bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of implantation of trenbolone acetate and oestradiol-17β in wether lambs at two initial live weights on concentrations of steroidal residues and blood glucose, urea and thyroid hormones
Authors: MacVinish Lesley J. , Galbraith H. 
Published: September 2010

AbstractThirty-two Border Leicester ♂ × Scottish Blackface ♀ wether lambs aged about 5 months were divided into two groups on the basis of live weight such that group Gl contained the 16 lightest lambs and group G2 the 16 heaviest. Lambs in group Gl were subdivided equally at random either to be sham-implanted controls (group C1) or to be implanted with 35 mg trenbolone acetate (TBA) + 5 mg oestradiol-17β (group T1) at 24 kg initial live weight. The lambs in group G2 were also subdivided into two groups (groups C2 and T2) and similarly treated approximately 1 month later at 37 kg initial live weight. The lambs were offered ad libitum a good-quality diet. They were slaughtered 60 days after implantation. Comparisons were made for the main effects of hormonal treatment and initial live weight.Concentrations in blood of 17-β-hydroxy-trenbolone (TBOH) and oestradiol-17β (OE) measured by radioimmunoassay peaked within 1 to 3 weeks after implantation and declined thereafter. Maximum concentrations and concentrations at slaughter respectively were 1·46 and 0·32 μg/l (group T1) and 0·78 and 0·28 μg/l (T2) for TBOH and 85 and 33 μg/1 (T1) and 59 and 37 ng/l (T2) for OE. Values up to week 7 were consistently greater in implanted animals in group T1 than in group T2. Hormonal implantation decreased the concentrations of total plasma triiodothyronine and thyroxine and urea and increased values for glucose up to week 5 or 6 after implantation. The animals in group G1 compared with G2 had, on average, variably lower concentrations in plasma of triiodothyronine, thyroxine, glucose and urea.The highest concentrations of solvent-extractable residues were obtained in samples of kidney and liver (up to about 500 ng/kg for TBOH and 180 ng/kg for OE) with intermediate levels for fat and lowest levels for muscle. Conjugated trenbolone ranging from 45 to 186 ng/kg was present in samples of kidney, liver and perinephric fat. Trenbolone acetate was detected only in samples of fat. Variable effects of live weight at implantation on residue levels were recorded.
Fatness, live weight and performance responses of sows to food level in pregnancy
Authors: Whittemore C. T. , Smith W. C. , Phillips P. 
Published: September 2010

AbstractSixty crossbred females received one of three pregnancy feeding rates over five parities: high (2·3 kg/day); medium (2·0 kg/day) and low (1·7 kg/day) to produce variation in body fatness and live weight. During a 32-day lactation all sows were fed the same allowance according to litter size. At the start of parity 5 ultrasonic P2 backfat depths for the high, medium and low treatments respectively were 11·2, 11·0 and 10·6 (s.e. 1·77) mm while live weight was 184, 177 and 167 (s.e. 8·6) kg. Averaged over five parities, backfat depths at conception were not significantly different between treatments. Sows given higher pregnancy feeding rates in pregnancy were heavier and fatter pre-partum but lost relatively more live weight and backfat during lactation. Regression coefficients for the slope of the relationship between total sow pregnancy weight (kg) and fatness (mm) change, and food intake (kg/day) were 0·2 and 0·04 respectively. Pregnancy feeding rate did not influence the number of live births but total litter weight at weaning was positively related to the weight and fatness of the sow at parturition and her subsequent rate of weight and fat loss during lactation (these characteristics of the sow also being positively related): live weight of litter at 32 days (kg) = 67 – 1·8 sow backfat change in lactation (mm) – 0·4 sow live-weight change in lactation (kg). Absolute sow live weight and fatness were positive influences on readiness to rebreed after weaning.
Selection in pigs for increased lean growth rate on a time-based feeding scale
Authors: McPhee C. P. , Rathmell G. A. , Daniels L. J. , Cameron N. D. 
Published: September 2010

AbstractSelection was carried out in a line of pigs for increased growth rate of lean tissue. The selection criterion was weight of lean in the ham predicted from live backfat and weight measurements after a 12-week performance test commencing at 25 kg live weight. All pigs were given the same total amount of food over the test period. The scale was set to about proportionately 0·85 of predicted ad libitum intake. Boars selected with an intensity of 1/12 were used for 6 months and sows selected with an intensity of 1/4 were kept for two farrowings. An unselected control line was maintained concurrently.After five generations, performances of selected and control line pigs were compared on ad libitum and scale feeding as they grew to 85 kg. Responses in the selected line on scale feeding were +51 g/day for growth rate (GR), −0·16 for food conversion ratio (FCR), −2·2 mm for backfat (F) and +0·47 kg for ham lean (HL). On ad libitum feeding, responses were much higher in the selected line, giving rise to line × food interactions. Responses were +128 g/day for GR, −0·27 for FCR, −2·3 mm for F, +1·01 kg for HL and +0·15 kg/day for food intake (FI). Estimates of the heritability of HL from variance components were 0·43 (s.e. 0·15) on scale feeding and 0·28 (s.e. 0·19) on ad libitum feeding. The realized heritability of HL on scale feeding was 0·29 (s.e. 0·04) and its co-heritabilities with the other traits on both feeding levels were of similar magnitude to its heritability. Scale feeding exposed genetic variation in the partitioning of food between lean and fat deposition and appeared to be a suitable selection regimen for performance on ad libitum feeding.
Effect of water sprinkling during the hot-dry summer season on semen quality of Holstein bulls in Saudi Arabia
Authors: Salah M. S. , El-Nouty F. D. , Al-Hajri M. R. 
Published: September 2010

AbstractTen Holstein bulls, 4 to 5 years old were used to study the effect of cooling the bulls on their semen quality. Five bulls were sprinkled with water for 15 min five times a day throughout a 6-week period of the summer season (hot-dry) in Saudi Arabia, and the other five bulls acted as the control and were not sprinkled with water. Semen quality was improved significantly during the cooling period. This improvement was evident from the significant increase in sperm motility (P < 0·01) and decrease in the percentage of both dead and morphologically abnormal (primary and secondary) spermatozoa per ejaculate of cooled bulls (P < 0·01). The effect of cooling was more marked through the last 3 weeks than during the first 3 weeks of the experimental period. Ejaculate volume, sperm concentration and hence total sperm counts did not differ significantly between the cooled and the non-cooled bulls. Concerning the type of abnormal spermatozoa, the overall secondary abnormality was higher than the primary in both the cooled and the control groups, with higher values for the control (P < 0·01). Only the mid piece showed higher primary defects than the secondary. The pyriform heads, the coiled mid pieces and tails and the bent tails were the main sources of variations (P < 0·01) in the incidence of sperm abnormality between the cooled and the non-cooled bulls. Cooling the bulls during the heat stress period also lowered their rectal temperature and increased blood haemoglobin level without affecting the packed cell volume
Effects of rapid inbreeding and of crossing of inbred lines on conception rate, prolificacy and ewe survival in sheep
Authors: Wiener G. , Lee G. J. , Woolliams J. A. 
Published: September 2010

AbstractThe effects of four generations of inbreeding, to achieve inbreeding coefficients (F) of 0·25, 0·375, 0·50 and 0·59, on conception rate, prolificacy, litter weight at birth and survival of breeding females, have been studied in sheep. Crosses of inbred lines were also examined. Three breeds, Scottish Blackface, Cheviot and Welsh Mountain, and the crosses among these breeds, were involved. Analyses were carried out both for the data overall and within inbred lines.Conception rate at the first oestrus at which the ewe was mated (in each year) declined almost linearly from 0·71 (F2generation - inbreeding F = 0·0) to 0·44 (F = 0·59) with line crosses showing 0·78 conception rate. The corresponding results following up to three rounds of services at successive oestrous periods were 0·91, 0·74 and 0·97 respectively. Analyses within lines showed a steeper rate of decline in conception rate to 0·33 (F = 0·59) following first services and 0·63 following up to three successive periods. This indicates that the lines with the best conception rates survived the inbreeding process better.Prolificacy, the number of lambs born per ewe lambing, dropped from 1·73 (F = 0·0) to 1·37 (F = 0·25) and thereafter more slowly to 1·24 (F = 0·59). Line crosses were no better than the initial non-inbred generation (F2and the purebred equivalent O2). Within-line analysis gave the same results.The effects of inbreeding on litter weight at birth mirror closely those for prolificacy.Ewe survival declined linearly with inbreeding. There was a 1·2-fold increase in the risk of death for every increase in the inbreeding coefficient (F) of 0·1 (analysed by using a proportional hazard model).In general, there were no significant differences between purebred and crossbred sheep in the effects of inbreeding. For conception rate, prolificacy and litter weight (for which the point was examined) the changes with inbreeding could not be explained, statistically, in terms of dominance alone, suggesting, therefore, that epistasis is also involved.
Bone distribution patterns in sheep selected for high and low weaning weight
Authors: Perry D. , Thompson J. M. , Butterfield R. M. 
Published: September 2010

AbstractThe change in the proportional distribution of bone weight within the carcass skeleton from birth to maturity was examined in rams and ewes from flocks of Australian Merino sheep selected for high (weight plus) and low (weight minus) weaning weight and from a randomly selected control flock. Data from 140 animals (106 immature, 34 mature) were used. Shape parameters for the long bones of the limbs in the 34 mature animals were derived by determining the allometric relationship between bone length, diameter and individual bone weight.Selection for increased and decreased weaning weight resulted in a concomitant increase and decrease in mature size and total bone weight. In the weight plus group, total bone as a proportion of body weight also increased but selection had little effect on the proportional distribution of bone weight within the skeleton at any stage of maturity. This was the product of similar growth patterns within the skeletal system aiming towards a similar mature distribution pattern for each strain.Within the strains of different mature size there was a difference between mature rams and ewes in both total bone weight as a proportion of body weight and in the proportional distribution of this bone weight. This was associated with differences in the maturing patterns of the bones of the hindlimb and the pelvic girdle.Neither selection nor sex affected the relationship between bone shape and bone weight, although the difference in bone weight between the strains and sexes at maturity meant that they also differed in bone shape at this point.
The effects of level of feeding of sows during pregnancy. I. Reproductive performance
Authors: Lodge G. A. , Elsley F. W. H. , MacPherson R. M. 
Published: September 2010

1. Twelve sets of 3 litter-sister Large White gilts were mated at first oestrus after reaching 250 lb. live-weight and given daily during 3 successive pregnancies either 6 lb. (A), 3 lb. (B) or 3 lb. for 76 days then 6 lb. until parturition (C) of the same meal mixture. During an 8-week lactation all were given 4 lb. meal plus 0·8 lb. per piglet suckled.2. There was a significant linear increase in numbers born with successive parities (P<0·05) but no significant differences between treatment or sister groups. There was a highly significant difference between treatment groups in mean piglet birth weight (P< 0·001) but no parity effect; mean birth weights were 2·76, 2·40 and 2·58 Ib. for Groups A, B and C respectively. Differences between sister groups in mean piglet birth weight were also significant (P<0·05).3. Post-natal litter performance was poor for all groups, probably because of the presence of E. coli, but there was no evidence of treatment effects other than on 3-week weight of third litters, which was significantly greater in Group C than in A or B (P<0·05). There were no significant effects on either number or weight of piglets at 8 weeks.
A mathematical model of the culling process in dairy cattle
Authors: Robertson Alan 
Published: September 2010

1. A mathematical theory of the culling process in dairy cattle has been developed. This was necessary to give a conceptual framework for the discussion of longevity in the dairy herd as a heritable character, of its genetic relationship with milk yield and of the effects of selection on the genetical analysis of yield itself.2. Culling is assumed to take place at the end of each lactation by truncation selection of a normally distributed variate (the culling variate) of which yield itself is a component.3. Expressions are then derived for the effect of the culling on various parameters of yield and for survival as a function of yield.4. The derivation of expressions relevant to progeny groups is dependent on the relative values of the genetic and phenotypic regressions of the culling variate on yield.5. Because little is known of the actual causes of culling, it is not permissible to predict the genetic gain in yield by multiplying the selection differential by the heritability. This is only justified if the genetic and phenotypic regressions of the culling variate on yield are equal.6. A direct estimate of the genetic gain by selection can, however, be obtained from the covariance for any character between the mean relative survival of progeny groups and their mean value for the character.7. The effect of culling on the genetic analysis of yield in later lactations is discussed, as is the effect of later culling on survival to later ages as a function of early yield. It is suggested that the regression coefficient of relative survival of progeny groups on heifer yield will be approximately linear with age whereas that of individuals will probably increase to a limiting value.8. The heritability of survival to different ages will probably pass through a maximum at the fourth lactation.9. Longevity itself, as a function of heifer yield, is the sum of the cumulative survival curves to each individual lactation. The regression of length of life on heifer yield, at the individual or at the progeny test level, can be related to the mean phenotypic and genetic selection applied to animals in the herd at any time.10. Because culling is to a large extent a voluntary action of the farmer, longevity in the dairy herd, though it is under continual selection and may have a significant heritability, need not necessarily increase.
Sexual maturity and spermatogenesis under heat stress in the bovine
Authors: de Alba Jorge , Riera‡ Simón 
Published: September 2010

Results are presented of an investigation in which 10 bull calves were subjected to heat stress in a climatic chamber from 26 weeks of age to the age of puberty. A similar group of 8 calves sired by the same bull were simultaneously subjected to ambient temperatures in another chamber. Maximum temperature in the hot chamber was 35–36° C. for 8 hours daily and maximum temperature in the temperate chamber was 27° C.Observations were made on weight and age at puberty and characteristics of the first five ejaculates obtained from each bull. Post-mortem examinations included: carcass weight, weight of all genital organs, measurement of sperm reserves in testicles and epididymides and histological observations of the seminiferous tubules. The results indicated that the hot temperature exposure retarded fertility but that libido was exhibited at essentially the same intensity by both groups. The quality of semen obtained and the concentration of the spermatozoa were much lower in the bulls subjected to the hot environment during their growth period prior to puberty. The poor quality of semen was associated with impaired spermatogenesis.It is recommended that in all fertility studies conducted with exotic breeds in the tropics, semen of known uniform quality be used. Natural service should not be used.
The nutrition of the early-weaned calf VI. The effect of supplemental lysine and methionine on the utilisation of groundnut protein
Authors: Preston T. R. , Whitelaw F. G. , MacLeod N. A. 
Published: September 2010

SUMMARY1. Nitrogen balance studies have been conducted on eight early-weaned calves receiving four diets containing, respectively, groundnut meal, groundnut+lysine, groundnut+lysine+methionine and white-fish meal as the major protein source.2. There were no significant differences between groundnut meal diets i n any of the measurements examined. On the fish meal diet all measures of nitrogen retention tended to be higher than the corresponding values for groundnut meals.3. Daily live-weight gains were significantly higher on the fish meal diet than on any of the groundnut diets (P<0·05).4. It is suggested that the supplementary amino acids, being highly soluble, were rapidly deaminated by rumen micro-organisms.
An analysis of pre-weaning deaths in rabbits with special emphasis on enteritis and pneumonia. I. Non-genetic sources of variation
Authors: Rollins W. C. , Casady R. B. 
Published: September 2010

Non-genetic sources of variation in pre-weaning death losses due to enteritis or pneumonia have been investigated using records of 15,329 rabbits born during the years 1946–61 in the random bred colony at the U.S. Rabbit Experiment Station at Fontana, California. Under consideration were periods of years, season within years, litter size, parity of doe, and fostering.For enteritis there was a statistically significant effect of season due to a negative regression of death rate on ambient temperature. For pneumonia, periods of years were statistically significant due to an increase in later years in deaths during the first 14 days of life. The other sources of variation studied were of negligible importance.
A comparison of the body size, fleece weight and maternal performance of five breeds of sheep kept in one environment
Authors: Wiener Gerald 
Published: September 2010

Female sheep of five breeds (Scottish Blackface (B), South Country Cheviot (C), Welsh Mountain (W), Lincoln Longwool (L), and Southdown (S)) were purchased as lambs of 5–6 months old and subsequently kept as a single flock on a grassland farm until they were 4½ years old (Southdowns to 3½ years). The sheep were used in a crossbreeding experiment with up to six breeds of ram.The sheep were weighed and 8 body parts measured at frequent and regular intervals. The Blackfaces and Southdowns grew, relative to their mature size, a little faster initially than the Cheviots. Mature weights (lb.) were approximately B: 146, C: 145, W: 101, L: 197 and S: 129. The breeds differed in conformation but the order of maturity of the body parts was the same for each breed. Variances for body measurements decreased slightly with increasing age for early-maturing parts and increased a little for later parts. The coefficients of variation decreased slightly with increasing age. Variance in weight increased markedly with age (but not the C.V.) and showed the only large breed differences in variance.Fleece weight, after the first shearing, was strongly affected by the amount of wool shed prior to shearing. Shedding differed significantly between the breeds, Cheviots shedding most. Shedding was also related to the number of lambs born per ewe. The total weights (lb.) of wool produced from four shearings were B: 23·2, C: 20·0, W: 15·6, L: 55·5 and S (estimated from 3 shearings): 20·8.The numbers of lambs born per ewe totalled over three lamb crops were B: 5·81, C: 5·21, W: 4·53, L: 4·85 and S (estimated from two crops): 4·55. In survival to weaning, single-born lambs were no better than twins and crossbred lambs no better than purebred. Lambs born to Welsh mothers had the best survival; the other breeds did not differ significantly from each other. The breeds of ewe differed in the proportions of their twin lambs which had to be assisted at, or soon after, birth.When each breed of ewe was mated to the same breeds of ram, the weights of lambs born to Blackface mothers did not differ significantly at birth from those of lambs born to Cheviots but were heavier at weaning. Lambs from Welsh mothers were the lightest at birth and weaning.In relation to (live-weight)0·73 the maternal performance of the Welsh females was at least as good as that of the Blackfaces but the wool production was slightly poorer.
The effects of environmental temperature and method of feeding on the performance and carcass composition of bacon pigs
Authors: Holme D. W. , Coey W. E. 
Published: September 2010

A trial designed to investigate the effects of two environmental temperatures, three feeding regimes and the interactions between them is described. A temperature of 72° F. was better than one of 54° F. for bacon pigs between 40 lb. and 200 lb. weight. The higher temperature resulted in faster growth, more efficient feed conversion and increased length of carcass. Other carcass characteristics were not significantly altered. Ad libitum feeding resulted in faster growth and fatter carcasses than restricted feeding, but did not have a significant effect on efficiency of feed conversion. When feed intake was restricted, feeding pigs once daily or twice daily resulted in similar performance and carcass composition.There was a significant interaction between environmental temperature and feeding method for average daily gain in that pigs fed ad libitum grew faster at the low temperature and pigs fed restricted amounts of feed grew faster at the high temperature. No other interaction reached significant levels.
Prediction of the voluntary intake of food by dairy cows: 2. Lactating grazing cows
Authors: Curran M. K. , Holmes W. 
Published: September 2010

SUMMARYIndividual observations made in different weeks of lactation (WL) of live weight (LW, lb), milk yield (MY and FCM, lb/day), age (years) live-weight change (LWC, lb/day) and digestibility of the organic matter consumed (D, %) were used to produce models pre-dicting organic-matter intake (OMI, lb/day), digestibleorganic-matter intake (DOMI, lb/day) and faecal output (lb OM/day) in 72 grazing cows (Analysis A). Estimates of herbage availability (HA, lb dry matter/cow per day) applicable to 44 of the cows, together with the above variables were used in a similar manner (Analysis B). The multiple regression methods of analysis were applied solely to between-cow observations by selection of a single set of data from the many available for each cow.FCM and LW0·73 gave better results than MY and LW, and together with age, were all significant variables for the prediction of the dependent variable. HA was not a significant source of variation, D was only effective in models of DOMI and faecal output, and stage of lactation was not considered a consistently useful variable. The application of the multiple regression technique to the problem of partition of nutrients and the prediction of intake is considered. Precision of prediction is discussed in terms of tolerance limits for predicted values, and it is concluded that the lack of accuracy of measurement of intake in the individual grazing cow is the major obstacle to the accurate prediction of intake in grazing cows.