bluuebunny/crossref_metadata_2025_split huggingface dataset:
A note on a simple criterion for choosing among sample joints for use in double sampling
Authors: Cook G. L. , Jones D. W. , Kempster A. J. 
Published: September 2010

ABSTRACTA simple criterion is described for selecting which of a number of sample joints estimates most precisely for a given cost (T) the mean lean percentage of a population of carcasses, using double sampling. It is shown that the best joint is the one giving the largest value of:where ρ is the correlation between the lean content of the sample joint and the lean content of a carcass side (y), and k is the cost of the sample joint dissection as a proportion of the cost of side dissection. The optimum proportion of carcasses to side dissect is:and the standard error of the estimated mean is then:where σyis the standard deviation of y and C is the cost of measuring y.
The voluntary intake and digestibility by cattle and sheep of dried grass wafers containing particles of different size
Authors: Wilkins R. J. , Lonsdale C. R. , Tetlow R. M. , Forrest T. J. 
Published: September 2010

SUMMARYWafers of dried grass which differed in particle size (modulus of fineness) were prepared and fed ad libitum to cattle and sheep. The response of the two classes of stock to the feeds was similar. The digestibility of organic matter and of cellulose decreased with decrease in modulus of fineness (more fine particles) and this was associated with more rapid passage of the finely-milled material through the alimentary tract. Organic matter intake generally increased with decrease in modulus of fineness, but the pattern of response differed between experiments. In one experiment the difference in voluntary intake between feeds with modulus of fineness of 2·5 and 1·0 was less than 5% and not significant, but in a second experiment the intake of feed with modulus of fineness of 2·1 was 18% lower than that of feed with modulus of fineness of 1·0. In the first experiment the wafers broke down during handling and feeding with the result that the feed of low modulus of fineness was extremely dusty, but in the second experiment a binding agent was included and little breakdown of wafers occurred. It is suggested that dustiness may have restricted the intake of some of the feeds in the first experiment. Intakes of digestible organic matter did not differ significantly between treatments in either experiment.
Photoperiodism in the ewe 5. An attempt to induce sheep of three breeds to lamb every eight months by artificial daylength changes in a non-light-proofed building
Authors: Ducker M. J. , Bowman J. C. 
Published: September 2010

SUMMARYAn attempt to induce ewes to lamb at intervals of 8 months using high levels of artificial daylength applied in a non-light-proofed building was carried out over a period of 2½ years.Thirty each of Dorset Horn, Clun Forest and Kerry Hill ewes were used. There were two different light regimes, both involving abrupt changes in daylength, all of which occurred at daylengths in excess of natural daylength. In both treatments the artificial daylength was abruptly increased to 22 hr at conception. In one treatment there was an abrupt decrease in daylength at parturition whilst the other treatment was an abrupt decrease in daylength approximately 50 days before parturition. The size of the daylength decrease possible was determined by the natural daylength at the time the decrease was applied and at the estimated time of onset of next oestrus.The majority of ewes lambed four times in the 2½ year period, parturition occurring in March-April 1969, December 1969-January 1970, September-October 1970 and May 1971. The Clun Forest ewes produced 38, 29, 20 and 22 lambs at the four lambings, whilst the Dorset Horn ewes produced 41, 35, 26 and 25 lambs at the four lambings. Only 11 of the Kerry Hill ewes lambed throughout the whole experiment producing 3, 5,0 and 7 lambs at the four lambings. It is suggested that the changes in daylength at these high levels controlled the breeding activity of the ewes.
An evaluation of beef carcass quality 2. Influence of variation in grazing intensity and the level of barley supplementation with silage on the carcass and meat quality of Friesian steers
Authors: Hinks C. E. , Prescott J. H. D. 
Published: September 2010

SUMMARYTwo experiments concerning the effects, on the carcass and meat characteristics of 18-months-old Friesian steers, of variation in grazing intensity and the level of barley feeding with silage are reported.Groups of 12 steers were grazed at different intensities over 5-month grazing periods, such that live-weight differences of 38 kg and 16 kg were recorded at housing. No compensatory growth was recorded during the subsequent winter feeding period.Whilst the grazing treatments had little effect on carcass or meat quality, higher levels of barley feeding with silage over the winter period (710v.410 kg/steer) had significant effects on live-weight gain, and increased carcass weight by 21 kg at slaughter. The higher yield of carcass weight was reflected in significant differences in carcass composition, joint proportions and retail cut-out value. Sixty per cent of the carcass weight difference was removed as trim fat. Differences in carcass fatness were not associated with any differences in eating quality.
Milking ability in relation to size and shape of teats
Authors: Ovesen E. 
Published: September 2010

SUMMARYLength and diameter of teats were measured on first-lactation cows at Danish progeny testing stations. The cows were also classified into four groups according to shape of teat and teat tip. All traits were corrected for yield level and interval after calving and correlated with milking characteristics. The conclusions drawn were:1. Teat length influences both average rate of milk flow and yield on hand stripping. The most satisfactory milking is obtained in cows with short teats. In Red Danish, Black and White Danish and Jersey cows, respectively, desirable length of fore teat is ≤ 6, ≤ 6, and ≤ 5 cm, and of rear teat about 1 cm shorter.2. Teat diameter is of no significant importance to average rate of milk flow, but yield on hand stripping is most satisfactory when the diameter is ≤ 2·4 cm.3. Teat shape must be very extreme before an adverse influence is recorded on average rate of milk flow and yield on hand stripping.4. The milking characteristics of cows are correlated with shape of the teat tip. The highest rate of milk flow and the lowest yield on hand stripping is found in cows with flat and concave teat tips.5. A relationship exists between teat length and the shape of the teat tip, and partial correlation coefficients show that of the teat traits investigated the most important factor affecting average rate of milk flow is the shape of the teat tip whilst teat length—similar to the effect of teat diameter—is of greater importance to the yield on hand stripping. Investigations into the possible consequences for udder health must, however, be conducted before selection for a special shape of the teat tips is introduced.
Seasonal variation in oestrus and ovarian activity of Finnish Landrace, Tasmanian Merino and Scottish Blackface ewes
Authors: Wheeler A. G. , Land R. B. 
Published: September 2010

SUMMARYThe patterns of seasonal variation in reproductive activity were observed over a period of 15 mo for approximately 15 females of each of three breeds: Finnish Landrace (Finn), Tasmanian Merino (Merino) and Scottish Blackface (Blackface). The incidence of oestrus was measured by teasing with vasectomized rams, and the incidence and rate of ovulation were determined frequently by laparoscopy. Luteal function was assessed from peripheral venous blood progesterone concentration on days 7 and 11 of the oestrous cycle. Nutritional status was monitored by recording body weight and plasma-free fatty acid levels throughout the study.The breeding seasons differed significantly: Finn, October to May; Merino, September to February; and Blackface, October to February. Variation in the incidence of ovulation was similar to that in the incidence of oestrus for each breed. The incidence of silent ovulation varied with the breed, being greatest in the Merino and least in the Finn. The ovulation rate varied among breeds (Finn, 2·99; Merino, 1·08 and Blackface, 1·30), and during the breeding season (e.g. Finn: November, 3·5; March, 2·6). Follicles were observed in each breed throughout the period of study.The pattern of variation in progesterone concentration was similar for each breed despite their different breeding seasons. In addition to breed differences in ovulation rate and in onset and end of the breeding season, the sensitivity to oestrogen was apparently such that, with the Finn if oestrogen secretion was high enough to stimulate ovulation it would usually also stimulate oestrus, whereas with the Merino ovulation often occurred without oestrus; this suggests that in the Merino the centres controlling ovulation are more sensitive to oestrogen than those controlling behaviour.
The effect of concentrate, barley and dried grass on the voluntary intake of different silages
Authors: McIlmoyle W. A. , Murdoch J. C. 
Published: September 2010

SUMMARYIn two experiments with steers (initial live weight 339 kg) the effect of dried grass, barley and concentrates on the intake of ‘wilted’ and unwilted grass and whole-crop barley silage was investigated.In both experiments there was no significant effect of silage type on silage dry-matter intake when given alone or with a supplement. In Experiment 1, supplementation significantly reduced (P<0·05) the intake of silage dry matter (DM) from unwilted and whole-crop barley silage. Total DM intake was significantly higher (P<0·05) for the ‘wilted’ silage diet than for either the unwilted or whole-crop barley silage diets. In Experiment 2, supplementation had no significant effect on total DM intake. Digestible energy intake was significantly higher (P < 0·05) from whole-crop barley silage supplemented with concentrate rather than barley or dried grass and was significantly lower (P<0·05) from unwilted silage diets (P<0·05) when dried grass rather than concentrate or barley was given. In the second experiment, ration digestibility and rate of passage of digesta results are reported.
The effect of milk intake on the intake of cut and grazed herbage by lambs
Authors: Penning P. D. , Gibb M. J. 
Published: September 2010

ABSTRACTFifty-three lambs were artificially reared from 1 day old. From 14 days of age they were either housed and offered cut herbage or grazed at pasture.Five milk feeding treatments were allocated to both the housed and the grazing lambs; these were a total of 50, 70, 90 and 110 kg of ewes' milk given over 12 weeks and milk substitute for 4 weeks. Three additional lambs were housed and offered milk ad libitum.Digestibilities of the dietary components, herbage and milk intakes and lamb growth rates were measured.Similar digestibility coefficients were obtained for milk and for herbage when consumed together compared with individually.Milk intake was negatively correlated with herbage intake and positively correlated with growth rate.Under conditions permitting ad libitum intake, lambs at pasture had higher intakes of herbage than lambs offered cut herbage indoors. Equations are given which enable herbage intake at a particular age to be predicted from total milk intake.
A model of nutrient utilization and body composition in beef cattle
Authors: France J. , Gill M. , Thornley J. H. M. , England P. 
Published: September 2010

ABSTRACTA simple dynamic model of metabolism in growing beef cattle is described; the scheme is based on carbon and nitrogen fluxes. There are six state variables, three relating to blood metabolite levels and three to body composition. The blood metabolite variables are acetyl-coenzyme A equivalents, glucose equivalents and amino acids, and the body composition ones are ash, lipid and protein. The fluxes in the model are based on nine biochemical transactions, six of which are catabolic and three biosynthetic. The model simulates changes in carcass composition in response to changing nutrient input and gives a measure of agreement with comparative slaughter data. It also highlights the need for more complete data on profiles of nutrient absorption in association with comparative slaughter experiments.
The voluntary hay intake by ewes during the first weeks of lactation
Authors: Bocouier F. , Thériez M. , Brelurut A. 
Published: September 2010

ABSTRACTIn eight experiments, ewes nursing one or two lambs were offered restricted amounts of concentrate in the range 285 to 605 g dry matter (DM) per day and hay ad libitum, from lambing until day 42 of lactation.Hay intake increased sharply during the first 2 weeks and reached its maximum during the 5th or the 6th week. Ewes' body weight at lambing, ewes' body-weight change, and milk production (estimated by litter growth rate) were significantly related to hay intake which depended also on breed (Romanov × Limousine ewes eating more than pure Limousine, P < 0·001) and age (mature ewes eating more than old ewes, P < 0·001) but not on number of suckled lambs.Replacement rate of concentrates for forage increased as lactation progressed (0·53 to 0·86 from first to third fortnight) and varied with hay neutral detergent fibre (NDF) concentration (0·42 or 0·89 for hays with 700 or 500 g NDF per kg DM). Daily hay DM intake decreased by 1·28 g for each gram of hay NDF content increment. The NDF effect was increasingly more important as lactation progressed.Utilization of present results in formulating diets for lactating ewes is discussed.
Production responses of New Zealand Friesian cows at pasture to exogenous recombinantly derived bovine somatotropin
Authors: Hoogendoorn C. J. , McCutcheon S. N. , Lynch G. A. , Wickham B. W. , MacGibbon A. K. H. 
Published: September 2010

ABSTRACTRecombinantly derived bovine somatotropin (bST) was administered to 25 Friesian cows by 2-weekly injections of a controlled release formulation at a dose rate equivalent to 25 mg/day. Treatment commenced 7 to 11 weeks after calving and continued for 26 weeks. A comparable group of 25 cows treated only with the slow release vehicle served as a control. During the treatment period, administration of bST increased yields of milk (controls 2358 v. bST 2598 (pooled s.e. = 39·8) kg; P < 0·01), fat (107·4 v. 119·3 (pooled s.e. = 1·9) kg; (P < 0·01) and protein (84·7 v. 93·7 (pooled s.e. = 1·2) kg; (P < 0·001). Magnitude of the treatment effect was strongly influenced by season, being greatest in spring/early summer (weeks 1 to 13 of treatment) and autumn (weeks 19 to 25) but not significant during the intervening summer dry period when herbage yield was low. Voluntary intakes, as measured by indigestible marker techniques at weeks 7 to 8 and 12 to 13 of treatment, were not influenced by bST administration. However, the net loss of body condition experienced by bST-treated cows (0·3 condition score units) was not sufficient to explain their responses in yield of milk and milk components, suggesting that some responses in voluntary intake had occurred. Administration of bST had little effect on milk composition, fatty acid composition of milk fat, live weight, reproductive performance or milk yield in the subsequent lactation.
Influence of shearing regime and grass silage quality on the performance of pregnant ewes
Authors: Black Heather J. , Chestnut D. M. B. 
Published: September 2010

ABSTRACTThe performance of housed ewes, shorn at various stages during pregnancy and offered silages ad libitum made from grass harvested at two contrasting stages of growth, was studied. The mean increase in silage dry matter (DM) intake due to shearing (0·11 kg/day; P > 0·05) was small in comparison with that resulting from offered earlier-cut silage (0·27 kg/day; P < 0·001). The mean increase in twin lamb birth weight from ewes shorn at least 6 weeks before lambing was almost 1 kg per lamb (P < 0·01) with no significant effect on ewe live-weight change. Greatest increase in lamb birth weight (1·11 kg; P < 0·01) was produced by shearing several times during pregnancy, with least response (0·23 kg; P < 0·05) from shearing once only, 4 weeks before lambing. The effect of silage quality on lamb birth weight was not significant, despite the large difference in DM intake of the two silages. This difference in intake was reflected by ewe live-weight change over pregnancy with those ewes offered early-cut silage gaining 5·57 kg while those offered late-cut silage lost 4·53 kg (P < 0·001). There was a marked fall in respiration rate and rectal temperature after each shearing and, compared with shorn ewes, unshorn ewes had a mean gestation length which was 2·04 days shorter (P < 0·01). In terms of lamb growth rates, ewe milk yields and milk composition, the performance on all treatments after turn-out to pasture was satisfactory and no significant carry-over effect of treatments applied during pregnancy were observed during the first 5 weeks of lactation.
The impact of different genetic models on the optimum design of crossbreeding experiments
Authors: Sölkner J. 
Published: September 2010

ABSTRACTA method for the iterative set-up of optimum designs for crossbreeding experiments was used to study the robustness of designs to differences in the biological interpretation of two-locus epistatic interaction. Designs could be found which are efficient for the estimation of genetic models including, alternatively, seven different types of epistatic effects. Also, the design efficiency of a large-scale beef cattle crossbreeding experiment between Angus and Hereford cattle conducted at the Clay Center, Nebraska, and reported by Koch, Dickerson, Cundiff and Gregory (1985) was investigated and found to be high (proportionately 0·88 of the optimum). It was concluded that choice of the right genetic groups (i.e. types of crossbreds) seems to be more important for a good design than the exact number of observations allocated to each group.
Growth characteristics and carcass composition of pigs with known genotypes for stress susceptibility over a weight range of 70 to 120 Kg
Authors: Aalhus J. L. , Jones S. D. M. , Robertson W. M. , Tong A. K. W. , Sather A. P. 
Published: September 2010

ABSTRACTA total of 805 Lacombe pigs of different genotype with respect to halothane sensitivity (halothane positive, nn = 205; heterozygote, Nn = 214; halothane negative, NN = 386) were slaughtered over a range in live weight (70 to 120 kg) to assess tissue growth patterns using the allometric equation (y = aXh). The nn genotype was older at slaughter than the NN genotype, but pigs from each genotype were killed over a similar weight range. The relative growth of the primal cuts was influenced by genotype, with nn pigs having a lower coefficient for the bottom shoulder (picnic) and a higher coefficient for the belly. The relative growth of bone was similar for genotypes (P > 0·05) but the relative growth of lean was lower and the relative growth of total fat and depot fat (subcutaneous and intermuscular) was higher for the nn genotype compared with the Nn and NN genotypes. On a within-tissue basis, the relative growth of the tissues in each primal was similar, except for the ham, where the relative growth of lean was higher for nn pigs compared with the two other genotypes. Small differences in tissue distribution were evident, but seldom exceeded 30 g/kg. Although nn pigs had a higher lean content and higher lean: bone ratio than Nn or NN pigs at similar live weights, their relative advantage in composition decreased with increasing live weight.
Analysis of some factors which affect the productivity of beef cows and of their calves in a marginal rainfall area of Rhodesia 2. The yield and composition of milk of suckling cows
Authors: Richardson F. D. , Oliver J. , Clarke G. P. Y. 
Published: September 2010

SUMMARYThe milk production of three groups of cows grazing on veld and receiving different amounts of concentrates during winter and the first 8 weeks of lactation was studied over four successive calving seasons. Calves were weaned at either 150 or 240 days.Cows offered most concentrates and those whose calves had been weaned early in the previous year produced more milk per lactation (P < 0·01) than other cows but weaning age did not affect yield/cow per year. Data for each treatment in each year were considered as a separate class. Regression analyses showed that milk yield increased with cow weight at calving and with calf birth weight. Changes in cow weight during early lactation, after adjusting for initial weight, were directly related to milk yield.In a concurrent experiment, three groups of heifers were confined in pens and given sufficient amounts of a complete diet to promote either gain, maintenance or loss of weight during lactation. Heifers that gained or maintained weight produced significantly (P<0·01) more milk of a higher solids-not-fat and protein content than those which lost weight. Food intake had a significant (P < 0·01) positive effect on milk yield but the effects of weight and weight change on milk yield were negative after adjusting for food consumption.
Cereal processing and food utilization by sheep 1. The effect of processing on utilization of barley by early-weaned lambs
Authors: Fraser C. , Ørskov E. R. 
Published: September 2010

SUMMARYIn Experiment 1, 24 early-weaned, male lambs were given ad libitum a diet based on either rolled or whole barley, both pelleted through a 7·4 mm die. Growth rates were 360 and 409 g/day, food conversion ratios 2·80 and 2·56 kg dry matter/kg gain, and organic-matter digestibilities 77·8 and 80·4% for the two diets respectively. In Experiment 2, 12 early-weaned, female lambs were given a diet based on either whole barley pelleted through a 7·4 mm die or unprocessed barley. When the diets were given in restricted quantities those containing unprocessed barley were slightly but significantly higher in digestibility. The feeding of unprocessed barley increased the firmness of subcutaneous fat and the contents of the rumen at slaughter, but decreased liver weight.In Experiment 3,36 early-weaned, female lambs were given ad libitum diets based on either pelleted rolled barley, pelleted whole barley or unprocessed barley. Growth rates were 260, 270 and 264 g/day; food conversion ratios were 3·20, 3·20 and 3·00 kg dry matter/kg gain organic-matter digestibilities were 80·8, 79·3 and 81·0%, rumen pH values were 5·2, 5·2 and 6·1, and liver weights 728, 788 and 673 g, for the three diets respectively. As in Experiment 2, the subcutaneous fat on the cold carcass was firmer and more acceptable to the butcher when whole barley was given.
Twinning in Israeli-Friesian dairy herds
Authors: Bar-Anan R. , Bowman J. C. 
Published: September 2010

SUMMARYThe incidence, heritability and effects on lactation performance of twinning in 185 000 calvings in Israeli-Friesian dairy herds are presented. The incidence of twinning in heifer and cow calvings (parities 2 to 6 inclusive) was 0·7 and 5·4% respectively in the large Kibbutz herds and 0·7 and 3·5% in smallholders' herds. The heritability estimate for 144 sires each with over 200 calvings of daughters of parity 2 to 6 was 0·024 ± 0·002. The range of incidence of twinning in these parities among sire progeny groups each with more than 1000 calvings was 2·8 to 7·8 %, apart from one sire, whose daughters had 12·2% twins. His progeny excelled in five characters and as an explanation it is suggested that a rare gene is segregating in the breed with a major effect on the endocrine system and associated pleiotropic effects.