bluuebunny/crossref_metadata_2025_split huggingface dataset:
A survey of the carcass characteristics of the main types of British lamb
Authors: Kempster A. J. , Cuthbertson A. 
Published: September 2010

SUMMARYCommercial lamb carcasses were surveyed in 1971/72 as part of the development programme for a national classification scheme for Great Britain. Carcasses of 421 castrated male lambs were evaluated and their left sides dissected. The sample comprised seven groups representing the main breed types in the national population. Within these groups, lambs were selected from three regions on each of three occasions corresponding with the beginning, middle and end of the normal slaughtering season for each group.The overall means (±SD) for side weight and percentage subcutaneous fat in the side were 8·3 ± 1·8 kg and 12·6 ± 3·2 respectively. When adjusted to the overall mean subcutaneous fat percentage (constant % SF), the breed-type side weight means ranged from 6·4 kg (Welsh Mountain) to 10·8 kg (British Longwool). At constant% SF, lambs slaughtered earlier in the season were lighter than those of the same breed type slaughtered later.Significant differences (P<0·05) were recorded between breed-type groups in fat distribution and lean/bone ratio. These were reflected as important differences in percentage lean at constant % SF, group means ranging from 54·5 (lambs by Suffolk rams out of Scottish Halfbred ewes) to 56·7 (lambs by British Longwool rams out of hill ewes).When lambs of the same breed type from different regions were compared at constant % SF and constant side weight, there were few important differences in carcass characteristics.The results are discussed in relation to the classification scheme which has since been introduced by the Meat and Livestock Commission.
The interpretation and analysis of subjective body condition scores
Authors: Evans D. G. 
Published: September 2010

ABSTRACTSubjective scoring data may be analysed by ranking methods, ANOVA methods or by inspection of the score distributions. These methods are discussed with particular reference to body condition scores of cows and ewes. A combination of ANOVA and ad hoc inspection was used to analyse data from trials carried out in 1976 to investigate the precision of condition scoring. On the basis of the results, recommendations are made concerning the use of condition scoring on farms and in scoring trials where the object is to monitor assessor bias and inconsistency.
Application of light control to shorten the production cycle in two breeds of sheep
Authors: Vesely J. A. 
Published: September 2010

ABSTRACTAn average of 60 Rambouillet and 60 Suffolk ewes was maintained under an intensive management system to lamb about every 7 months. Decreased daylength was used for oestrus induction in normally anoestrous periods. The experiment lasted 3·7 years, during which time six lamb crops were produced, three of them as a result of out-of-season mating. Ewes of each breed were subdivided into three experimental groups and each breed-group was maintained under one of three different light treatments before and during out-of-season mating. Imposed Treatment 1 consisted of a pre-mating period under natural daylight followed by a mating period of short daylength (8 h/day). Ewes under imposed Treatments 2 and 3 were exposed to 16 h of light during the pre-mating period and to 8 h of daylight during the mating period. This did not affect conception significantly in the Rambouillet but it did in the Suffolk. Different intensities and wavelengths of light during the long daylight period (16 h/day) were used in Treatments 2 and 3 but did not cause different responses.In Rambouillet ewes the first mating (out-of-season) gave 73% conception. It was followed by two in-season matings with 72 and 85% conceptions. The last three matings (out-of-season, in-season, out-of-season) resulted in 57, 42, and 58% conceptions. In the Suffolk ewes, the conceptions were 30, 88, 77, 3, 77, and 10% in the same order as those for Rambouillet. The average production ofRambouil-lets on the three treatments was 166 lambs per 100 ewes per year (165, 177, 157) whereas Suffolks produced 132 lambs (120, 143, 135). Control Rambouillet and Suffolk ewes maintained under natural daylight year-round produced 139 and 117 lambs.
The effects of selection for high and low body weight on the proportion and distribution of fat in mice
Authors: Allen P. , McCarthy J. C. 
Published: September 2010

ABSTRACTThe growth of adipose tissue was investigated in lines of mice selected for high and low body weight at 5 and 10 weeks of age, by dissecting and weighing individual fat depots from mice aged 5, 7·5, 10 and 15 weeks. At fixed ages most depots were heavier in the High lines and lighter in the Low lines. Depots grew at different rates and the rate of total fat deposition relative to gain in body weight was greater in High than in Low lines. At about 20g live weight High and Low lines had similar proportions of total fat; at lower weights the High lines were relatively leaner. These correlated effects of selection were more pronounced in the faster growing depots of the kidneys and gonads. In consequence, the High an d Low lines had different fat distributions at fixed ages, at fixed body weights and at fixed weights of fat.
The effect of interval between harvests and wilting on silage for milk production
Authors: Gordon F. J. 
Published: September 2010

ABSTRACTSeventy-two British Friesian cows, with a mean calving date of 21 January, were used in a 3 × 2 factorial design experiment to assess the effects of the interval between harvest and wilting on the value of grass silage for milk production. Three regrowth intervals of 5, 7 and 9 weeks were used with each material ensiled both unwilted and after wilting to a dry-matter content of approximately 450g/kg. The six silages were offered ad libitum in addition to 7·6 kg concentrates per day, from day 8 of lactation until 13 April, with a mean experimental period of 67·5 days. The mean intakes of silage dry matter were 11·2, 9·8 and 8·7 kg/day for the 5-, 7 and 9-week regrowth intervals respectively and 9·6 and 10·2kg/day for the unwilted and wilted silages respectively. Regrowth interval significantly affected milk yield with mean yields of 24·7, 24·2 and 22·5 (s.e. 047) kg/day being obtained for the 5-, 7- and 9-week intervals respectively. Wilting significantly depressed milk yield with mean yields of 24·8 and 227 (s.e. 0·39) kg/day being recorded with the unwilted and wilted materials respectively. Live weight at the end of the experiment was not significantly affected by any of the treatments but the rate of live-weight loss, calculated by linear regression over the experiment, and loss in body condition score both significantly increased with increasing regrowth interval. Wilting had no effect on live weight or body condition. Increasing the regrowth interval also significantly reduced the solids-not-fat and protein contents of the milk produced during the final week of the experiment but no other significant effects were recorded on milk composition.Blood analysis data are presented: blood urea was the only component affected by the treatments and decreased significantly as regrowth interval increased.
Individual intake variation in ewes given feedblock or trough supplements indoors or at winter grazing
Authors: Kendall P. T. , Ducker M. J. , Hemingway R. G. 
Published: September 2010

ABSTRACTIndividual dry matter intakes were measured using four groups of 16 ewes, indoors or at sparse winter grazing. In periods of varying duration (14 to 35 days) the ewe groups received 14 feedblock supplements competitively, eight trough supplements competitively or two feedblock supplements individually. In each period hay was available ad libitum. All supplements contained chromic oxide and individual supplement intakes were estimated by total faecal collection. Individual hay and total dry-matter intakes were estimated by faecal apportionment according to indigestibility of dietary components.Metabolizable energy content (0·81 × digestible energy) of the feedblocks ranged from 7·9 to 9·2 MJ/kg dry matter compared with a value of 13·0 MJ metabolizable energy/kg dry matter for concentrates. The variation in individual supplement intake was large, irrespective of type of supplement. However the mean coefficient of intake variation for 14 feedblock supplements (0·56) significantly (P < 0·05) exceeded that (0·39) for eight trough supplements at equivalent mean dry-matter intakes.Thus, ‘free-access’ feedblocks did not allow a more uniform supplementation than trough supplements. Supplement intake variation was higher outdoors and increased as total feedblock intake reduced.The variation in individual hay and total dry-matter intake was lower, and generally independent of that for the supplements. Mean coefficient of variation of 0·24 and 0·22 were obtained for hay and total dry matter, respectively, based on 22 collections with competitively fed sheep.Total daily metabolizable energy intakes of individual ewes outdoors ranged from 5 to 22 MJ per collection.
Changes in body composition relative to weight and maturity in large and small strains of Australian Merino rams 1. Muscle, bone and fat
Authors: Butterfield R. M. , Griffiths D. A. , Thompson J. M. , Zamora J. , James A. M. 
Published: September 2010

ABSTRACTMaturing patterns of carcass muscle, bone and fat were established using dissection data from 20 large mature size strain and 19 small mature size strain Merino rams. The rams were fed a pelleted ration soon after weaning and individual rams from both strains slaughtered at 6 kg increments in live weight from 18 kg to maturity at 116 and 91 kg for the large and small strains respectively.Composition of mature rams of both strains was similar for the proportion of muscle and bone but there was a slightly greater proportion of fat in the larger strain.The progress of each carcass tissue to maturity was assessed relative to progress of shorn full live weight to maturity. Maturing patterns of the three carcass tissues were not significantly different in the two strains. Muscle and bone were early maturing relative to live weight and fat late maturing.The composition of the large and small mature size strains at the same live weight and at the same proportion of maturity was predicted from the maturity patterns of the carcass tissues and the composition of the mature rams. At the same live weight the large mature size strain had a greater proportion of bone and a smaller proportion of fat than the small mature size strain. At the same proportion of mature live weight, differences between the strains in proportional composition were reduced, and the large mature size strain had slightly more fat.Some guidelines for comparison of strains of animals of different mature size are developed.
An analysis of seasonality of milk production
Authors: Goodall E. A. 
Published: September 2010

ABSTRACTThe lactation model of Wood, y = Anbe−cn was fitted, using a logarithmic transformation, to two sets of lactation data obtained from the Agricultural Research Institute of Northern Ireland. The first set was from animals calving in the autumn and the second set from animals calving in winter and early spring. A categorical variable was added to the transformed model to investigate the effect on the parameters of the animals going out to grass. The technique proved more useful with the autumn-calving herd.
Gut fill in cattle: effect of pasture quality on fasting losses
Authors: Goodchild A. V. 
Published: September 2010

ABSTRACTAn abrupt fall in live weight of grazing cattle occurs at the beginning of the growing season in the seasonally dry tropics. In an experiment with grazing crossbred bulls in central Tanzania designed to monitor changes in gut fill, 16 were slaughtered in the dry season and 14 in the early wet season. Bulls were measured and weighed before, and weighed after, a 20-h fast and then slaughtered. Gut fill was measured and empty body weight (EBW) calculated.During fasting, the ratio gut fill/EBW fell from 0·291 to 0·217 in the dry season and from 0·207 to 0·119 in the wet season. Heart girth/EBW1/3 was 0·2577 and 0·2567 m/kg1/3 in the dry and wet seasons respectively.It was concluded that live weight before or after fasting is seriously affected by season and can give biased predictions of EBW change. On the other hand, heart girth is little affected by season and can be used to monitor relative increases or decreases of EBW within animals.
Observed energy intake of weaned piglets and its effect on temperature requirements
Authors: Robertson A. M. , Clark J. J. , Bruce J. M. 
Published: September 2010

ABSTRACTEnergy intake was recorded for two batches of 12 individually-penned piglets weaned at 5 kg live weight and fed milk-based diets of 18·7 MJ metabolizable energy (ME) per kg up to 8 kg live weight and 15.4 MJ ME per kg thereafter. The piglets were kept within their thermoneutral zone throughout the experiments. Regression equations describing the relationship between energy intake and days after weaning were developed for each piglet and the means of the regression coefficients and constants were incorporated in an equation for estimating energy intakes for piglets of 5 to 15 kg live weight. The lower and upper critical temperatures were calculated for each piglet on every day of the trial. These values were extrapolated to give temperature recommendations for piglets of 5 to 15 kg live weight kept in groups of 20. The temperatures ranged from 30°C at weaning to 19°C, 23 days after weaning. This represented a reduction in temperature equivalent to 0·5°C per day.
The influence of feeding level on the protein requirement of pigs between 20 and 45 kg live weight
Authors: Campbell R. G. , Taverner M. R. , Curic D. M. 
Published: September 2010

ABSTRACTOne hundred entire male pigs growing between 20 and 45 kg live weight were used to investigate the effects on growth performance and carcass composition of eight concentrations of dietary crude protein (CP), ranging from 93 to 238 g/kg and three levels of food intake (giving mean daily digestible energy 15·6, 18·7 and 22·4 MJ).Growth rate improved with each increase in food intake and with increase in dietary CP up to 175 g/kg (10·5 g lysine per kg) at all food intakes. Food:gain ratio (g food per g growth) improved with increase in dietary CP up to 175 g/kg and with the first increase in food intake.The rate of protein deposition in the carcass (excluding viscera) increased with each increase in level of feeding, and with increases in dietary CP up to 175 g/kg. The results showed that for pigs given diets deficient in protein, the rate of protein deposition was linearly related to protein intake and independent of energy intake. For pigs given diets adequate in protein, the rate of protein deposition was related to energy intake, and independent of protein intake.The carcass fat of pigs killed at 45 kg live weight decreased on all feeding treatments with increase in dietary CP up to 175 g/kg, and was higher in pigs given the two higher levels of feeding than in those fed at the lowest level. The effect of feeding level on carcass fat content declined as the protein adequacy of the diet was reduced.
Effect of oestrous synchronization with prostaglandin F2α in Ethiopian highland zebu (Bos indicus) cows
Authors: Mukasa-Mugerwa E. , Tegegne Azage , Mattoni M. , Cecchini G. 
Published: September 2010

ABSTRACTThe length of the oestrous cycle and plasma progesterone concentration in Ethiopian Highland zebu cows were monitored after treatment with prostaglandin F2α (PGF) (25 mg Lutalyse®) 12 days after spontaneous oestrus. PGF induced luteolysis followed by a significant drop in progesterone values to proportionately 0·11, 0·04 and 0·03 of the pre-treatment values (range 6·3 to 11·4 μg/l) within 24, 48 and 72 h of PGF injection, respectively (P < 0·001). PGF treatment resulted in oestrus within 72 to 120 h and did not influence the length of the subsequent oestrous cycle (P > 0·05). Mean oestrous cycle length was 19·4 (s.d. 1·3) days. There was good correlation (r = 0·72) between the length of consecutive cycles in the same cow and the amount of progesterone the cow produced on the same day in the cycles (r = 0·69 to 0·95). As a result, a close relationship (r = 0·74) existed in the total amount of progesterone produced in consecutive cycles. These data suggest that events following PGF treatment in Ethiopian Highland zebu cows closely parallel those observed in natural cycles. Two-thirds of the spontaneous heats exhibited elevated progesterone values 2 days prior to oestrus onset.
Melatonin advances and condenses the onset of seasonal breeding in Greek dairy ewes
Authors: Kouimtzis S. A. , Belibasaki Sofia , Doney J. M. 
Published: September 2010

ABSTRACTThe effects of melatonin, administered during anoestrus, on the time of onset of oestrus and on conception rate were investigated in two trials carried out on mature ewes of three indigenous and one imported breed. The ewes lambed between December and February, their lambs were weaned in March and they were hand milked twice daily until September.In the first trial, 12 Chios and 12 Serres ewes were dosed, orally, for 60 days from 19 April with 3 mg melatonin (M) in 10 ml ethanol and water (1: 4 v/v). A similar number of Chios and Serres type ewes in the same flock were nominated as untreated controls (C). Vasectomized rams were used to detect oestrus from 1 May and detected ewes were immediately mated to entire rams of their own breed. The mean dates of first oestrus in Chios ewes were 4 July (s.e. 1·7 days) and 23 July (s.e. 5·4 days) (P < 0·01) for treated and control ewes respectively. Spread of first oestrus was 19 and 61 days, respectively (P < 0·01). Conception rate and ovulation rate were both higher in M (0·90 and 2·3, respectively) than in C (0·55 and 1·8, respectively) but the differences were not statistically significant. The corresponding results in the Serres ewes were 8 July (s.e. 1·6 days) and 31 July (s.e. 6·8 days) (P < 0·01) for date of first oestrus, 19 and 69 days (P < 0·01) for spread of first oestrus, 0·75 and 0·50 (P > 0·05) for conception rate and 1·8 and 1·2 ( P > 0·05) for ovulation rate.In the second trial, 12 Karagouniko and 12 East Friesland ewes received a single subcutaneous implant of melatonin (Regulin®) on 5 June and a further 12 ewes of each breed were untreated controls. The procedure was as given for trial 1. The mean date of first oestrus was advanced by melatonin in both Karagouniko ewes (25 July (s.e. 3·91 days) v. 11 August (s.e. 6·7 days); P < 0·05) and Friesland ewes (28 July (s.e. 3·2 days) v. 24 August (s.e. 7·3 days); P < 0·01). Spread of oestrus was reduced (43 v. 68 days in Karagouniko, P < 0·05 and 22 v. 87 days in Friesland ewes, P < 0·01). Conception rate of melatonin-treated ewes was higher (0·60 v. 0·45; P > 0·05) in both breeds. Ovulation rate was higher in melatonin-treated Karagouniko ewes (1·8 v. 1·3; P > 0·05 but, in the Friesland breed melatonin-treated ewes had a lower ovulation rate (2·8 v. 3·7; P > 0·05).In both trials, melatonin treatment significantly advanced and condensed the dates of first oestrus. Conception rate was consistently increased over all groups (P < 0·05) and there was a tendency towards a higher ovulation rate.
A field trial of Finnish Landrace rams as sires of crossbred ewes
Authors: Barker J. D. 
Published: September 2010

SUMMARYThe relative performances of crossbred ewes sired by Finnish Landrace or by non-Finnish rams were measured in trials at 18 farms which yielded a total of about 2600 ewe lambing records. The dams of the crossbred ewes were Hill breeds (40%), Upland (22%), Long-wool x Hill (20%) and other breed types (18%). The non-Finnish sires were Longwool breeds (35 %), Down and Down crosses (33 %), Upland (22%) and other breeds (10%).Finnish crossbred ewes were lighter at mating than the average of non-Finnish crossbreds by 10% at 7 months, increasing to 24% at 31 and 43 months, with an average difference of 18% for the first 4 years of life. Over the same period of 4 years Finnish crossbreds had a 27 % higher lambing percentage and 21 % higher weaning percentage than non-Finnish crossbreds.Lambs born to Finnish crossbreds were, over the 4-year period, 16% lighter for singles and 20 % lighter for multiples at birth, and 11 % for single born and 12% for multiple born at 10 weeks, than those born to non-Finnish crossbreds. But the total litter weight of lamb reared to 10 weeks per 50-kg metabolic ewe weight (at mating) was 16% more for Finnish crossbreds than for non-Finnish crossbreds.
A note on the repeatability of ultrasonic backfat measurements in pigs
Authors: Webb A. J. 
Published: September 2010

SUMMARYThe repeatability of ultrasonic backfat readings under field conditions was measured in a sample of 57 adult male (boars) and 77 young adult female (gilts) pigs. Repeatabilities of individual fat depths 6·5 cm off the mid-line at the shoulder, mid-back and loin ranged from 0·74 to 0·90. The repeatability of average backfat thickness was 0·92.
Design and evaluation of progeny testing in open-nucleus breeding systems
Authors: Mueller J. P. , James J. W. 
Published: September 2010

ABSTRACTWhen comparing progeny-testing schemes with individual performance selection, one should use equivalent selection intensities and population structures in the two systems. Adapting formulae from open-nucleus theory, the relative efficiency of progeny testing has been tested for a range of heritabilities, fertility levels, upward gene-transfer rates, mating ratios and numbers of sires selected. In sheep and beef cattle breeding, the heritability of the trait under consideration has usually to be very low to make progeny testing worth-while. High fertility increases genetic gains but does not change the relative efficiency of progeny testing. Opening the nucleus to females from the base increases genetic gains and reduces relative efficiency of progeny testing, both effects being of small magnitude. For fixed mating ratios, only a small fraction of females should be in the nucleus, but for fixed sire numbers approximately one-third of the population should be mated to proven sires. In these analyses, variances were adjusted for the effects of repeated selection and for the effects due to mixing groups with different means. This adjustment did reduce absolute genetic gains, but did not change conclusions on progeny testing efficiency and optimum design.
Partition of fat, body composition and body condition score in mature cows
Authors: Wright I. A. , Russel A. J. F. 
Published: September 2010

ABSTRACTBody condition score, assessed subjectively on the live animal, was related to the directly determined body composition of 73 mature, non-pregnant, non-lactating cows of Hereford × Friesian, Blue-Grey, Galloway, Luing and British Friesian genotypes. Relationships between condition score and chemically determined body fat were all very highly significant, and considered to be of value for predictive purposes. Differences between genotypes in the proportion of fat stored in the main depots of the body resulted in differences in the relationship between condition score and body fat. British Friesian cows had a higher proportion of their fat in the intra-abdominal depots and the lowest proportion of subcutaneous fat, resulting in their being fatter at any given condition score. Hereford × Friesian cows had the highest proportion of subcutaneous fat and were thus the least fat at any condition score. One unit change in condition score was associated with a change of 2242 (s.e. 103) MJ of body tissue energy in Hereford × Friesian, Blue-Grey, Galloway and Luing cows and 3478 (s.e. 392) MJ in British Friesian cows. These figures may be used to bring a greater degree of precision to the nutritional management of beef and dairy cows.