheat straw and over 2 years consecutively for 12 varieties of winter barley and six varieties of oats. For all varieties there were large year-to-year differences in nutritive value measured by ruminal degradation characteristics using the nylon bag technique. For spring barley there were large differences between varieties and the correlations between varieties in different years were mostly in excess of r = 0·90 for 48-h degradability and maximum potential degradability. For winter wheat the correlations between varieties for different years were lower but mostly significant. For the winter barley differences between varieties were less, but even so differences between varieties in different years were significant. For oats differences between the varieties were small and there was no significant correlation within varieties between years. The results suggest that the nutritive value of cereal straws is generally consistent between years and is a characteristic that could be improved by selection.
Expected consequences of the segregation of a major gene in a sheep population in relation to observations on the ovulation rate of a flock of Cambridge sheep
Authors: Owen J. B. , Whitaker C. J. , Axford R. F. E. , Ap Dewi I. 
Published: September 2010

ABSTRACTA simple model was derived relating the phenotypic effect (g) of a major gene to observed values of the population mean and variance for a trait, at specified values of the major gene frequency and at specified basal values of the population mean and variance (in the absence of the major gene). This model was applied to a total of 549 observed values of ovulation rate in ewes of the Cambridge breed at Bangor under a range of assumptions. The mean values of ovulation rate were 2·44 for 243 ewes of 1 year of age and 37·54 for 306 ewes of 2 and 3 years of age with a coefficient of variation for both age sets of 0·50.The results indicate a minimum value for g, in this data set, of 1·07 for 1 year old and 1·72 for 2 and 3 year old ewes. The results are also consistent with a frequency value in the region of 0·3 to 0·4, with the absence of dominance and with a reasonable concordance with Hardy-Weinburg equilibrium. The results also indicate that the value of g varies according to the background phenotype since it is lower for younger as compared with older ewes.
Changes in the body composition of beef cattle during compensatory growth
Authors: Wright I A. , Russel A. J. F. 
Published: September 2010

ABSTRACTForty-two weaned suckled Charolais-cross steers were used to measure changes in body composition during compensatory growth in growing cattle. Six cattle were slaughtered initially and the remaining 36 allocated to either a low level of feeding to 350 kg live weight followed by a high level (LH) or a high level of feeding throughout (HH). Above 350 kg live weight, food intake on both treatments was the same at any given live weight. Six cattle were slaughtered from each treatment at 350, 400 and 450 kg live weight. From initial live weight (259 kg) to 350 kg, live-weight gains were 0·45 and 0·78 kg/day for the LH and HH treatments respectively (P < 0·001). From 350 to 400 kg live weight, live-weight gains were 1·35 and 0·98 kg/day (P < 0·01) for the LH and HH cattle respectively, while from 400 to 450 kg live weight there was no significant difference (1·38 v. 1·20 kg/day). The LH cattle contained less fat in the empty body than the HH cattle at 350 kg (118 v. 153 g/kg; P < 0·05) and 400 kg live weight (117 v. 169 g/kg; P < 0·01), but at 450 kg there was no significant difference between treatments. From 350 to 400 kg live weight the composition of the empty body-weight gain was 663 g water, ' 108 g fat and 216 g protein per kg in the LH cattle and 422 kg water, 311 g fat and 173 g protein in the HH cattle. From 400 to 450 kg live weight the equivalent figures were 491, 291, 156 g/kg for the LH cattle and 744, 67 and 203 g/kg for the HH cattle. The results demonstrate that following a period of food restriction the empty body-weight gain of cattle initially comprises increased proportions of protein and water and a reduced proportion of fat compared with unrestricted cattle when both are given the same amount of food and compared at the same weight. There then follows a second phase in which the proportion of fat increases and the proportions of protein and water decrease.