bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of loci associated with quantitative effects in dairy cattle improvement
Authors: Soller M. 
Published: September 2010

ABSTRACTThe use in dairy cattle improvement of loci associated with quantitative effects that might be found by genetic analysis is discussed. These methods can make a significant contribution only if they result in the identification of quantitative loci whose inheritance can be followed in a simple Mendelian manner. Another possibility, the identification of genetic components of production having a higher heritability than overall production, would make only a minor contribution to increased genetic progress. Selection of young males, according to the estimated breeding value associated by linkage with particular marker alleles in their sire, will not make a detectable contribution to genetic improvement.
The effect of urea on digestion and voluntary intake by sheep of diets supplemented with fat
Authors: Ørskov E. R. , Hine R. S. , Grubb D. A. 
Published: September 2010

ABSTRACTTwo experiments were conducted to determine whether the depression in fibre digestion caused by inclusion of fat in diets could be alleviated by addition of urea and whether the physical incorporation of fat in itself caused a reduction in rate of fibre digestion.Early-weaned lambs were given dried grass containing either 65 or 130 g/kg of tallow with or without 15 g/kg of urea. Fat inclusion caused a linear depression in intake and fibre digestibility. The depression in intake was partly alleviated by urea inclusion, but urea did not affect fibre digestibility.The physical incorporation of fat into dried grass did not in itself appear to depress rate of digestion. It is suggested that if coating of feed particles is important then this would be due to non-esterified fatty acids in the rumen and not to triglycerides.
Possible association between the breeding value of dairy bulls and milk yield of their mates
Authors: Taylor C. S. , Monteiro L. S. , Murray J. , Osmond T. J. 
Published: September 2010

ABSTRACTBritish Friesian and Jersey cows were mated either to high contemporary comparison (CC) bulls for their first pregnancy and to low bulls for their second pregnancy, or vice versa. Sixteen proven bulls were used, four ‘high’ and four ‘low’ in each breed. Least squares analysis of data on 175 lactations gave estimates of each bull's effect on his mates' milk yield in the ensuing lactation, but there were no significant differences between bulls for this ‘mate effect’. The high bulls tended to depress their mates' milk yield in the subsequent lactation and the low bulls tended to increase it. Weighted regressions of the ‘mate effect’ on breeding value had negative slopes for both breeds and for first and second lactations, separately or combined. The high CC bulls appeared to depress their mates' milk yield by at least 10% of the amount by which their daughters' yield was expected to increase.
Age, weight or total feed intake as bases for the performance testing of growing pigs
Authors: Lodge G. A. , Lister D. , Wood J. D. , Wolynetz M. S. 
Published: September 2010

ABSTRACTIn an experiment which showed that the results of a genotype comparison are influenced by the design of the test, 16 castrated male and 16 female pigs of each of Large White (LW) and Gloucester Old Spot (GOS) breeds were allocated equally among four treat- ments: WW—rationed by weight and slaughtered by weight; A A—rationed by age and slaughtered by age; AW—rationed by age and slaughtered by weight; and WF—rationed by weight and slaughtered after a common total feed intake. The experiment was designed so that performance of LW would be similar on all treatments, and the degree to which the GOS differed from the LW on each of these treatments was then evaluated. All pigs started on the experiment at 12 weeks of age, at which time mean weight of the LW was 14% greater than the mean for the GOS. The only between- breed difference that was statistically significant (P<0·05) on all treatments was weight of lean. Average daily gain and efficiency of feed conversion were significantly different between breeds only on the WW treatment. Weight of fat was significantly different on WW and AW but not on AA or WF.
Pre-pubertal mammogenesis in the sheep 1. The effects of level of nutrition on growth and mammary development in female lambs
Authors: Johnsson I. D. , Hart I. C. 
Published: September 2010

AbstractFemale lambs were given a high energy and high protein diet in varying amounts to achieve either high (H; 220 g/day) or low (L; 110 g/day) rates of gain during two consecutive periods between 4 and 20 and 20 and 36 weeks of age. The effects on body growth and mammary gland development were compared by slaughtering an initial group of four lambs at 4 weeks of age (mean live weight 11 kg), eight L lambs (24 kg) and eight H lambs (33 kg) at 20 weeks of age, and eight LL lambs (36 kg), eight LH lambs (49 kg) and eight HL lambs (48 kg) at about 36 weeks of age.At slaughter, a single mammary fat pad from each lamb was trimmed and weighed, and the deoxyribonucleic acid (DNA) content of the portion containing parenchyma determined. The mean weight (g) and DNA content (mg) were: 4-week-old lambs, 8·6 g, 1·5 mg; L, 14·7 g, 32·3 mg; H, 30·0 g, 25·9 mg; LL, 46·0 g, 61·2 mg; LH, 86·7 g, 91·0 mg; HL, 70·3 g, 73·0 mg respectively. Relative growth coefficients for mammary parenchyma, estimated from the increase in DNA relative to that for live weight, were 3·7 and 2·4 for L and H lambs respectively, between 4 and 20 weeks, and 1·6, 1·4 and 2·6 for LL, LH and HL lambs respectively, between 20 and 36 weeks of age.These results are consistent with the hypothesis that a high plane of nutrition can decrease the rate of allometric growth of mammary parenchyma before puberty. However, the cessation of this growth phase was not related to the attainment of puberty, or of a specific live weight or age, but may be related to the availability of mammary fat pad tissue limiting further parenchymal development after 20 weeks of age.
Pre-pubertal mammogenesis in the sheep 2. The effects of level of nutrition on the plasma concentrations of growth hormone, insulin and prolactin at various ages in female lambs and their relationship with mammary development
Authors: Johnsson I. D. , Hart I. C. , Simmonds A. D. , Morant S. V. 
Published: September 2010

AbstractFemale crossbred lambs were given a high energy and high protein diet in varying amounts to achieve either high (H; 220 g/day) or low (L; HOg/day) rates of live-weight gain during two consecutive periods between 4 and 20 and 20 and 36 weeks of age. Blood samples were collected via jugular catheters at either 1-h or 2-h intervals over a 28-h period from five lambs on each rearing treatment at 10, 14, 18, 26 and 34 weeks of age for the measurement of prolactin, growth hormone (GH) and insulin. In addition, samples were collected within 2 weeks of slaughter from all eight lambs on each treatment that were slaughtered at either 20 weeks (L and H treatments) or 36 weeks of age (LL, LH and HL treatments) for the assessment of mammary development.The timing of once-daily feeding influenced the plasma profiles of all three hormones measured, but became less obvious with increasing age. Both mean plasma GH, and the influence of level of nutrition on the mean, declined with increasing age. Mean plasma insulin increased with age but did not differ between rearing treatments until 26 weeks, despite large differences in food intake. Mean plasma prolactin in H lambs increased significantly between 10 and 18 weeks, but a similar response did not occur in L lambs. The greater mammary development of L lambs was associated with increased plasma concentrations of GH and reduced concentrations of prolactin. However, the large variation in total mammary parenchymal deoxyribonucleic acid between individuals within each rearing treatment at 20 or 36 weeks of age was not consistently explained by the variation in any of the hormones measured.
The effect of environmental temperature during pregnancy on thermoregulation in the newborn lamb
Authors: Stott A. W. , Slee J. 
Published: September 2010

AbstractTwenty-four pregnant Scottish Blackface ewes were divided into three temperature-treatment groups 14 days before expected lambing: closely shorn and kept at 6°C (cold treatment, CD); in full fleece at 26°C (warm treatment, WM); and in full fleece at 6°C (controls, CL). Food allocation and intakes were similar for each group. Their lambs were tested for cold-induced summit metabolic rate capability (SMR) on the day of birth at a mean age of 12 h using water immersion to provide cooling. On the following day, the calorigenic response to subcutaneous injections of noradrenaline (NA) was measured to assess non-shivering thermogenesis capability. The ewes were blood-sampled during pregnancy and the lambs before and after the SMR test.In the ewes, blood glucose and free fatty acid levels were higher during cold treatment, but not significantly so. Blood glucose was lower in lambs from CD ewes (CD lambs) before SMR tests; other differences were not significant.During the cold test, SMR was highest in CD lambs, but not significantly so. Rectal temperature declined least during test in the CD lambs (P < 0·05).The peak metabolic response (PMR) following NA injection was about 1·5 times greater in CD lambs than in the CL and WM lambs (P < 0·05). The mean elevation of PMR over thermoneutral metabolic rate was respectively: 2·8, 1·8 and 1·7 times in the CD, CL and WM lambs (P < 0·05), and this elevation was sustained for longer in the CD lambs (P < 0·01). Thus, the total metabolic response to NA was markedly greater in CD lambs.It was concluded that cold exposure during late pregnancy favoured the deposition of (or checked the normal decline in) foetal brown adipose tissue, so raising the neonatal capacity for non-shivering thermogenesis.
Interrelationships between growth, gonadotrophin secretion and sexual maturation in gilts reared in different litter sizes
Authors: Deligeorgis S. G. , English P. R. , Lodge G. A. , Foxcroft G. R. 
Published: September 2010

AbstractOne gilt from each of 24 littermate trios was assigned at birth to one of three treatments which were to adjust litter size to six, nine or 12 piglets. Plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured before and after stimulation with 1 ng gonadotrophin-releasing hormone (GnRH) per kg body weight at 55 and 140 days of age. At 150 days, oestrogen was administered and ovarian and uterine responses were measured at slaughter on day 160.Litter size significantly modified pre-weaning growth rate (P < 0·01) but did not influence gonadotrophin secretion or sexual maturity at slaughter. The family of origin significantly influenced ovarian and uterine development (P < 0·05) and the LH and FSH responses to GnRH at 55 days (P < 0·05). Family size (P < 0·01) and sex ratio of the litter at birth (P < 0·05) also influenced the ovarian response to oestrogen treatment. Significant sire effects on ovarian and uterine development were established (P < 0·05); for the progeny of individual boars significant differences in the response to oestrogen were associated with significant differences in growth rate (P < 0·001).Variations in family birth and litter weaning weights were negatively correlated with ovarian and uterine development (P < 0·05), whereas all measures of growth from weaning to slaughter were significantly and positively correlated with sexual maturity at slaughter (P < 0·05).Basal FSH and the responses of both LH and FSH to GnRH at 55 days were correlated with growth rate at day 55 (P < 0·05). Basal LH and FSH at day 140 were correlated with ovarian and uterine development at day 160 (P < 0·05).
Sources of variation in yields and concentrations of milk solids in dairy cows
Authors: Rook A. J. , Fisher W. J. , Sutton J. D. 
Published: September 2010

AbstractEighteen multiparous Holstein-Friesian cows were offered grass silage ad libitum and 3,6 or 9 kg dry matter per day of concentrates. Triplicate milk samples were taken at each of two daily milkings over a 28-day period and analysed for fat protein and lactose concentration. Milk yield and fat concentration were more variable than protein and lactose concentrations both between animals and between days. Sampling variation was small for all component concentrations. The main source of variation for all traits was time of milking (morning or afternoon) followed by variation between cows and by day-to-day variation. There was little linear trend with time in the data due to cows being close to peak yield. There was no evidence of cyclical variation over time for any trait. Mean weekly or monthly yields and concentrations were better predicted using samples from four rather than from two consecutive milkings but there was no further advantage from using six samples.
The performance of crossbred dairy calves given different levels of whole milk and weaned at different ages
Authors: Khalili H. , Crosse S. , Varvikko T. 
Published: September 2010

AbstractForty-five Friesian × zebu crossbred calves (4 days old) were used to evaluate the effect of feeding different levels of whole milk and weaning at different ages. A total of 252 I whole milk offered over 12 weeks was compared with a feeding level of 134 I milk offered over 8 weeks. Water given ad libitum was also compared with allowing access to water once daily. The calves were penned and fed individually. The average daily gain of the calves weaned at 12 weeks was 464 g compared with 378 g for the calves weaned at 8 weeks of age and allowed access to water once daily and 422 g for the calves weaned at 8 weeks and given water a d libitum. Feeding extra milk and weaning at 12 weeks decreased the intake of concentrates and significantly (P < 0·05) increased live-weight gain. Allowing ad libitum access to water was associated with an increase in concentrate intake but this was not reflected in a significant increase in animal performance.
Lactation curves for several US sheep breeds
Authors: Sakul H. , Boylan W. J. 
Published: September 2010

AbstractLactation curves for several dairy traits in sheep were studied. Data were collected from seven pure breeds, three synthetic breeds and twelve single breed crosses in a 5-year milking trial. Wood's lactation model (yn = anbe-cn) was used to describe the lactation curves. Actual and fitted lactation curves had the same shape within each trait except for proportion of lactose. Correlations between actual and fitted lactation curves ranged from 0·92 to 0·99 for all traits except lactose (0·24). There was no apparent explanation for the low correlation for lactose content. It was concluded that the algebraic formula can be used to obtain estimates of parameters for sheep lactation curves. However, some caution should be exercised in extending results to proportion of lactose in the milk.Crossbred groups had higher total milk production than pure and synthetic breeds. Lactation curves for crossbred ewes, grouped by breed of sire, had a similar pattern. Finnsheep and Rambouillet-sired crossbred ewes produced proportionately 0·23 more milk than ewes sired by Dorset and Lincoln rams. Breed differences in total milk production were observed among the pure breeds. The Suffolk breed was superior in milk production. All breeds, except the Romanov, followed a similar pattern for lactation curves. The Romanov breed produced milk at a relatively low but consistent level throughout the lactation trial.
Plasma metabolite and hormone concentrations as predictors of dairy merit in young Friesian bulls: effect of metabolic challenges and fasting
Authors: Mackenzie D. D. S. , Wilson G. F. , McCutcheon S. N. , Peterson S. W. 
Published: September 2010

AbstractResponses to metabolic challenges were measured in 8-month-old Friesian bull calves with a view to identifying possible predictors of genetic merit for milk fat production. Seven ‘high’ breeding index bulls (mean breeding index for milk fat = 128·9 (s.d. 4·8) percentage units) were compared with six ‘low’ breeding index bulls (mean 107·3 (s.d. 2·4) percentage units). Bulls were from two selection lines and breeding indices calculated as the average of parental breeding index values.Challenges involved intravenous injection of the following (dose rates per kg body weight): adrenalin (1 μg); glucose (0·17 g); glucagon (0·175 μg); insulin (0·01 mg); and arginine (40 mg). Blood samples were withdrawn prior to and after each challenge (two challenges daily). Bulls were then fasted for 3 days before being refed.Relative to the low breeding index bulls, those in the high breeding index group exhibited: (a) greater pancreatic sensitivity to circulating glucose as indicated by increased insulin concentrations following the glucose challenge; (b) more rapid clearance of glucose from plasma following the insulin challenge; (c) reduced sensitivity to the glycogenolytic/gluconeogenic effects of glucagon as indicated by lower blood glucose concentrations following intravenous injection of this hormone; (d) elevated plasma insulin and growth hormone concentrations during the fasting period; (e) elevated plasma concentrations of insulin, glucose and urea during refeeding; (f) no difference in responses to intravenous arginine or adrenalin, or in circulating concentrations of Insulin-like Growth Factor-1 or alkaline phosphatase. Results are consistent with previous observations that metabolic differences between cattle in the Massey University high and low breeding index lines are most evident in the metabolism of glucose and insulin. Metabolic challenges offer a potentially useful means of predicting genetic merit for milk fat production but the conditions under which repeatable differences between the lines can best be demonstrated are yet to be determined.
The use of fish meal and monensin as supplements to grass silage and their effect on body composition changes in steers from 5 months of age to slaughter
Authors: Gibb M. J. , Baker R. D. 
Published: September 2010

AbstractFish meal and monensin, as supplements to grass silage, were offered either separately or together to Friesian steers from 5 to 9 months of age (period 1). At 9 months, six steers from each of the supplemented treatments were slaughtered to determine body composition. Of the remaining steers, from 9 months of age to slaughter at 490 kg live weight (LW) (period 2), six continued on each of the same treatments, whilst six received silage unsupplemented. A further group of six steers which had received fish meal and monensin during period 1, received monensin only as a supplement to their silage.During period 1 fish-meal supplementation increased LW, empty body and carcass weight gains, and tissues gains, while monensin had no apparent effect. During period 2, continued supplementation with both fish meal and monensin significantly increased LW, empty body and carcass gains compared with the continuously unsupplemented steers, whilst fish meal and monensin separately produced intermediate increased gains. All three supplement regimes significantly reduced the time taken to reach slaughter.The only significant effect on body composition was that steers receiving fish meal and monensin had a higher crude protein concentration in the empty body than those receiving only fish meal as a supplement. They also had the highest crude protein concentration in the carcass, although this was not significant. Steers which had their supplements withdrawn after 9 months of age generally maintained gains intermediate between those continuing to receive supplements and those steers unsupplemented throughout. Only those not continuing to receive fish meal and monensin together appeared to perform appreciably worse. Nevertheless, although time taken to reach slaughter from 4 months of age varied by as much as 96 days, there were no other significant differences in body or carcass composition, hi terms of cost effectiveness, use of monensin showed distinct advantages over fish meal.
Effect of feeding frequency on diurnal variation in plasma and urinary purine derivatives in steers
Authors: Chen X. B. , Grubic G. , Ørskov E. R. , Osuji P. 
Published: September 2010

AbstractThe diurnal changes in plasma concentration and urinary excretion of purine derivatives (PD) were examined in four steers given their food in either one or two meals daily in two 18-day periods. In period 1, two steers were fed once daily (at 08.00 h) and the other two twice daily (at 08.00 and 16.00 h). In period 2, the treatments were switched. In the last 4 days of each period, plasma samples were taken from 08.00 to 24.00 h at 2 to 3 h intervals, and daily urine was collected in several 4 to 8h periods. With once daily feeding, allantoin concentration in plasma varied from 090 to 1·07 of the daily mean and with twice daily feeding, from 0·97 to 1·05 of mean. The coefficient of variation (CV) for total variation was 0·14. In urine, the concentration and hourly excretion of PD varied with sampling times (P < 0·05) but the ratio of PD to creatinine was relatively constant even for once-daily feeding (CV, 0·02 for measurements at different times). The CV for total variation in the ratio was 0·19. The results suggest that diurnal variation in plasma allantoin concentration and in the ratio of allantoin (or total PD) to creatinine are relatively small even for once daily feeding. It thus seems that these measurements in spot samples may be suitable for use as a simple index of microbial protein supply if they are correlated with the daily PD excretion. The results also indicate that measurements in samples of plasma and urine taken between 15.00 and 20.00 h tended to give a better representation of the daily mean.
Calcium hydroxide treatment of malt distillers' grains 1. Effects on chemical composition and digestibility measuredin vitroandin sacco
Authors: Offer J. E. , Offer N. W. 
Published: September 2010

AbstractExperiment 1 investigated the effects of calcium hydroxide (Ca(OH)2)treatment (80 g/kg malt distillers' grains (MDG) dry matter (DM) at ambient temperature (L) and at 60°C (LH). Organic matter digestibilitiesin vitro(1V0MD) were 0·30, 0·50 and 0·56 (s.e. 0·023) for untreated (C), L and LH respectively. The increase in IVOMD was less with MDG that had previously been ether-extracted (corresponding values 0·47, 0·53 and 0·54). The proportion of lipid in soap form was 0·03, 0·35 and 0·46 (s.e. 0·03) for C, L and LH respectively. Experiment 2 investigated the effects of treatment time, temperature and Ca(OH)2concentration on composition, IVOMD and organic matter digestibility in sacco (ISOMD). Response was most dependent on Ca(OH)2concentration. Mean values for 0, 40, 80 and 120 g Ca(OH)2per kg DM were for neutral-detergent fibre (NDF) (g/kg DM) 704, 586, 422 and 382; for water-soluble carbohydrate (g/kg DM) 2, 4,40 and 44; for ISOMD 0 h (without incubation) 0·25, 0·25, 0·51 and 0·57; for ISOMD 24 h (24-h rumen incubation) 0·63, 0·66, 0·84 and 0·86 and for IVOMD 0·51, 0·55, 0·65 and 0·65. Increasing treatment temperature from 20 to 80°C increased mean ISOMD 0 h from 0·31 to 0·49 but had less effect on ISOMD 24 h (0·74 and 0·79 respectively). Experiment 3 investigated the effects of treatment with 80 g Ca(OH)2per kg DM at 60°C for 16 h on rumen degradation in sacco. Instantaneous losses (a values%) for OM and NDF were increased by treatment from 14·6 to 45·5 and from 8·6 to 18·6 respectively. Treatment increased effective degradability (at 0·06 per h rumen outflow rate) from 0·43 to 0·66 for OM and from 0·40 to 0·46 for NDF. Total potentially digestible OM (a + b) increased from 0·65 to 0·91 for OM and from 0·58 to 0·84 for NDF. Ca(OH)2treatment enhances the nutritional value of MDG. Its mode of action involves reduction of the toxicity to rumen micro-organisms of unsaturated lipid by soap formation and the effect of alkali on the composition of the carbohydrate fraction.