bluuebunny/crossref_metadata_2025_split huggingface dataset:
A note on the energy cost of walking in cattle
Authors: Ribeiro J. M. de C. R. , Brockway J. M. , Webster A. J. F. 
Published: September 2010

SUMMARYMeasurements were made of the heat production of cattle while standing at rest or walking on a treadmill at different speeds, both on the level and at a gradient of 6°. The energy cost of horizontal locomotion was about 2 J/kg per m at speeds of 40 to 85 m/min, irrespective of body weight or plane of nutrition. The energy cost of vertical locomotion was about 26 J/kg per vertical m.
Estimations of heterosis in crossbred dairy cattle
Authors: Donald H. P. , Gibson D. , Russell W. S. 
Published: September 2010

SUMMARYIn a long-term experiment, the performance of British Friesian, Ayrshire and Jersey cattle and their first and second crosses was evaluated over 526 first and 477 second lactations. Live weight at 18 mo of age and the ratios of lactation yield to live weight were examined as well as milk yield and composition of milk.Percentage heterosis in each combination of two pure breeds was estimated. For the three first crosses combined, heterosis for 305-day milk yield averaged 6·4% in first and 3·7% in second lactations. Heterosis in live weight at 18 mo averaged 2·9%; none was found in the Ayrshire × British Friesian crosses, but the others averaged 4·7%. Second crosses overall had an average live weight near to that of first crosses, but their milk yields were lower and, in the combined lactations, approximately equalled the purebreds' total.Components of variance due to breed and environmental factors were calculated. Breed accounted for 50% of variance in live weight at 18 mo but less than 10% of variance in milk yield.The influence of fertility on heterosis is discussed with reference to earlier findings, and economic implications are considered.
On fitting curves to lactation data
Authors: Cobby J. M. , Le Du Y. L. P. 
Published: September 2010

ABSTRACTThe usual method of fitting the model y = Anb exp(−cn) to lactation data, by a multiple regression of logey on n and logen, can result in an ill-fitting curve. An analysis of the untransformed data provides a better fit but requires more extensive computation and a simple approximation to this procedure is given. Since the parameters of this model have no direct biological interpretation two alternative models are introduced, each having a parameter measuring the persistency of lactation.
A note on the performance of fattening steers implanted with zeranol under grazing and feedlot conditions in Botswana
Authors: Shorrock C. , Capper B. S. , Light D. , Mlambo M. M. J. 
Published: September 2010

ABSTRACTTrials involving a total of 401 steers were carried out from 1974 to 1976 to determine the effect of implantation with zeranol on the performance of fattening steers under grazing and feedlot conditions i n Botswana.Over a 180-day grazing period in 1974, 1975 and 1976 there was a significant improvement in live-weight gain of 11·9, 24·5 and 12·3% i n implanted steers over control steers. Under feedlot conditions there was a mean improvement in live-weight gain of implanted steers over control steers of 17·9% over an average stay in the feedlot of 95 days.
Free-choice feeding of cattle on swedes and grass silage
Authors: Petchey A. M. , Mohammed H. H. 
Published: September 2010

ABSTRACTIn a trial of a changeover design, 12 British Friesian castrates (steers) were offered both grass silage and crushed swedes (Brassica napus) ad libitum so that they could show their preference for these feeds on a free-choice basis. Two additional dietary treatments were provided by the supplementation of either swedes or grass silage with 2 kg of rolled barley. Steers consumed 0·32 of their dry-matter intake as silage when offered a free-choice of crushed swedes and grass silage. Supplementing the diet with 2 kg of rolled barley significantly increased daily dry-matter intake but the increase was not affected by the location of the supplement, on either the silage or the roots.
Studies on a selection index for improvement of litter weight in sheep
Authors: Martin T. G. , Smith C. 
Published: September 2010

ABSTRACTThe value of a selection index for 8-week litter weight as a trait of the ewe, combining information on the ewe and on five classes of female relatives, was considered. Adding records on the dam and on paternal half sibs to those of the ewe gives increases of 10 to 50% in the rates of genetic response. The index can be simplified with little loss in efficiency by weighting all records equally for relatives with 1, 2 or more records within each class of relative. In selecting breeding replacements, information on the parents of the sire of the individual being selected may increase the rates of response by a further 20 to 30 %.
Growth and gastric abnormalities in the growing pig resulting from diets based on barley in differing physical forms
Authors: Lawrence T. L. J. , Thomlinson J. R. , Whitney J. C. 
Published: September 2010

ABSTRACTSeventy-two Large White × (Large White × Landrace) weaner pigs in each of three experiments were scale-fed diets containing 850 g barley per kg which had been processed by either cold rolling (R) or grinding through 1-56 mm (O) or 468 mm (T) screens. In experiments 1 and 2 barley (0-868 dry matter) was used and group feeding was practised for 55 and 100 days respectively. In experiment 3 barley (0-838 dry matter) was used and individual feeding was practised for 107 days. In experiment 1 gastric pH was recorded at slaughter. In all experiments the stomachs of all pigs were examined for gross and histological abnormalities.In experiments 1 and 2 growth rates and efficiencies of feed conversion were not significantly different for pigs fed the R-, O- and T-based diets. In experiment 1 the pH in the pylorus, but not in the fundus, was significantly higher in pigs fed the O-diet compared with the T-diet, and on the T-diet compared with the R-diet. Growth rates and efficiencies of feed conversion in experiment 3 were significantly poorer in pigs fed the R-diet compared with the T-diet, and on the T-diet compared with the O-diet. In experiment 1 one pig from each of the three diets showed hyperplastic changes in thepars oesophageaof the stomach. In experiment 2 no gastric abnormalities were found, but bile staining was present in the pyloric zone of one pig fed each of the three diets. In experiment 3 hyperplastic lesions of thepars oesophagea(and bile staining) were present in 19 (14), 10 (7) and 4 (1) pigs fed diets O, T and R respectively.
A note on the effects of boar presence on the performance of sows and their litters when penned as groups in late lactation
Authors: Petchey A. M. , English P. R. 
Published: September 2010

ABSTRACTWhen sows and their litters were grouped 21 days after farrowing, the introduction of a boar 4 days later stimulated lactational oestrus in only 2 of the 21 sows (seven groups of three sows and litters) exposed to the boar, while none of the sows in the control groups showed lactational oestrus. The boar presence in lactation affected the subsequent weaning to first service interval. This interval was 228 days for the sows exposed to a boar and 10·0 days for the control groups, the difference approaching significance (0·05<P<0·10). None of the sows in the boar treatment groups had a weaning to oestrus interval exceeding 9 days.
A note on the estimation of economic values for selection indices
Authors: Thompson R. 
Published: September 2010

ABSTRACTA procedure has recently been developed for estimating economic values which employs a profit function implying that animals with mean values for variates in the profit function give the most profit. However, the proposed index selects extreme animals, a paradox which is explained by showing that the index is appropriate for only part of the profit function. More appropriate selection indices are developed and illustrated graphically.
The effect of wilting and short-chopping of grass on the subsequent voluntary intake of silage, and live-weight gain of calves
Authors: England P. , Gill M. 
Published: September 2010

ABSTRACTFour silages were prepared from perennial ryegrass. Half the crop was picked up soon after mowing and the remainder left to wilt for 24 h. Half the unwilted and half the wilted grass was chopped by a forage harvester with its normal complement of knives; the remainder was chopped by a forage harvester with all but two of its knives removed. The ensiled material was offered ad libitum for 80 days as the sole food to 32 British Friesian male castrates initially 14 weeks of age and 111 kg live weight.Wilting raised silage dry-matter content by 31 g/kg fresh weight and gave lower concentrations of acetic acid whilst short chopping gave lower butyric acid. Concentrations of acetic acid, butyric acid and ammonia nitrogen were high on all treatments. Organic matter digestibility was significantly increased by wilting (P < 0·001) and significantly depressed by chopping (P < 0·001). There was no response in dry-matter intake to short chopping, but wilting raised daily intake from 18·4 to 19·9 g silage dry matter per kg live weight (P < 0·001). Live-weight gain was increased from 0·42 to 0·46 kg/day by short chopping (P < 0·05) and from 0·40 to 0·48 kg/day by wilting (P < 0·01)
The energy and nitrogen metabolism and performance of pigs infected with Oesophagostomum dentatum
Authors: Stewart M. , Holmes C. W. , Smith W. C. , Charleston W. A. G. 
Published: September 2010

ABSTRACTThe effect of Oesophagostomum dentatum on the performance of growing pigs over the live-weight range 20 to 80 kg was investigated. Fourteen individually-penned pigs in Experiment 1 and 16 group-penned but individually fed pigs in Experiment 2 were orally dosed once with 80 000 or 20 000 larvae respectively at about 18 kg live weight. Worm-free but otherwise similar pigs served as controls. Three energy and nitrogen balance studies were undertaken in two open-circuit calorimeters on four infected gilts and their paired worm-free counterparts on two levels of feeding at 7, 21 and 49 days after infection. Worm burdens averaging 4 255 and 4 722 in Experiments 1 and 2 respectively were recorded post mortem but performance and carcass measurements were not affected, neither were there any clinical symptoms. No significant differences between infected and worm-free pigs were recorded for either apparent digestibility of nitrogen and gross energy or for nitrogen retention. Possible reasons for the lack of measurable effects on pig performance are discussed.
The influence of wilting and season of silage harvest and the fat and protein concentration of the supplement on milk production and food utilization by lactating cattle
Authors: Peoples A. C. , Gordon F. J. 
Published: September 2010

ABSTRACTThis study was designed to examine the influence of pre-wilting and season of harvesting of silage on milk production and food utilization by dairy cattle and also the response to protein and fat concentration of the supplement given with silage. Twenty-four lactating British Friesian cows were used i n a four-period, partially balanced, change-over design experiment to evaluate 12 treatments consisting of three silage types (spring harvest unwilted (lUnW), autumn harvest unwilted (3UnW) and autumn harvest wilted (3W), each offered in addition to supplements containing both two crude protein levels (160 and 210 g/kg fresh weight) and two levels of inclusion of a fat supplement (0 and 100 g/kg fresh weight) in a 3 × 2 × 2 factorial arrangement. All supplements were offered at the same rate of 6·8 kg/day. Total diet digestibility and food utilization studies were carried out on all animals at the end of the third and fourth experimental periods.The wilted silage (3W) had a higher digestibility than the unwilted (3UnW) material and animals offered 3W silage consumed proportionately 0·18 more silage DM and produced 1·6 MJ/day more milk energy output than those offered 3UnW. The total ration digesibility and food utilization data showed the animals given the 3W silage consumed 13·5 MJ more metabolizable energy (ME) per day than those offered the 3UnW silage and were less efficient at converting the ME available for production into milk energy output than those given the 3UnW silage (efficiencies were 0·58 and 0·53 for 3UnW and 3W silages respectively).There were no differences between the digestibilities of the spring (lUnW) and autumn (3UnW) silages with the concentrations of digestible organic matter in the dry matter (DM) being 650 and 648 g/kg respectively. However, animals offered lUnW silage consumed proportionately 0·12 more DM and produced 1·05 kg/day more fat-corrected milk than those given 3UnW silage. The food utilization data indicated that this milk production difference could be accounted for by the higher ME intake on lUnW and that the efficiencies of conversion of ME available for production to milk energy output were similar with both seasons of harvests (efficiencies were 0·57 and 0·58 for lUnW and 3UnW respectively).Increasing the crude protein concentration of the supplement from 160 to 210 g/kg increased silage DM intake, milk yield and milk energy output by 0·2 kg, 0·66 kg and 1·9 MJ/day respectively with the response being greatest with lUnW and least with 3UnW silage. Increasing the fat concentration of the supplement depressed silage DM intake but increased milk yield by 0·53 kg/day.The effects of the treatments on total diet digestibility, energy and nitrogen utilization, and the volatile fatty acid concentrations of rumen fluid are also given.
The evaluation of automatic probes in Spain for the new scheme for pig carcass grading according to the EC regulations
Authors: Diestre A. , Gispert M. , Oliver M. A. 
Published: September 2010

ABSTRACTAn evaluation of three automatic recording probes, the Fat-o-Meater (FOM), the Hennessy Grading Probe II (HGP) and the Destron PG-100 (DST) was carried out for use in the revised European Community (EC) Pig Grading Scheme. One hundred and forty-five pig carcasses were selected from four abattoirs covering the national fatness distribution. Two fat thickness depths, one at the head of the last rib (LR) and the other at the 3rd/4th from the last rib (3/4LR fat), and one muscle depth (3/4LR muscle) taken in the same operation for recording 34LR fat were studied as predictors of EC reference lean concentration. All measurements were taken 60 mm from the dorsal mid line. The corresponding cut surface measurements were also recorded and the carcasses were dissected. The prediction of cut surface fat depths from fat depth probes was better than the prediction of cut surface muscle depth from muscle depth taken with the probes. The DST fat measurement predicted more accurately the corresponding cut surface measurements and FOM muscle depth was more precise in predicting muscle cut surface depth. The DST was better in the prediction of EC reference lean concentration with 3/4LR fat and 3/4LR muscle as predictors (residual s.d. 23·1 g/kg). By adding LR as a third independent variable FOM predicted slightly better the lean concentration (residual s.d. 22·3). For Spain, the equations with these three independent variables were submitted to the Pig Management Committee of the EC. All the methods tested predicted EC reference lean concentration with a residual s.d. less than 25 g/kg and a correlation higher than 0·8.
The effect of body reserves at farrowing on the reproductive performance of first-litter sows
Authors: Mullan B. P. , Williams I. H. 
Published: September 2010

ABSTRACTThe level of body reserves in first-litter sows was manipulated by giving gilts one of three levels (high (H), medium (M) or low (L)) of food from selection (44 kg live weight) to parturition. The aim of this experiment was either to maintain or to mobilize these reserves during lactation (31·4 days) by feeding sows to appetite (high (H)) or 2·0 kg/day (low (L)).When the level of body reserves was increased prior to farrowing (171 kg live weight, 32 mm backfat) sows had a lower voluntary food intake during lactation than those animals that farrowed with a low level of body reserves (126 kg live weight, 20 mm backfat) (H-H v. L-H, 3·4 v. 4·9 kg/day; P < 0·001). Both groups had a normal return to oestrous activity after weaning (mean interval between weaning and mating of 14 days) but the heavier animals mobilized more of their body reserves (H-H −30·7 kg live weight, -4·3 mm backfat; L-H -3·6 kg live weight +0·9 mm backfat; P < 0·001). When food intake during lactation was restricted to 2·0 kg/day the interval between weaning and mating was increased by 50% regardless of the level of body reserves present at farrowing. For the same animals, there were insufficient body reserves to support milk production at the same level as for those animals given food t o appetite.
Genetic and environmental influences on beef cattle production in Zambia 4. Weaner production from purebred and reciprocally crossbred dams
Authors: Thorpe W. , Cruickshank D. K. R. , Thompson R. 
Published: September 2010

ABSTRACTEstimates of dam reproductive performance are reported for purebred Africander, Angoni, Barotse and Boran dams, and the reciprocal crossbreds of the latter three breeds, under ranching conditions in Zambia.Mean performances based on a maximum of 1996 records collected over six parities were: calving rate, 65·6%; weaning rate, 62·8%; calf birth weight, 26·6kg; calf weaning weight, 163·6kg; and dam live weight at weaning, 363 0 kg.Purebred Africander and Barotse dams had significantly poorer calving rates, 542 and 57·6% respectively, than the purebred dams of the Angoni and Boran breeds, 69·1 and 66·0% respectively. Reciprocal crossbred dams of the latter two breeds had the highest calving rates, 71·2 and 74·4%. Heterosis estimates for calving rate were 0·8% for Angoni/Barotse crosses, 7·8% for Angoni/Boran crosses and 10·3% for Barotse/Boran crosses and, for weaning rate, 3·7, 6·7 and 11·5% respectively. There were no differences between reciprocal crossbred dams for calving and weaning percentages. The mortality rate of calves born to crossbred dams was 40% and that of the calves born to purebred dams of the same breeds 4·7%. Dam status at mating had an important effect on fertility with the calving rate of dams dry at mating, 89·1%, contrasting with a rate of 39·8% for those dams that were lactating at mating and that had calved late in the season.There were large differences between breeds for calf weights but heterosis estimates were small and nonsignificant. There were no differences between the progeny weights of reciprocal crossbred dams. Sex, date and period of birth, and dam status had significant effects on calf weights.Africander dams had the heaviest, and Angoni dams the lightest, live weights at weaning, 421·1 and 320·7 kg respectively. Heterosis estimates for dam live weights were small and non-significant, and reciprocal crossbred differences were unimportant. Dams which lost most live weight during the dry season, that had extremely light live weights at the beginning of the breeding season or that gained little weight during the breeding season had significantly poorer fertility than other dams.Overall estimates of heritability derived by dam/daughter regression were 0·20 for calving percentage, 0·76 for calf birth weight and 0·72 for calf weaning weight.
The effects of concentrate supplements on the performance of dairy cows offered grass silage ad libitum
Authors: Laird R. , Leaver J. D. , Moisey F. R. , Castle M. E. 
Published: September 2010

ABSTRACTNinety-six lactating British Friesian cows were offered ad libitum two grass silages having the following analyses: 181 and 241 g dry matter per kg fresh weight, 108 and 96g digestible crude protein per kg dry matter and 617 and 619 g digestible organic matter per kg dry matter. In addition, four concentrate supplements were offered, containing either 360 g crude protein per kg on an air-dry basis and given at the rate of 015 kg/kg milk or 180 g crude protein per kg given at the rate of 030, 0375 and 0·45 kg/kg milk. Large and highly significant differences were recorded in silage intake, mil yield, milk composition, live weight and condition score during the winter feeding period. These differences in performance were associated more with differences in energy than in protein intake. During the post-experimental grazing period no significant differences between treatments were recorded in milk yield and composition, with the exception of fat concentration, and by midsummer no significant differences were apparent in live weight. The results of the experiment were appraised in economic terms and implications for commercial practice discussed.
A note on the growth of Beefalo crossbred calves in Botswana
Authors: Makobo A. D. , Buck N. G. , Light D. E. , Lethola L. L. 
Published: September 2010

ABSTRACTIn a trial to evaluate the growth of crossbred calves under semi-arid ranch conditions in Botswana, pure Tswana and crossbred beef cows were inseminated with Beefalo and Italian semen or mated naturally with Brahman, Simmental or Tswana bulls. The 424 calves produced were weighed at birth and at monthly intervals t o 18 months of age.Beefalo crossbred calves were significantly lighter at birth than all other calves (P<0·05). At weaning (7 months) Brahman-sired calves were significantly heavier than Tswana calves, but no heavier than the other breed types. At 18 months of age Brahman, Italian and Simmental crosses were all significantly heavier than Tswana calves (P<0·05), but there was no significant difference between Beefalo crossbred and pure Tswana calves.These results indicated that the Beefalo cross had no advantage over the indigenous Tswana breed and more-conventional breeds were superior when crossed with the Tswana.
The frequency of cows served twice which remain pregnant to first service: a study of results from parentage tests
Authors: Rendel J. , Bouw J. , Schmid D. O. 
Published: September 2010

In 1,347 parentage cases in cattle it was determined whether conception resulted from the first or second service. Among cows served twice within short intervals (1–11 days) about 20% remained pregnant from the previous service. At an interval of one day this proportion amounted to 37%.About three-quarters of the cows had service intervals of 18–24 days. In most of these the calving took place between the expected dates according to the two services. In 6% of the cases with intervals of 18–24 days pregnancy resulted from the first service. It was estimated that about 1% of all cows mated twice within these intervals had become pregnant from the first service.Rules are suggested for when blood grouping should be required for registration of pedigrees in the herd book.