bluuebunny/crossref_metadata_2025_split huggingface dataset:
Algebraic models of the lactation curves for milk, fat and protein production, with estimates of seasonal variation
Authors: Wood P. D. P. 
Published: September 2010

SummaryThe lactation curves of whole milk production and of compositional quality measures may be represented by one of a family of curveswhere the coefficients a, b and c define the curve of production of a character y at week n.An analysis of protein results from over 600 000 cows, and of fat results from nearly 3000 cows gave shape coefficients (b, c) for fat percentage (-0·1316, 0·0154) and for protein percentage (-0·1223, 0·0109) showing that the lowest percentage of each occurred during weeks 8 and 11 of lactation respectively.Seasonal variations were calculated to show an expected deficiency of 0·93% fat in the spring and 0·75% protein in winter, which could be attributed to environmental influences associated with varying feeding standards.
Soaking of complete fattening rations high in poor roughage 2. The effect of moisture content and of particle size of the roughage component on the performance of male cattle
Authors: Holzer Z. , Tagari H. , Levy J. D. , Volcani R. 
Published: September 2010

SummaryTwo levels of roughage in a complete fattening diet (25 and 45%), two particle sizes of the roughage component (6 and 12 mm diameter of sieve holes), and three levels of moisture (10, 50 and 75%) were examined in a feeding trial designed in a 2 × 2 × 3 factorial arrangement.Intact male Israeli-Friesian cattle were grown from an initial weight of about 300 kg to a slaughter weight of about 520 kg. Live-weight gains were 956, 1080 and 1025 g/day, and carcass gains were 516, 584 and 563 g/day for diet moisture contents of 10, 50 and 75%, respectively. The roughage content of the diet and particle size had no significant effects. Efficiency of conversion of metabolizable energy into live weight or carcass weight was directly related to the moisture content of the diet.Weight of gut fill was directly related to the roughage content of the diet, to diet particle size and to moisture content. Animals on the moist diets had less carcass fat but more depot fat than those on the dry ration. Total volatile fatty acid concentration in the rumen liquor of animals fed on moist diets was significantly higher, and the acetate: propionate ratio was significantly lower than that of animals on the dry control diet.The improvement in performance of animals fed on moist diets may be attributed to the accumulated effect of three factors, even though the effect of each separately may not be great: (a) Increased dry-matter intake; (b) Improvement in digestibility; and (c) Increased concentration of propionic acid and consequent reduction of the acetate: propionate ratio.
A note on fibre number and diameter in muscles of large and small lines of mice compared at a fixed body weight
Authors: Hooper A. C. B. , McCarthy J. C. 
Published: September 2010

SummaryM. biceps brachii and m. tibialis anterior were studied at a fixed body weight in mice selected for high and low body weight at a fixed age. Muscle weights were approximately equal in the two lines. In general, muscles from high-line mice appeared to contain a larger number of smaller fibres than low-line mice in which there were fewer but wider fibres than in the unselected control population from which the lines were derived.
The flock-mating of progestagen-synchronized ewes 2. The influence of time of ram introduction upon mating behaviour and lambing performance
Authors: Bryant M. J. , Tomkins T. 
Published: September 2010

SUMMARYFour 2½-year-old Suffolk rams were each mated to groups of 24 Polled Dorset Horn ewes in which the oestrous cycles had been synchronized by the use of progestagen-impregnated vaginal sponges. Ram introduction occurred at either 24 or 48 hr after vaginal sponge withdrawal. Few ewes were in oestrus 24 hr after sponge withdrawal, but the majority were showing oestrus at the time of the 48-hr introduction. Mating behaviour and subsequent lambing performance of the ewes were recorded. All rams mated with the majority of their ewes. Rams introduced 48 hr after sponge withdrawal were found o t serve their ewes less frequently and over a more limited period, but they did succeed in mating with a greater proportion of their ewes during their first 30 services. There were no statistically significant differences in overall lambing rate between treatments, but the ratio of ewes lambing to ewes served on the 48-hr treatment was 92·5% compared with 72·2% for the 24-hr treatment (P < 0·05).
Selection for plasma copper concentrations within haemoglobin type in sheep
Authors: Wiener G. , Hayter Susan , Field A. C. 
Published: September 2010

SUMMARYFrom among 27 rams of haemoglobin type A the two rams with the highest plasma copper concentration and the two rams with the lowest were selected on the basis of a single determination. In the same way four rams were selected from among the 29 rams of haemoglobin type B. The average difference between the ‘high’ and the ‘low’ rams was 103 μg copper per 100 ml plasma. The rams were mated to 105 unselected females. Lambs born as a result of these matings were blood-sampled on eight occasions from 3 weeks to 29 weeks of age.The plasma copper levels of the lambs sired by the ‘high’ copper rams were higher on average than those sired by ‘low’ copper rams. The two groups diverged from 12 weeks of age onward to a maximum difference, at 29 weeks, of 18 μg copper per 100 ml plasma. There was also an initial difference of 13 μg at 3 weeks but a much smaller one at 6 and 9 weeks.There was no corresponding difference in plasma copper concentration between the offspring of haemoglobin A and haemoglobin B rams. The results are therefore consistent with the hypothesis that the association previously observed in the same flock between haemo-globin type and plasma copper level is unlikely to be due to an effect of the gene controlling haemoglobin type, but could be due effectively to a linked ‘copper gene’.Correlations between maternal plasma copper concentration 3 weeks after parturition and lamb's plasma copper level showed a marked decline as the lambs grew older, starting from around 0·6 at 3 or 6 weeks old. This suggests a maternal ‘environmental’ influence on lamb's plasma copper in addition to any genetic effects.
A note on the effect of time of uptake of colostrum on blood gamma-globulin levels, mortality and subsequent performance of housed lambs
Authors: Ducker M. J. , Fraser J. 
Published: September 2010

SUMMARYAn experiment was conducted to determine the effect of time of uptake of colostrum on blood gamma-globulin concentrations, lamb survival and subsequent growth rate. Seventy-six Greyface ewes and their lambs were housed throughout the experiment. After lambing, the lambs were either allowed to suck their dams immediately or restricted from sucking for 6 or 18 hr after birth. The gamma-globulin concentration in the lamb sera reached a peak 24 to 72 hr after the time of first suck and then gradually declined to 6 weeks. Restriction from sucking for the first 18 hr after birth did not reduce the amount of gamma-globulin absorbed compared with lambs allowed immediate access to colostrum. There was no difference between groups in lamb mortality which was low in all cases. With both single and twin lambs the best live-weight gain was achieved by lambs allowed to suck their dams from birth.
Comparison of crossbred and purebred boars for progeny growth and carcass merit
Authors: Kennedy B. W. , Conlon P. D. 
Published: September 2010

ABSTRACTProgeny tests of three Hampshire × Duroc, three Hampshire, three Duroc and five Landrace boars were performed to compare the use of crossbred and purebred boars producing pigs, intended for slaughter. Boars were double-mated to Landrace sows, and 830 sire-identified pigs from 92 double-mated litters were farrowed. Significant (P < 0·05) breed of boar effects were observed for birth weight, 21-day weight, daily gain from 56 days to slaughter and age at slaughter, but breed of boar differences for 56-day weight, backfat depth, killing-out percentage and carcass index were not significant. Progeny of the Hampshire × Duroc crossbred performed similarly to pigs sired by purebred Hampshire and Duroc boars. Progeny performance of the Hampshire × Duroc and Duroc boars was almost identical for daily gain, age at slaughter, backfat depth and carcass index. Hampshire-sired pigs grew slightly faster, but progeny of Hampshire × Duroc boars had higher killing-out percentages than either Hampshire- or Duroc-sired pigs. Purebred Landrace pigs were slower growing, had more backfat and lower carcass indexes than crossbred pigs sired by either the Hampshire × Duroc, Hampshire or Duroc boars.
Growth of bovine tissues 4. Genetic influences on patterns of bone growth and distribution in young bulls
Authors: Berg R. T. , Andersen B. B. , Liboriussen T. 
Published: September 2010

ABSTRACTBone growth patterns and distribution were compared in joints of carcasses from 277 young bulls, progeny of eight sire breeds and two dam breeds, serially slaughtered at 300 kg live weight, 12 and 15 months of age. The growth pattern for bone in a joint was estimated from the allometric equation (Y = aXb). Growth coefficients (b) were homogeneous among breed groups for bone in each joint relative to total side bone indicating that the different breeds followed similar patterns of differential bone growth. Growth impetus of limb bones was lowest in the distal parts, increasing to the proximal regions, with the fore limb showing higher growth impetus than the hind limb. Bones of the whole thoracic region showed a high growth impetus and those of the lumbar region the highest. The cervical vertebrae showed only average growth impetus, maintaining a constant proportion of total bone. Significant sire breed differences were found in the proportion of bone in each joint when adjusted to equal side bone weight but the differences were rather small and probably commercially unimportant. Differences among sire breed groups reflected differences in maturity type, with progeny of Here-ford sires representing early maturity and progeny of Chianina sires the other extreme. Functional association between muscle and bone was not reflected in a similarity of growth patterns, except for the muscles and bones of the limbs.
Plasma progesterone concentrations from before puberty to after parturition in British Friesian heifers reared on high planes of nutrition and inseminated at their first oestrus
Authors: Shotton Susan M. , Roy J. H. B. , Pope G. S. 
Published: September 2010

ABSTRACTFive autumn-born British Friesian heifers were given a high-fat milk substitute ad libitum to 12 weeks of age followed by skim milk ad libitum to 20 weeks of age and were weaned at 26 weeks of age (Treatment 1). Nine heifers were offered the high-fat milk substitute to 8 weeks of age and were weaned at 12 weeks of age (Treatment 2). First oestrus was detected by a study of cervical secretions and plasma progesterone concentrations.Heifers on Treatment 1 were significantly heavier at 12 weeks of age, but there was no difference between treatments in the mean age or weight of the heifers at first oestrus. Ten heifers conceived at their first or second oestrus (Group A) and four heifers required four to nine inseminations to establish pregnancy (Group B).Age at first oestrus was inversely related to pre-pubertal progesterone concentrations, which tended to be higher in Group B heifers. All heifers showed a small peak in progesterone concentration before first oestrus, the height being significantly greater in Group B than in group A heifers.Progesterone concentrations in cycles preceding a successful insemination tended to be lower in the 2 days before oestrus. Progesterone concentrations during pregnancy were significantly lower for the Group B heifers, and were significantly lower for all heifers during the middle 4 months of gestation than during the preceding or succeeding 2 months, with a marked dip at 140 to 160 days of gestation. Post-partum basal progesterone concentrations did not differ from prepubertal concentrations; small peaks of progesterone tended to occur before the first oestrus post partum.
A note on the effect of the level of milk consumption prior to weaning upon the silage intake and performance of weaned ‘suckled’ calves
Authors: Du Y. L. P. Le , Baker R. D. 
Published: September 2010

ABSTRACTThe silage intake and growth rate of naturally suckled calves after weaning was less than that of similar groups of artificially reared animals that had received lower quantities of milk over the period to 8 months of age. Although the silage intake of all groups was linearly related to the level of herbage intake prior to weaning, those calves consuming least herbage had the higher rate of increase in silage intake. It was concluded that silage intake can be influenced for a considerable time after weaning by the level of herbage consumption achieved during the suckling period.
The effect of protein nutrition between 5–5 and 20 kg live weight on the subsequent performance and carcass quality of pigs
Authors: Campbell R. G. , Biden R. S. 
Published: September 2010

ABSTRACTThirty male pigs weaned at 5·5 kg were used to determine the effect of diets with 164, 192 and 219 g/kg crude protein offered ad libitum to 20 kg live weight on performance and carcass characteristics during this initial phase of growth and during the period subsequent to 20 kg live weight when all pigs were fed on a diet with 181 g/kg crude protein in restrictive amounts. Between 5·5 and 20 kg live weight, pigs offered the diet with 164 g/kg crude protein grew significantly more slowly and had a significantly poorer food conversion ratio than pigs offered the two higher protein diets. Both linear fat measurement and the proportion of ether extractable material in the carcass at 20 kg live weight decreased significantly with each increase in dietary protein. Pigs offered the 164 g/kg protein diet during the initial treatment period tended to grow faster subsequent to 20 kg and during the live-weight period 20 to 45 kg had a significantly lower food conversion ratio than pigs previously offered the two higher protein diets. Over the entire production period, 5·5 to 70 kg, there were no significant differences between treatments. Likewise there were no significant differences in carcass quality parameters between treatments at 70 kg live weight.
Coefficients of inbreeding and degree of relationship for the British Friesian herd
Authors: Bowman J. C. , Butler E. A. , Tuncel E. 
Published: September 2010

ABSTRACTThe coefficients of inbreeding and the degree of relationship for British Friesian bulls used for artificial insemination by the Milk Marketing Board in sample years between 1955 and 1972 and for random samples of registered females from the same years have been calculated. The average coefficient of inbreeding was lower in bulls (0·5%) than in registered females (2·7%). The average degree of relationship was 0·7% for bulls and 2·6% for heifers.
The use of condition-scoring in dairy cows and its relationship with milk yield and live weight
Authors: Frood Moira J. , Croxton D. 
Published: September 2010

ABSTRACTFrom July 1975 to January 1977, 225 cows in three autumn-calving dairy herds were condition-scored, weighed and milk-recorded at monthly intervals. The condition score at calving was related to the ability of the animal to achieve potential milk yield. This potential milk yield was denned by the lactation curve prediction. Animals below condition score 2 at calving did not achieve their predicted milk yield, and those above condition score 2½ yielded more than their predicted milk yield. Cows in poor condition at calving gave low, late peak milk yields with a high persistency, and those in good condition at calving gave high, early peak milk yields with a lower persistency. A positive relationship of 25 ± 1·6 kg live weight per unit of condition score was established within cows in months 1 to 7 of lactation. After month 7 of lactation foetal development caused changes in live weight without changes in score.
Protein supplementation of silage-based diets for calves
Authors: Steen R. W. J. 
Published: September 2010

AbstractTwo experiments were carried out to examine the effects on the intake and performance of calves of supplementing a diet, based on high-digestibility, well-preserved grass silage, with fish meal. The effects of fish-meal supplementation were examined at each of two amounts of concentrate intake (1·05 and 2·2 kg/day) in a 2 × 2 factorial design. Fish meal was offered at a rate of 75 g/kg silage dry-matter (DM) intake. Experiments 1 and 2 involved 36 and 40 castrated male calves, respectively, which were initially 7 weeks old and had a live weight of 70 kg. The treatments were imposed for 20 weeks. The silages used in the two experiments had mean concentrations of 22-8 g nitrogen (N) per kg DM; 524 g protein N per kg total N; 59 g ammonia N per kg total N; 0·4 g butyric acid per kg DM; and 712 g digestible organic matter per kg DM. The concentrate consisted of (g/kg) 800 ground barley, 125 soya bean meal, 50 molasses and 25 mineral and vitamin supplement, respectively, and contained 29 g N per kg DM. Silage DM intakes and live-weight gains for the low and high amounts of concentrate supplementation were 1·93 and 1·46 (s.e. 0·055) kg/day and 0·84 and 1·01 (s.e. 0·013) kg/day respectively. The supplement of fish meal did not affect silage DM intake or animal performance for either concentrate intake. Proportionately, only 0·21 of the difference in live weight at the end of the treatment periods between the two amounts of concentrate intake remained at slaughter at 18 months of age. It is concluded that the optimum growth rate for autumn-born calves during their first winter can be sustained by a diet of high-digestibility grass silage supplemented with a maximum of 1·0 kg cereal-soya bean meal concentrate and that no response in performance was obtained to supplementation of this diet with fish meal.
The estimation of pig carcass composition from different measurements with special reference to classification and grading
Authors: Diestre A. , Kempster A. J. 
Published: September 2010

AbstractData for 1002 pigs slaughtered between 1979 and 1982 from the Meat and Livestock Commission's Commercial Pig Evaluation scheme were used to examine the relative precision of different measurements for predicting carcass lean concentration. The sample covered the main market weights in Britain and comprised gilts and barrows. The overall means of carcass weight and lean concentration were 66·1 (s.d. 20·00) kg and 499 (s.d. 44·2) g/kg. Predictors were examined when used in addition to carcass weight.Of the measurements taken on the intact or centre-split carcass, fat thickness measured by optical probe 65 mm from the dorsal mid line over the m. longissimus at the last rib was the most precise predictor of lean concentration (residual s.d. = 24·6 g/kg). The precision was improved significantly when a mid-line loin fat thickness measurement was added (residual s.d. = 23·7). The stability of the selected regression equations was examined by applying them to data for three other sets of carcasses (totalling 489 carcasses) sampled from commercial abattoirs between 1975 and 1983. Biases (predicted minus actual lean concentrations) ranged from +13 to −25 g/kg.Among the measurements taken on the cut surface at the last rib, fat thickness 8 cm from the dorsal mid line was the most precise predictor (residual s.d. = 22·4 g/kg). The precision was improved significantly when m. longissimus depth was added (residual s.d. = 20·3 g/kg). Prediction bias with these measurements was similar to that recorded with the intact or split-carcass measurements. In both cases, bias tended to increase with the number of independent variables in the prediction equations.
A note on the influence of breed and sire differences on iron and zinc concentration of lamb muscle
Authors: Bennett G. L. , Field R. A. 
Published: September 2010

AbstractLambs from Perendale, Merino × Perendale, Romney, Merino × Romney and Coopworth ewes, and Southdown and Suffolk sires were assigned to three groups. Groups received no treatment, nine weekly doses of 175 mg iron (Fe) per kg body weight or nine weekly doses of 175 mg zinc (Zn) per kg body weight. They were slaughtered 1 week after the last dose. Samples of m. longissimus were analysed for Fe and Zn concentration.Muscle Zn concentration was greater for Southdown-sired lambs (85·5 mg/kg dried muscle) than for Suffolk-sired lambs (77·6 mg/kg; P < 0·01). Dam genotypes and the interaction of sire breed and dam genotype were not significant for Zn concentration. Heritability of muscle Zn concentration was estimated to be 0·92 (s.e. 0·48). Muscle Fe concentration showed a significant interaction between sire breed and dam genotype (P < 0·05). Heritability of muscle Fe was estimated to be 0·21 (s.e. 0·38). No significant interactions of either sire breed or dam breed × treatment were found.
Concentrations of LH and oestradiol-17β in plasma of the dairy cow during the post-partum acyclic period
Authors: Watson Elaine D. 
Published: September 2010

AbstractThe concentrations of LH and oestradiol-17β were measured in samples of jugular venous plasma collected frequently during an 8-h period from six acyclic cows between 21 and 27 days post partum. Fluctuations in oestradiol-17β concentrations were detected. Although the mean concentrations of oestradiol were similar whether ovulation occurred within 1 week of sampling or not, the amplitude of the fluctuations in oestradiol concentrations was greater in the three cows which ovulated within 1 week of the period of sampling. Increases in the concentration of LH were frequently followed by increases in the concentrations of oestradiol.
Metabolic rate responses to cold and to exogenous noradrenaline in newborn Scottish Blackface lambs genetically selected for high or low resistance to cold
Authors: Slee J. , Simpson S. P. , Woolliams J. A. 
Published: September 2010

AbstractNewborn Scottish Blackface lambs from lines previously selected for high (H) or low (L) resistance to body cooling were tested for their metabolic response (O2 consumption) to cold exposure in a water bath or to subcutaneous injections of exogenous noradrenaline as a measure of non-shivering thermogenesis (NST). Six rams from the H line and six rams from the L line were used to produce lambs such that each sire had both cold-tested (no. = 48) and noradrenaline-tested (no. = 86) progeny.The mean elevations in metabolic rate produced by cold exposure and by noradrenaline were, respectively, 3·4 times and 2·4 times resting (thermoneutral) metabolic rate. H lambs showed significantly greater cold resistance and metabolic response to cold than L lambs. H lambs showed greater NST than L lambs but the difference was not significant. There were significant sire effects on NST, indicating genetic variation. There was a significant correlation between the metabolic responses to cold and those o t noradrenaline among the sire progeny groups. NST capability appears to be a phenotypic component of neonatal cold resistance which would respond to genetic selection, but this genetic variation is not a major component of that determining cold resistance.