bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship of post-partum interval in mature beef cows with nutritional environment, biological type and serum IGF-1 concentrations
Authors: Nugent R. A. , Jenkins T. G. , Roberts A. J. , Klindt J. 
Published: September 2010

AbstractMature cows of nine breeds were fed (four cows per level within breed) at either 0·55, 0·71, 0·88 or 1·05 MJ metabolizable energy (ME) per kg initial body weight0·75 per day during non-lactational periods for an average of 4 years. During lactation, energy allowances were increased by 0·17 MJ ME per kg body weight0·75 per day. Breeds represented four biological types: moderate genetic potential for milk yield and growth (Angus, Hereford, Red Poll), moderate milk and high growth (Charolais, Eimousin), high milk and moderate growth (Braunvieh, Pinzgauer) and high milk and growth (Gelbvieh, Simmental). The objective was to test the effects of biological type and nutritional environment on length of post-partum interval as determined from serum progesterone levels. The potential of serum insulin-like growth factor-1 (IGF-1) level at 3 weeks post partum for predicting the length of the post-partum interval was also evaluated. Non-parametric statistical analyses appropriate for right-censored survival data were used to test effects on post-partum interval because collection of serum was terminated prior to ovulation in some cows.Energy availability × biological type effects on post-partum interval were significant. Increased energy availability tended to decrease post-partum interval in all biological types with high potential growth types exhibiting the greatest positive response to increased food. Post-partum interval for types with high growth potential was shorter within food level when associated with high rather than moderate potential for milk yield. Serum IGF-1 was related to post-partum interval at lower energy availability but appeared to have limited usefulness for identifying cows with extended intervals. Inherent direct and maternal production potential interact with available food resources to influence the post-partum interval of mature beef cows.
Genetic variation in measures of food efficiency in pigs and their genetic relationships with growth rate and backfat
Authors: Mrode R. A. , Kennedy B. W. 
Published: September 2010

AbstractData on 3783 Yorkshire, 2842 Landrace and 937 Duroc littermate pairs of boars, station tested between 1976 and 1989, were used to measure genetic parameters of average daily gain (ADG) from 30 to 90 kg, live backfat at 90 kg (BF), estimated lean growth rate (LGR), average daily food intake, food conversion ratio (FCR) and lean food conversion ratio (LFCR), as well as measures of residual daily food intakes over and above requirements for growth and lean growth. A method was developed to obtain restricted maximum likelihood estimates of genetic variances and covariances under an animal model when observations are on the means of sib pairs. Heritabilities of ADG, BF, LGR, FCR and LFCR were 0·43, 0·59, 0·39, 0·28 and 0·34, respectively. Heritability of daily food intake was 0·45, and heritability of measures of residual daily food intake ranged from 0·30 to 0·38. About half of the variation in daily food intake was residual (0·48 to 0·56). Genetic correlations of ADG with daily food intake, FCR and LFCR were 0·80, −0·28 and −0·09, respectively, and were small and positive (0·18 to 0·34) with measures of residual daily food intake. Backfat had genetic correlations of 0·42, 0·24 and 0·52 with daily food intake, FCR and LFCR, respectively, and genetic correlations between backfat and measures of residual daily food intake ranged from 0·15 to 0·61. Selection against residual food intake may be a useful means of improving efficiency of food utilization.
Accuracy in measuring cattle with special reference to identical twins
Authors: Taylor C. S. 
Published: September 2010

SUMMARYA study has been made of the relative accuracy of twelve linear body measurements of dairy cattle. The results of several repeatability trials are presented together with estimates of observer error derived from the routine measuring of identical twins. Various aspects of precision of measurement have been analysed. The accuracy found from any one trial can rarely be used as a reliable estimate of the accuracy of measuring in any subsequent experiment.The importance of observer error in identical twin studies has been assessed. It was found that from 10% to 70% of the total variation within pairs of uniformly treated identical twins could be due to measuring error. It was therefore concluded that in such studies, where observer error is a fairly large part of the total variation, a single routine repetition of every measurement would be advisable in long term experiments and several in the case of short term experiments with a small number of animals.Measurements have been ranked for relative accuracy and the ranking was found to be broadly similar on several different criteria: (a) relative to the variation within pairs of uniformly treated identical twins, (b) relative to the total variation in a population of unrelated animals and (c) relative to the mean size of the body part. The choice of measurements on the basis of relative accuracy is discussed.
The effect of method of rearing on the social behaviour of Scottish Blackface hoggets
Authors: Hunter R. F. , Davies G. E. 
Published: September 2010

SUMMARYFour groups of Scottish Blackface ewe lambs were reared in the period 11–52 weeks old under different regimes. The regimes differed in the age of the lambs at which they were separated from their dams and whether having been separated they were together in a field and/or penned together n i a sheep shed.These regimes caused differences in social behaviour among the four groups and also resulted in the groups adopting different parts (home ranges) of an enclosed 350 acre hill pasture. The various home ranges within the pasture are dissimilar environments and it is argued that home range and method-of-rearing effects will be confounded making statistical comparisons between the different rearing treatments impossible.
Heterosis in crossbred hill sheep
Authors: Donald H. P. , Read J. L. , Russell W. S. 
Published: September 2010

SUMMARY1. For ten years purebred Blackface and Swaledale ewes have been kept on a small hill grazing together with first crosses and backcrosses to the Swaledale. The total flock of about 120 ewes was mated and lambed on sown pastures where ewes with twins remained from lambing until weaning. Four new rams (two of each breed) were used each year.2. It is concluded that the Swaledales produced fewer lambs than the other ewes, but these were of greater birth weight (5 %) and cannon bone length (2 %); moreoever, they were better mothers than Blackface (4 %) when rearing singles on hill grazing but not if rearing twins on sown grass.3. Blackface sheep showed greater weights at weaning (5%), at mating (5%), and of fleece (15%) than did pure Swaledales.4. First cross sheep were equal to or slightly superior to the parental mean in birth weight, weaning weight and cannon-bone length. They exceeded the better parent in ewe weight, first fleece weight, and weight of weaned lambs.5. Backcross sheep although not always statistically distinguishable from Swaledale in cannon-bone length and fleece weight or from first cross sheep in reproductive characters tend to confirm the interpretations placed on the relations between the purebred and first cross sheep.6. Heterosis estimated as a superiority of first cross sheep over the mean of the two parental breeds varied from 0% for cannon-bone length to 9·5% for prolificacy of 4-year-old ewes.
Crossbred sheep production. III. Selection for growth rate and carcass attributes in the second-cross lamb
Authors: Bichard Maurice , Yalçin B. C. 
Published: September 2010

Results have been presented from a small scale investigation into operational and theoretical aspects of progeny testing Down rams as sires of crossbred fat lambs. Twenty-six Suffolk rams were evaluated from the growth records of 922 lambs out of Border Leicester × Cheviot ewes. In addition measurements were recorded on 260 carcasses. Significant differences were found between corrected progeny means, which were equivalent t o heritabilities of between 0·03 and 0·13 for live-weights up to 15 weeks, and o t higher values for skeletal measurements.A scheme for the selection of Down rams was considered which involved measuring the individual performance of all ram lambs and then progeny testing the best of these by measuring a fixed total number of crossbred lambs. It was concluded that the proportion to be progeny tested could be varied within quite wide limits without seriously changing the genetic merit of the selected group.
Effects of castrating lambs on growth and body composition
Authors: Bradford G. E. , Spurlock G. M. 
Published: September 2010

Effects of castration on growth, wool production, carcass characteristics, and meat quality in sheep were investigated.The experiment included two flocks (similar in their effect on pre-weaning performance, but representing high and low planes of nutrition after weaning), two years, and two slaughter ages. Rams weighed approximately 5 % more thanwethers at weaning, and 15 % and 23 % more as yearlings on the low- and high planes of nutrition respectively. Differences in favour of rams in terms of skeletal and muscle size and wool production were also greater on the higher plane of nutrition. Carcass weight was approximately 4%, 8% and 19% higher for rams among lambs, low plane and high plane yearlings, respectively. Proportion of carcass weight in the forequarters was 0·5 %, 1·1 % and 2·3 % higher for rams in these three groups. Rams had less kidney fat and the same percentage of the carcass weight in loin and trimmed leg as wethers in all groups.Carcass grade and eating quality as evaluated by a taste panel did not differ between ram and wether lambs. Among the lighter yearling group, meat from the loin of ram carcasses was less tender. Quality was appreciably lower for rams in the heavier yearling group. Meat from ram carcasses had 1 to 2% higher cooking loss than that from wethers.
The value of feather meal as a protein supplement for growing pigs
Authors: Barber R. S. , Braude R. , Chamberlain A. G. , Hosking Zena D. , Mitchell K. G. 
Published: September 2010

SUMMARYThe results of a nitrogen balance experiment with growing pigs have shown that 5 % feather meal was inferior to 7 % white-fish meal, when both supplements supplied the same amount of total crude protein in a barleyweatings- minerals-vitamins ration.A comparative feeding trial in which white-fish meal was partially replaced by feather meal in the diets given to growing pigs gave inconclusive results.
A note on variations in the level of aggression within a herd of goats
Authors: Syme G. J. , Syme L. A. , Jefferson T. P. 
Published: September 2010

SUMMARYChanges in the level of aggression in a restricted feeding situation were examined in a herd of goats with a stable dominance hierarchy. It was found that the number of butts occurring (the level of aggression) depended on both the nature and novelty of the various feeds presented. In general the highest number of butts and the lowest consumption were recorded on the first occasion that each feed was presented. The introduction of unfamiliar or highly desirable feeds to livestock may require special precautions if increased aggression is to be avoided.
Body size and conformation in sheep from birth to maturity as affected by breed, crossbreeding, maternal and other factors
Authors: Wiener G. , Hayter Susan 
Published: September 2010

SUMMARYBody weight was studied from birth to 5½ years of age and six linear measures of body size from birth to 4¼ years for sheep of five breeds, Scottish Blackface, Cheviot, Welsh Mountain, Lincoln Longwool and Southdown, and of crosses of these breeds with each other and with the Tasmanian Merino, but not in all possible combinations. The sheep were run as a single flock. Numbers ranged from 753 at birth to 150 at the end of the experimental period.There were marked differences among the breeds and crosses in all aspects of body size and some differences in rate of maturity. They also differed in conformation independently of body weight. Crosses of the hill breeds with the Lincoln and probably with the Southdown were heavier than the average of the parental breeds and larger in some linear body measurements from about weaning onwards. The weights of crosses of Blackface and Cheviot with Lincoln eventually exceeded those of the heavier parent of the cross. For the crosses among the three hill breeds only the Blackface Cheviot cross showed significant deviations from mid-parent values for weight and size.Maternal effects were important for all traits studied from birth to weaning and for weight up to a year old. In relation to mature size, Welsh dams produced the biggest and Lincoln the smallest lambs. The data did not permit Southdown maternal effects to be estimated. The effects of birth type and rearing were apparent for late maturing body parts up to a year old and for weight up to 3 years. Males, measured only from birth to weaning, were heavier and generally larger than females.Residual correlations between the various measures of size varied from 0·1 to 0·7.
A new net energy system for ruminants
Authors: Harkins J. , Edwards R. A. , Mcdonald P. 
Published: September 2010

SUMMARYA simplified Net Energy system for ruminants is described. It is based on the Metabolizable Energy system outlined by the Agricultural Research Council (1965) and enables a non-iterative approach to be used in the formulation of rations. The method is suitable for use in linear programming work and is illustrated, with appropriate tables, for growing cattle.
Behavioural relationships between Merino ewes and lambs during the four weeks after birth
Authors: Morgan P. D. , Arnold G. W. 
Published: September 2010

SUMMARYThe attachment between the ewe and her lamb, as assessed by estimating the distance between ewe and lamb and observing their behaviour, was studied for the 4 weeks after birth. The ewe and lamb kept in close contact throughout this period. They were within 10 metres of each other in 56% of all observations; only in 6% of all observations were they more than 50 metres from each other. With increasing age of lamb, the ewe spent more time grazing while the lamb also spent more time grazing and playing and less time sucking. The lambs showed independent forms of behaviour such as the formation of groups as they got older. The distinct dependent behaviour traits were that if bothewe and lamb were lying or walking, then they were usually close together.The mean distance between ewes and lambs remained constant for dependent forms of behaviour but gradually increased with age for independent forms of behaviour.
The effects of method of processing on the intake and digestibility by lambs of dried perennial rye-grass and tall fescue
Authors: Tetlow R. M. , Wilkins R. J. 
Published: September 2010

SUMMARYCobs and pellets which differed in particle size (modulus of fineness, MF) were prepared from dried perennial ryegrass and tall fescue and given to sheep. The MF values of the feeds were 2·45,1·09,0·81 and 0·74 for perennial ryegrass and 2·28,0·84,0·67 and 0·57 for tall fescue. Organic matter digestibility was similar for the two grass species when measured in vivo, but when measured in vitro values for perennial ryegrass were about 3 units higher than those for tall fescue. Voluntary intake and live-weight gain were higher for sheep given tall fescue, the difference in live-weight gain being just significant at P < 0·05. The response to change in particle size was similar for the two grass species. Intake was lowest and digestibility highest for the feeds with the highest MF, but differences between the three finely-ground forms of each species were not significant. There was a tendency for the intake of digestible organic matter to be lower for the feeds with lowest MF than for those with intermediate values for MF. The rate of passage of undigested particles was slower for cobs with the highest MF than for the other feeds, which did not differ significantly one from another.
Effects of plane of nutrition in late pregnancy on lamb birth weight and milk yield in early lactation of Chios and Awassi sheep
Authors: Louca A. , Mavrogenis A. , Lawlor M. J. 
Published: September 2010

SUMMARYTwo trials were conducted using two breeds of sheep varying in prolificacy but producing high commercial milk yields. In the first, 85 Chios ewes were assigned at 10 weeks before lambing to one of three planes of feeding: L, straw ad libitum; M, straw ad libitum + 0·5 kg concentrates; and H, straw ad libitum +1·0 kg concentrates. Six weeks prior to lambing, treatment L was stopped and all 85 ewes were re-randomized to treatments M and H. They were kept on these treatments until 14 days after lambing. In the second trial, 54 Chios and 56 Awassi ewes were allocated to the M and H treatments 6 weeks prior to lambing. After lambing they were fed ad libitum on straw and concentrates for 28 days.The mean metabolizable energy intake (Meal/day) over the 6-week period before lambing was 2·78 and 3·96 for Chios ewes in Trial 1, 2·39 and 3·51 for Chios ewes in Trial 2 and 2·66 and 3·72 for Awassi ewes in Trial 2, for the M and H treatments respectively.In both trials the treatment of the ewes affected the birth v/eight of twin and triplet lambs but not that of singles. In Trial 1, the differences in 14-day milk yield between treatments M and H were highly significant. In Trial 2, however, in which the ewes were fed ad libitum during lactation, no differences in the 14-day or the 28-day milk yields were observed for either breed. It is concluded that milk yields in early lactation are closely related to actual plane of nutrition in lactation but may also be affected by the body condition of the ewe at lambing, which may in turn be influenced by a low level of feeding in pregnancy.
Nutritional evaluation of wheat 1. Effects of preparation on digestibility of dry matter, energy and nitrogen in pigs
Authors: Ivan M. , Giles L. R. , Alimon A. R. , Farrell D. J. 
Published: September 2010

SUMMARY1. A split-plot design was used to study apparent digestibility of dry matter, gross energy and nitrogen of a whole grain wheat diet and processed (hammermilled, rolled or hammermilled and then steam-pelleted) wheat diets by eight small (33·9 ± 0·1 kg) and eight large (70±1·7 kg) pigs. Metabolizable energy and nitrogen retention were also studied with the small pigs.2. The processed wheat diets were superior to the whole grain wheat diet in all the parameters measured.3. There were no significant differences between the performance of pigs given the differently processed wheat diets.4. Apparent digestibility of dietary components particularly in the whole wheat diet was significantly higher when diets were given to small pigs than when given to large pigs.
Thyroxine and wool follicle activity
Authors: Ryder M. L. 
Published: September 2010

ABSTRACTSerum thyroxine levels were observed in 15 Soay ewes and seven rams for 1 year. From June to November the ewes had thyroxine concentrations 40% higher than the rams, and the level in both sexes increased from December to May, demonstrating a seasonal cycle in thyroxine level that could be associated with the annual wool growth cycle. To hasten the onset of wool follicle activity, nine Wiltshire sheep were given thyroxine implants in autumn when the follicles normally become inactive, but only a slight increase in follicle activity occurred. Eighteen Soay sheep were given thiouracil orally for 1 month in spring in an attempt to block a possible seasonal increase in thyroxine secretion that might be associated with the normal regrowth of wool, but no retardation of the spring regrowth was obtained.
A note on nutrition during late pregnancy in West African Dwarf sheep
Authors: Adut I. F. , Olaloku E. A. 
Published: September 2010

ABSTRACTThree groups, each of 12 West African Dwarf ewes weighing 17·5 kg at mating, had mean daily digestible organic matter intakes over the final 7 weeks of pregnancy of 249, 435 and 538 g/ewe (Treatments I, II and III respectively). Mean plasma concentrations in Treatments I, II and III were: glucose, 384, 527 and 538mg/l; non-esterified fatty acids (NEFA), 672, 441 and 427 μequiv/1; and ketones, 44·1, 30·5 and 27·3 mg/1. The differences in all metabolites between Treatment I and Treatments II and III were significant (i) <0·001). The mean birth weights of the single lambs from ewes in Treatments I to III were 1·1, 1·7 and 1·8 kg, those from ewes in Treatment I being significantly lighter than those from ewes in Treatments II and III. Lamb birth weights were significantly and positively related to energy intake and to plasma glucose concentrations, and significantly and negatively related to plasma NEFA and ketone concentrations.The results indicate that the effect of undernourishment during late pregnancy in West African Dwarf sheep may be greater than in European breeds, and that the concentrations of blood metabolites may have a use in monitoring and regulating nutritional state in this genotype.
Maize silage for milk production: The influence of concentrate supplementation and the effect of adding urea or ammonia before feeding
Authors: Aston K. , Daley S. R. , Tayler J. C. 
Published: September 2010

ABSTRACT1. Thirty lactating British Friesian heifers and cows were individually given maize silage ad libitum containing 331 g dry matter/kg, 13 g nitrogen and 11·2 MJ of metabolizable energy per kg dry matter. Urea or aqueous ammonia was mixed in at the time of feeding to give 7·0 g nitrogen per kg silage dry matter. Urea-treated silage was given with concentrates at a high (mean 6·6 kg dry matter/day: treatment HU) or a low (mean 3·3 kg:treatment LU) level of feeding; the lower level only was given with ammonia-treated silage (treatment LA).2. The addition of ammonia raised silage pH values from 3·9 to 4·4. Silage dry-matter intakes in lactation weeks 7 to 22 for treatments HU, LU and LA were 8·8, 11·1 and 10·7 kg/day.3. Digestible organic matter content in the dry matter of the diets measured in vivo was not significantly affected by treatment. However, digestible organic matter intakes were significantly greater for treatment HU than for LU in weeks 7 to 10, and for LU than for LA in weeks 11 to 22.4. The yields of milk and the contents of protein, lactose and energy did not differ between treatments. The milk yields for treatments HU, LU and LA in weeks 7 to 22 were 20·2,19·2, 18·8 kg/day respectively. Fat content of milk was significantly depressed with the HU treatment for heifers in weeks 7 to 10. The live-weight changes of the cows in weeks 7 to 22 for treatments HU, LU and LA were +0·10, −0·07 and −0·37 kg/day; the live-weight loss by cows given treatment LA was significantly greater than for LU. The live-weight change of the heifers was not affected by treatment.