bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of food intake during lactation and post weaning on the reproductive performance and hormone and metabolite concentrations of primiparous sows
Authors: Carroll C. M. , Lynch P. B. , Boland M. P. , Spicer L. J. , Austin F. H. , Leonard N. , Enright W. J. , Roche J. F. 
Published: September 2010

AbstractThe objective of this study was to investigate the effect of low food intake on post-weaning fertility and hormone concentrations in primiparous sows. One hundred and forty primiparous sows (Landrace × Large White) were randomly assigned to one of four treatment groups: (A) restricted to 3 kg food per day during lactation and 2 kg food per day post weaning (no. = 36); (B) restricted to 3 kg food per day during lactation andad libitumfeeding post weaning (no. = 33); (C)ad libitumfeeding throughout with a mean voluntary food intake of 3·7 kg/day during lactation (no. = 36); and (D)ad libitumfeeding throughout with a mean voluntary food intake of 4·9 kg/ day during lactation (no. = 35). Litters were standardized at eight to 10 pigs at 2 days post partum and were weaned at 27·2 (s.e. 0·5) days post partum. After weaning, sows were observed twice daily for signs of oestrus and were mated on the day(s) of standing oestrus. Six sows from each group were fitted with indwelling jugular cannulae 2 days before weaning. Blood samples were collected 1 day before weaning (W−l), 1 day after weaning (W+l) and 4 days after weaning (W+4), and these sows were slaughtered on W+4. Ovaries were recovered, follicles and corpora lutea were counted, and folUcular fluid collected. Sows given food at a restricted level (groups A and B) lost more backfat during lactation than sows given foodad libitum(groups C and D) (P < 0·01). Piglet weaning weights, weaning to conception intervals and the proportion of sows ovulating by W+4 were not significantly different among groups. In sows that did not ovulate, numbers of large follicles were not significantly different among groups but the low food intake (groups A, B and C) sows had more medium-sized follicles than high food intake (group D) sows (P < 0·01). FolUcular fluid concentrations of oestradiol, progesterone and insulin-like growth factor-1 (IGF-1) did not differ among groups (P > 0·05). Plasma non-esterified fatty acids concentrations were greater in groups C and D than in groups A and B on W−l, W+l and W+4. Serum insulin and plasma glucose concentrations were lower in groups C and D than in groups A and B on W−l and W+l, but were similar among groups on W+4. Serum growth hormone concentrations were lower in group D than group A and B on W−l and W+l but not W+4. Concentrations of IGF-1 in serum were greater in groups C and D than groups A and B on W−l and W+l but not W+4. It is concluded that low food intakes during lactation and post weaning affected body condition, serum hormones and metabolites and ovarian function of primiparous sows without dramatically affecting ovarian hormones or reproductive performance.
Selection of Merino sheep for resistance to Haemonchus contortus: genetic variation
Authors: Woolaston R. R. , Piper L. R. 
Published: September 2010

AbstractAn animal model was used to estimate heritabilities of faecal egg count (FEC) and packed cell volume decline (PCVD) in lines of Merinos selected for divergent levels of resistance to Haemonchus contortus. The estimated heritability of FEC was 0·23 (s.e. 0·03) and of PCVD was 0·21 (s.e. 0·03). A cube root transformation was found to be effective in normalizing FEC data and reducing the range of within selection line-birth year variances from 118-fold to 10-fold. Transforming FEC data increased the heritability estimate to 0·29 (s.e. 0·03) and reduced selection bias due to heterogeneity of variance, but the further step of pre-adjusting the transformed data to a common variance had only a trivial effect. Heritability estimates for FEC in years with high means and variances were similar, as were estimates for transformed FEC. The estimated genetic correlations between measurements in years with high and low means and variabilities were 0·77 to 0·91.PCVD and pre-adjusted transformed FEC had a phenotypic correlation of 0·48. Estimates for the genetic correlation ranged from 0·76 in the decreased resistance line to 1·00 in the increased resistance line and 0·87 with pooled data. Other effects on resistance included birth type and dam age, with twins and progeny of maiden dams being more resistant than their cohorts. Sex effects were unimportant for FEC but males had higher PCVD than females in most, but not all, years. Younger animals had higher FEC and PCVD than older animals. Maternal genetic effects were found to be unimportant, as were the effects of low levels of inbreeding.
Breeding season and ovulation rate in ewes treated with long days in spring followed by a melatonin implant and exposure to a ram
Authors: Sweeney T. , O'Callaghan D. 
Published: September 2010

AbstractWhile the onset of the breeding season in ewes can be advanced up to 7 weeks following exposure to long days (44 days) before lambing, a melatonin implant from lambing and exposure to a ram from the summer solstice, this advance is reduced by the absence of a ram. The aim of this experiment was to determine if earlier exposure to the ram and/or exposure to more long days before lambing would further advance the onset of the breeding season. A further aim was to compare the ovulation rate and duration of the breeding season between ewes with a normal and advanced onset of the breeding season due to this treatment regime. Pregnant ewes lambing in mid March were allocated to treatments as follows: (1) controls, maintained on natural photoperiod; (2) 44 LD + mel, exposed to 44 long days (18L: 6D; LD) before lambing followed by a 700-mg melatonin implant after lambing; (3) 90 LD + mel, as in treatment 2, but exposed to 90 LD before lambing; (4) 90 LD + mel + ram, as in treatment 3, including continuous exposure to a vasectomized ram from 10 April. Reproductive state was assessed from serum progesterone concentrations in blood collected at 3- to 4-day intervals from 10 April and ovulation rate was determined during the luteal phase of the first five oestrous cycles in control ewes and ewes exposed to 90 LD + mel + ram. Ewes exposed to 90 LD + mel + ram commenced the breeding season 10 weeks earlier (median date 25 July, range 28 days;P< 0·001) than controls (median date 8 October, range 68 days). Overall, the onset of the breeding season was not advanced in ewes given 44 or 90 LD + mel in the absence of a ram, but a biphasic response was evident, with 40 to 50% of ewes beginning the breeding season at the same time as ewes on 90 LD + mel + ram. Ovulation rate was similar between control ewes and ewes exposed to 90 LD + mel + ram (P > 0·05). The duration of the breeding season was longer in ewes exposed to 90 LD + mel + ram (210 (s.e. 15) days;P< 0·002) than in control ewes (158 (s.e. 10) days), with no difference in date of the end of the breeding season (P > 0·05). Exposure of ewes to 90 LD before lambing in March, followed by a melatonin implant and exposure to the ram from 10 April advanced the onset and extended the duration of the breeding season without an overall effect on ovulation rate. The ram is an important component of this signal sequence.
The effect of GnRH analogue (buserelin) treatment on day 12 post mating on ovarian structure and plasma progesterone and oestradiol concentration in ewes
Authors: Beck N. F. G. , Jones M. , Davies B. , Mann G. E. , Peters A. R. 
Published: September 2010

AbstractAn investigation was conducted into the effect of buserelin treatment on day 12 post mating on ovarian function and plasma progesterone and oestradiol-17 ji concentration in ewes. Changes in ovarian structures were determined, at laparoscopy or after slaughter, 48 h after treatment in 38 control and 41 ewes given an injection of 4 jig buserelin on day 12 post mating (day 0 = day of oestrus). Ovulation rate was higher in buserelin treated (2·76) than in control (1·87) ewes (P < 0·05). Moreover, 41 of the 113 corpora lutea observed in the buserelin group were the result of ovulations that had occurred within 48 h post treatment, compared with two of 71 in the controls (P < 0·05). Blood samples were collected from 10 ewes in each treatment group for hormone analysis. Mean progesterone concentrations tended to be higher, in samples collected from 2 to 6h post treatment, in the buserelin group (4·31 (s.e. 1·32) p.g/1) compared with the control group (3·71 (s.e. 1·44) fig/l. Furthermore, overall mean oestradiol concentrations were lower, during days 13, 14 and 15 post mating, in buserelin treated (0·72 (s.e. 0·26) ngfl) than in control (0·94 (s.e. 0·50) ng/l) ewes (P < 0·05). The results of this study indicate that buserelin treatment on day 12 post mating changes ovarian function.
Adaptation of whole animal energy metabolism to undernutrition in ewes: influence of time and posture
Authors: Ortigues I. , Vermorel M. 
Published: September 2010

AbstractThe effects of undernutrition and of the duration of undernutrition on changes in whole animal energy metabolism and on spontaneous physical activity were studied in adult, non-lactating, non-pregnant ewes. Animals were first given food at 338 kj metabolizable energy (ME) per day per kg live weight 0·75 (LW0·75), (M). Intake was then reduced by half (0·5M) during 7 weeks. Diet apparent digestibility decreased slightly with undernutrition. Rate of LW loss remained constant throughout the whole 0·5M period. Heat production (HP) declined by proportionately 0·18 within the 1st week at 0·5M and by another 0·05 in the following weeks. These latter changes were directly related to LW loss, since HP scaled to metabolic LW remained unchanged over the whole 0·5M period. Time spent standing decreased with undernutrition from proportionately 0·42 at M to 0·33 at 0·5M as a result of a reduction in the average duration of individual standing periods at all hours of the day except in a few hours preceeding feeding times. Energy cost of standing could not be dissociated from the energy cost of eating; these overall costs were not clearly modified by undernutrition but varied with time post prandially. Standing cost alone was estimated at 10 J/min per kg LW. Efficiency of ME utilization for maintenance (km) was calculated at 0·71, and ME requirements for maintenance (MEm) at 338 kj/day per kg LW0'75. No adaptation was noted with the duration of undernutrition. Accounting for the behavioural adaptation tended to increase km to 0·74 but MEm remained unchanged, suggesting that the behavioural changes observed with undernutrition were not sufficient to significantly modify whole animal energy metabolism.
The effect of housing and food restriction during winter on growth of male red deer calves
Authors: Webster J. R. , Corson I. D. , Suttie J. M. 
Published: September 2010

AbstractLow winter growth is a characteristic of male red deer and is caused, in part by a combination of reduced appetite and higher energy expenditure due to cold weather. This study aimed to determine whether housing during winter would reduce energy expenditure and increase the growth rate of male red deer calves. An additional aim was to investigate whether food restriction in winter would be compensated for by increased spring growth. In each of two consecutive years, 80 calves were randomly allocated to eight groups (no. = 10) comprising two replicates of four treatments during winter. Groups were housed inside (I) or outside (O) and given food either ad libitum (AL) or restricted (R) to maintain live weight. Winter treatments (southern hemisphere) ran from 22 May to 25 August (year 1) and from 5 June to 5 September (year 2). During these periods, animals were weighed weekly and group food intake recorded daily. At the end of winter animals were moved outside onto pasture and weighed monthly until the end of spring (27 November, year 1 and 7 December, year 2). In year 2 weighing continued during summer, until 4 April. The animals were slaughtered on 28 November and 18 January (year 1) and 5 April (year 2). The effect of housing on live-weight gain (LWG) and dry-matter intake (DM1) in AL groups was not significant in either year. However in R groups, O had a higher DMI than I in both years (P < 0·05) and a higher LWG than I in year 1 (P < 0·05). LWG was loiver in R than in AL groups in winter in year 1 (P < 0·05) and year 2 (P < 0·001) and live weight was lower in R than in AL groups at the end of winter in both years. Live weight was still lower in R than in AL groups at the end of spring in both years (P < 0·01). In year 2, this live-weight difference was not significant by the end of summer. Hot carcass weight (HCW) was greater in AL animals than R animals (P < 0·05) and dressing proportion was higher in R than in AL (P < 0·05) in year 1. GR (an index of body fatness) was greater (P < 0·05) in O than I in year 1 and was greater (P < 0·05) in AL than in R animals in year 2. Differences in GR between treatments were not significant in either year, with HCW as a covariate.In conclusion, housing calves given food ad libitum during winter did not reduce DMI or increase growth rate. When normal growth rates were prevented by restricting food intake, housing lowered DMI requirement, although such a situation is unlikely to be a useful farm management practice as recovery from the growth check was slow. Annual variations in climate may determine both the food savings made by housing and the extent of compensatory growth of food-restricted animals in spring.
Effect of the β-adrenergic agonist cimaterol and dietary protein level on fat young sheep given diets containing submaintenance levels of dietary energy
Authors: Galbraith H. , Minassie B. , Scaife J. R. 
Published: September 2010

AbstractThirty Suffolk cross wether sheep aged about 12 months and weighing 57 kg on average were used. They had been given previously a high energy diet to produce a fat body condition and average condition score of 3·7. Animals were allocated to an initial slaughter group (IS) or to four dietary treatment groups (UL, UH, CL and CH) based on sugar-beet feed (L) or white-fish meal (H) supplemented with chopped straw and pelleted, without (UL and UH) or with (CL and CH) the β-adrenergic agonist cimaterol, to provide an estimated 20 g (L) or 130 g (H) rumen undegradable protein per kg dry matter (DM). The sheep were offered 0·3 kg of the appropriate pelleted diet in addition to 200 to 400 g of chopped barley straw to provide proportionately 0·7 of the estimated metabolizable energy requirement for maintenance and, where appropriate, 2·5 mg cimaterol per day. Comparisons were made for the main effects of dietary protein intake and cimaterol and interactions between dietary protein and cimaterol.The animals on dietary treatments were slaughtered after 49 days. The animals exhibited variable reductions in live weight and weights of carcass and non-carcass components in comparison with the IS group and in response to restricted dietary energy intake. The only effect due to the elevated dietary protein provision was a smaller loss in live weight compared with the low protein diet. In contrast, compared with responses recorded in its absence, treatment with cimaterol resulted in significantly greater values for weights of cold carcass, cross-sectional area o/m. longissimus dorsi and weights of DM, crude protein and ash in the carcass with significantly smaller weights for raw fleece. In comparison with the IS group, significantly smaller changes due to cimaterol were recorded for the weights of carcass crude protein and ash. Cimaterol treatment significantly increased the weight loss of fat in the carcass and in the perirenal and retroperitoneal, but not omental, depots as components of fleece-free non-carcass fat which was also significantly reduced in total. Interactions suggested that losses in carcass weight and DM in the presence of cimaterol were less and gains in carcass protein and ash greater, on the high than on the low protein diet. The results suggest that under conditions of energy undernutrition cimaterol may induce smaller losses or larger gains in carcass but not non-carcass, crude protein at the expense of fat depletion in carcass and non-carcass fat depots.
An association of haemoglobin protein (HBB) with ovulation rate in Cambridge sheep
Authors: Glazko V. I. , Owen J. B. , Dewi I. Ap , Axford R. F. E. 
Published: September 2010

AbstractBlood from 106 females (1 to 7 years old) of the Cambridge flock at the University of Wales, Bangor was analysed for 21 protein systems. Of the 11 polymorphic systems, haemoglobin protein (HBB) was found to be significantly associated with ovulation rate as measured by mean ovulation rate for all records per ewe. Mean ovulation rate for the HBB AA genotype was 1·25 ovulations higher than for the AB and BB genotypes(P < 0·001).The results suggest that a gene segregating in this breed is different from the Booroola (FecB) gene and that lambs of either sex can be screened at a young age for a major difference in ovulation rate.
Evaluation of the efficiency of alternative selection schemes and breeding objectives in dairy sheep of Greece
Authors: Kominakis A. , Nitter G. , Fewson D. , Rogdakis E. 
Published: September 2010

AbstractThe genetic and economic efficiency of alternative selection schemes and breeding objectives for the Karagouniki dairy sheep in Greece was investigated by model calculations. Criteria of efficiency were the annual genetic gain for the aggregate breeding value, the profit per ewe in the population and the annual selection responses for single traits. The introduction of a two-tier selection scheme, where the recorded ewes are separated into a nucleus and a pre-nucleus, was found superior in both genetic and economic terms for a breeding objective comprising the traits milk yield and number of lambs weaned per ewe per annum. Highest rates for annual genetic gain and selection responses were obtained when the nucleus size was proportionately 0·05 of the population (200 000 ewes), the size of the test matings 0·50 to 0·60 of the size of the pre-nucleus unit (0·10 of the population) and the number of daughters per test ram 40. Opening the nucleus to replacement ewes from the lower tier did not affect positively the annual genetic gain and the selection responses. Furthermore, a breeding objective comprising the traits fat yield and number of lambs weaned per ewe and per annum was found very efficient in both genetic and economic terms while selection on growth and carcass traits did not seem to be justified.
Estimating the metabolizable energy requirement for pregnancy in sheep
Authors: Hutchings N. J. 
Published: September 2010

AbstractA model is developed in which the metabolizable energy (ME) requirement for growth and maintenance of the foetus, uterus and udder are described explicitly for sheep. The efficiency of the use of ME for the growth of the products of conception (kp) is assumed to be the same as that for growth in non-pregnant animals. Using the results from the model to calculate the efficiency of the use of ME for conceptus growth (kc) in the conventional manner yields values with a similar magnitude and similar variation with food quality as those estimated experimentally. It is concluded that separately accounting for the growth and maintenance of the foetus, uterus and udder is preferable in models but unnecessary in feeding standards.
The effect of different concentrations of protein and fat in milk replacers on protein utilization in kid goats
Authors: Sampelayo M. R. Sanz , Mariscal I. Ruiz , Extremera F. Gil , Boza J. 
Published: September 2010

AbstractThe efficiency of utilization of protein for retention was analysed in pre-ruminant kid goats of the Granadina breed. Sixty male kids were used. Six were slaughtered at birth and the remaining 54 were offered different protein and fat intakes using nine different milk replacers. The protein concentrations were 200, 240 and 280g/kg dry matter (DM) and those of fat were 200, 240 and 280 g/kg DM. Animals were maintained on experiment until they were 60 days old. All were slaughtered on day 61. Nitrogen (N) balance trials were performed during the last 8 days of the 1st and 2nd months. Body composition of the animals slaughtered at birth and at 61 days were determined. Rates of energy retained as protein and as fat were determined (kJ/kg M0·75 per day) and the corresponding rates of metabolizable energy intake as protein and as fat (kJ/kg M0·75 per day) estimated.Once the relationships between the rates ofN retained and those of digestible N ingested had been established, it was evident that by increasing the protein content of the diet the efficiency of protein retention was decreased. In contrast, increasing the fat content of the milk replacer increased the efficiency of protein retention. The latter effect was noted for the milk replacers containing the high and medium levels of protein but not for those that contained the lowest level of protein, indicating that the level of protein was then the limiting factor. Having recorded this protein-sparing effect of the fat, the results obtained from the slaughter trials were used to develop generalized equations expressing the rates of energy retention in the form of protein or fat as a function of the rates of metabolizable energy intake achieved as both protein and fat. From the analysis of these equations conclusions are drawn about the variable contribution to protein retention in these animals of energy ingested as fat. This contribution depended on the energy intake achieved both in the form of protein and in the form of fat.
The effect of protein source on lameness and solear lesion formation in dairy cattle
Authors: Offer J. E. , Logue D. N. , Roberts D. J. 
Published: September 2010

AbstractTwo groups of 16 cubicle-housed Holstein-Friesian cattle from weeks 3 to 27 of lactation were offered either a proprietary protein supplement of animal origin (P) or soya-bean meal (S) as the protein source in the concentrate in a continuous design experiment. Concentrates were offered mixed with grass silage as complete diets to give a forage: concentrate ratio of 41: 59 and a crude protein content of 213 and 210 g/kg dry matter (DM) and a metabolizable energy content (MJ/kg DM) of 11·9 and 12·0 for P and S respectively. There was no significant difference due to diet for mean locomotion score (1·75 v. 1·66 (s.e. 0·15)), prevalence (0·1 v. 0·09 per cow per week) or incidence of lameness (0·04 v. 0·04) for P and S respectively. Similarly there was no effect on hoof growth, wear, hardness or conformation. Sole haemorrhages, indicative of subclinical laminitis, were observed throughout the experiment but were most severe at approximately 16 weeks after calving. Levels of heel erosion remained constant throughout. There was no significant effect of treatment on either heel or sole lesion formation. No significant differences were observed between treatments for milk yield, live weight, condition score or blood metabolites. The conclusions from this study were that source of dietary protein has no effect on dairy cow lameness or the development of sole lesions indicative of subclinical laminitis.