bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of altering the hay to concentrate ratio and concentrate composition on the rumen fermentation of dry sheep and milk production of lactating dairy ewes
Authors: Zervas G. , Zarkadas L. , Koutsotolis K. , Goulas C. , Mantzios A. 
Published: August 2016

AbstractIn order to examine the effects of diets, with two hay to concentrate ratios and two forms of concentrates on the rumen fermentation of dry sheep and milk production of lactating ewes, three trials were conducted.In the first trial, four wether sheep, each fitted with a rumen cannula, were used in a 4 × 4 Latin-square design, by allocating them to one of four diets with different hay to concentrate ratio and concentrate type. The diets consisted of 0·5 kg hay and 0·75 kg either starchy (HRSC) or fibrous (HRFC) concentrates, or 0·25 kg hay and 1·0 kg either starchy (LRSC) or fibrous (LRFC) concentrates. The diets were designed to provide similar intakes of energy and crude protein. Volatile fatty acids (VFA) and ammonia concentrations, pH values and number of protozoa were determined in wether rumen fluid.Total VFA concentration was not significantly affected by diet but acetate and n-butyrate proportions were higher (P < 0·002) on the higher forage diets and propionate higher (P < 0·002) on the lower forage diets. pH values and number of protozoa in sheep rumen fluid were unaffected by treatment, while ammonia concentration was lower (P < 0·05) on the HRFC diet.In the second trial, 60 lactating dairy ewes were allocated to one of four diets for weeks 11 to 15 of lactation (period 1). Ewes were given food daily: 0·87 kg hay and 1·3 kg either HRFC or HRSC concentrates, or 0·4 kg hay and 1·6 kg either LRFC or LRSC concentrates. During weeks 16 to 20 of lactation (period 2), the ewes were given the same amount and type of concentrates but hay was supplied ad libitum and this period formed the third trial.Milk yield and milk composition were affected significantly by hay to concentrate ratio with the lower hay to concentrate ratio resulting in a significant increase in milk yield, milk protein efficiency, protein content and protein and lactose yields. Milk fat content and yield were reduced. Hay intake was proportionately greater (P < 0·002) by 0·15 to 0·20 with starchy than with fibrous concentrate diets in period 2. Problems such as acidosis or ‘off-food’ periods in ewes given the low hay to concentrate ratio diets were not observed, irrespective of concentrate type.
Time trends of Gompertz growth parameters in ‘meat-type’ pigs
Authors: Knap P. W. 
Published: August 2016

AbstractPreviously published data from serial slaughter trials on growing pigs of five genotypes were reanalysed. Gompertz curves were fitted to body protein and lipid mass in order to estimate mature protein and lipid mass (P∞,L∞) and the rate parameter (BGompJ that was presumed to be equal for the protein and lipid curves.L∞was expressed as its ratio toP∞, RL∞P∞. The maximum rate of protein deposition was derived as Pdep,max= P∞X BGomp/e. The analysed data encompass body weights of 10 to 133 kg, 13 to 217 kg, 18 to 106 kg, 20 to 110 kg and 11 to 145 kg. The Gompertz function fitted all data sets well, as judged by the standard deviations and distribution patterns of the residual terms. Autocorrelations among the residuals were non-significant.Averaged over sexes (females and entire and castrated males), the P estimates were all close to 31 kg; the RL∞/P∞estmates ranged from 1·4 to 4·7 kg/kg; the BGompestimates ranged from 0·009 to 0·017 kg/day per kg. The resulting Pdep,max estimates ranged from 110 to 193 g/day. The genotypes were placed in 1969, 1976, 1984, 1990 and 1993. Plotting the estimates against time (year) showed distinct time trends for all parameters except P∞. RL∞/P∞seems to gradually reach a plateau around unity, whereas BGompand Pdep/max increase linearly. These trends were confirmed by an analysis of body weight based on the same data plus data on three other genotypes that spanned the same time period. Analyses of the same protein and lipid data to fit a sigmoid growth function with a flexible point of inflexion did not change the apparently absent time trend of F. The estimates of the inflexion points of the fitted protein accretion curves, expressed as proportions ofF, were indistinguishable from the fixed 0·368 value of the Gompertz function for the earliest three genotypes and then showed a tendency to increase, up to 0·46 for the 1993 population. These time trends must be the consequence of a combination of changes in nutritional and other environmental factors and genetic changes. They cannot be the sole result of within-line selection for growth and body composition traits, since this should increase P∞. It seems as if pig breeders have repeatedly initiated their sire lines from genetic resources with small mature size, to subsequently increase this trait as an indirect result of within-line selection.
Effect of forage to concentrate ratio in the diet on ruminal fermentation and digesta flow kinetics in sheep offered food at a fixed and restricted level of intake
Authors: Carro M. D. , Valdés C. , Ranilla M. J. , González J. S. 
Published: August 2016

AbstractThe effects of four diets differing in their for age: concentrate ratio (80:20, 60:40, 40: 60 and 20:80; g/100 g fresh matter) on rumen characteristics, digestibility and digesta flow kinetics were investigated. Alfalfa hay was used as forage and concentrate was composed of barley, soya-bean meal and maize. Diets were prepared by mixing all ingredients and offered to the animals as complete diets. Eight mature Merino sheep, each fitted with a rumen cannula, were offered 1·055 kg dry matter per day of the corresponding diet over two experimental periods. The daily evolution of ruminai pH, volatile fatty acids (VFA) and ammonia nitrogen (N) concentrations were measured. Digestibility was determined by total faecal collection and Cr and Co were used as markers to estimate digesta passage rates. Microbial nitrogen flow at the duodenum (MNDF) was estimated from the urinary excretion of purine derivatives (PD). The apparent digestibility of organic matter increased (P< 0·001) whereas that of all fibrous fractions decreased linearly (P< 0·05) as the proportion of concentrate in the diet increased. Rumen pH decreased linearly (P< 0·001) with increasing proportions of concentrate but total VFA concentrations were unaffected by changes in the diet (P> 0·05). Both liquid and solid digesta outflow rates from the rumen decreased quadratically (P< 0·01) as the proportion of concentrate in the diet increased. The urinary excretion of total N, urea-N and ammonia-N was unaffected (P> 0·05) by changes in the diet. In contrast, the daily urinary excretion of both allantoin and total PD increased quadratically (P< 0·05) with increasing proportions of concentrate. Consequently, the estimated MNDF increased linearly (P< 0·001) from 9·9 g/day on the high forage diet to 14·5 g/day on the high concentrate diet.
Dynamic selection for maximizing response with constrained inbreeding in schemes with overlapping generations
Authors: Grundy B. , Villanueva B. , Woolliams J. A. 
Published: August 2016

AbstractA dynamic selection algorithm for maximizing annual genetic response while constraining the rate of inbreeding per generation in populations with overlapping generations is presented. The procedure gives the optimum number of individuals to be selected and the progeny they each produce. The solution to the problem was obtained by using BLUP estimated breeding values, the augmented numerator relationship matrix and lifetime breeding profiles. The procedure was able to constrain the rate of inbreeding per generation to a predefined level across generations of selection by considering all gene flow pathways. The optimization procedure represents an improvement on standard truncation BLUP selection, as it yielded substantially more genetic response (up to 35%) at the same rate of inbreeding.
Relationship between dry matter, fibre and nitrogen degradation characteristics of silage and silage intake of steers
Authors: Dawson L.E.R. , Street R.W.J. 
Published: August 2016

AbstractA study was carried out to examine the relationship between silage intake and rumen degradability characteristics of silage. The dry matter (DM), neutral-detergent fibre (NDF), acid-detergent fibre (ADF), hemicellulose and nitrogen (N) degradability characteristics of 136 silages were determined using polyester bags in three rumen fistulated beef cross steers. The bags were incubated for 0, 6, 12, 24, 48 and 72 h. Intakes of these silages, by steers, were reported by Steen et al., 1998. The relationships between silage DM intake (g/kg metabolic live weight) and DM, fibre and N degradability characteristics of the silages were poor (R2 < 0·32). Degradability characteristics of the silages were highly negatively correlated with fibre concentration of the silages (R < –0·82) and highly positively correlated with the soluble N minus ammonia concentration (R < 0·77). Some of the degradability characteristics were highly correlated with organic matter digestibility, particularly the proportion of DM, fibre and N degraded after 72 h (R = 0·75 to 0·85). In view of the poor relationship between silage intake and degradability, the results of this study question the rôle of degradation characteristics of DM, fibre and N in the rumen on silage intake.
Association between gene polymorphism of growth hormone and carcass traits in dairy bulls
Authors: Grochowska R. , Lundén A. , Zwierzchowski L. , Snochowski M. , Oprządek J. 
Published: August 2016

AbstractThe contribution of the leucine/valine substitution at amino acid position 127 in the bovine growth hormone (GH) protein to variation in carcass traits was studied. The data included 109 Polish Friesian bulls slaughtered at 15 months of age. The traits measured were carcass gain, weights of meat, bones, intermuscular and subcutaneous fat in the carcass and meat, bones and fat in valuable cuts (fore and best ribs, sirloin, round of beef and shoulder). The bulls’ GH genotype was determined using the PCR-RFLP technique. The frequencies of leucine (Leu) and valine (Val) alleles were 0·64 and 0·36, respectively. The GH concentration was determined in serial blood plasma samples collected every 15 min starting from 15 min before to 135 min after intravenous administration of 0·15 µg thyrotropin releasing hormone (TRH) per kg live weight. Response GH variables were: baseline (the mean of samples collected at –15 and 0 min), peak (the sample taken at 15 min post injection of TRH) and disappearance rate (calculated as peak minus the sample at 60 min, divided by time interval 45 min). Mixed animal models were used for the statistical analysis. Differences were found between the Leu/Leu and the Val/Val genotypes for carcass gain and weight of meat in the carcass (P≤ 0·05). Moreover, differences in the size of the GH peak between the two homozygotes approached significance (P≤ 0·10). The effect of GH genotype accounted for a moderate part of the phenotypic variance in the carcass traits, corresponding to a reduction in the residual variance of ≤ 5·25% when included in the model, whereas the corresponding value for the effect of GH genotype on the variation in GH release was lower, ≤ 1·77%. In conclusion, the Leu/Val polymorphism seems to be associated with carcass traits in dairy bulls, although the effect was relatively small when compared with the effects of season and background genome.
Effects of type and treatment of grain and protein source on dairy cow performance
Authors: Khalili H. , Sairanen A. , Hissa K. , Huhtanen P. 
Published: August 2016

AbstractThe effects of different types of energy or protein supplementation on performance of cows given grass silage-based diets were studied. The possibility of maintaining high energy intakes by using different grain sources, barley or maize, or by the use of the physical processing of the barley was investigated. In addition, the relative quality of rapeseed meal as a protein supplement compared with alternative protein supplements was examined. In experiment 1 16 Finnish Holstein-Friesian cows were used in a cyclic change-over design experiment with eight diets and four 21- day periods. The concentrate supplements comprised a 2 ✕ 2 ✕ 2 factorial arrangement of two grain sources (barley (B) and maize (M)) given either ground (T–) or steam-rolled (T+), each supplemented with either rapeseed expeller (R) or a mixture of maize gluten and soya-bean meal (GS). Grass silage was givenad libitumand concentrates at a rate of 11·2 kg DM per day. M supplements increased milk, milk protein and lactose output (P< 0·05) and decreased milk urea concentration (P< 0·01) compared with B supplements. Blood β-hydroxy-butyrate (BHB) and plasma urea concentrations were higher (P< 0·01) for B than M diets. R supplements increased silage intake, energy-corrected milk yield and milk protein output and concentration (P< 0·05) compared with GS supplements. Steam-rolled grain decreased food intake, blood BHB (P< 0·05) and plasma and milk urea concentrations (P< 0·001). Steam rolling improved organic matter digestibility (grain ✕ processing interaction,P< 0·05) with M but not with B supplements.In experiment 2 four Finnish Holstein-Friesian cows fitted with rumen cannula were used in a balanced complete change-over design to evaluate ground or steam-rolled barley (T– v. T+) and two protein treatments (rapeseed expeller, R or a mixture of maize gluten/soya-bean meal/sugar beet solubles, GSS). Cows were given concentrates at 11·2 kg dry matter (DM) per day and offered grass silagead libitum. There were no differences (P> 0·05) in food intake, digestibility or milk production and composition between treatments. Plasma urea concentrations (P< 0·01) and molar proportion of butyrate (P< 0·05) in rumen fluid were decreased with R compared with GSS supplements. The results showed that replacing B with M grain resulted in minor increases in milk production. Steam rolling of grain did not influence animal performance. Among the protein supplements R increased animal performance compared with GS supplement.
Genetic parameters of weights, ultrasonic muscle and fat depths, maternal effects and reproductive traits in Welsh Mountain sheep
Authors: Dewi I. Ap , Saatci M. , Ulutas Z. 
Published: August 2016

AbstractGenetic parameters of weight traits, ultrasonic fat and muscle depths, maternal effects and reproductive traits of Welsh Mountain sheep were estimated based on analyses of data from the nucleus flock of a cooperative breeding scheme. The traits analysed were 12 week weight (TW, no. = 11201), mature weight (MW, no. = 2376), weight at scanning (SW, no. = 1022), muscle depth (SM, no. = 1024), fat depth (SF, no. = 1024), litter weaning weight (LW, no. = 3445) and litter size (LS, no. = 3445). (Co)variance components were estimated in univariate and bivariate animal models. Heritability estimates from univariate analyses were 0.16, 0·49, 0·29, 0·24, 0·22, 0·20 and 0.15 for TW, MW, SW, SF, SM, LW and LS respectively. Genetic correlations among the weight traits were high. There was no detectable correlation between SF and SM. SF and SM were strongly correlated with SW but not with the other weight traits. LW was strongly correlated with MW and SW but not with TW, although the latter analysis was inconclusive. Maternal heritability was similar (0·11) for the univariate analysis of TW and all bivariate analyses involving TW (except for TW v. LW). The permanent environmental effect of dam was generally low (0.02 to 0.04) whilst litter effects were generally high (0·20 to 0·23). The correlation between direct and maternal genetic effects for TW were generally small and non-significant. The maternal genetic effect for TW was moderately correlated with the direct additive effect for MW and SW but was not significantly correlated with the direct additive effect for LS, SM or SF. A very large positive correlation was found between the maternal genetic effect for TW and the direct additive effect for LW. The implications of the results are discussed in the context of selection indices for Welsh Mountain sheep.
Effect of high ambient temperature on protein and lipid deposition and energy utilization in growing pigs
Authors: Bellego L. Le , van Milgen J. , Noblet J. 
Published: August 2016

AbstractThe effects of high ambient temperature (T) on protein (PD) and lipid deposition (LD) and energy utilization were studied on 36 Piétrain ✕ (Landrace ✕ Large White) barrows according to a factorial design including two temperatures (23ºC for thermoneutrality and 30ºC for the high temperature) and four feeding levels. One feeding level corresponded to the voluntary food intake (VFI) at each temperature. Expressed as proportion of VFI at 23ºC, the actual feeding levels were 1·00, 0·90, 0·80, 0·70 at 23ºC and 0·80, 0·73, 0·68 and 0·62 at 30ºC. Animals were offered a wheat, maize and soya-bean meal based diet containing 187 g crude protein per kg and 0·95 g ileal standardized digestible lysine per MJ of net energy. Pigs were housed individually and had free access to water. The experiment started at 24 kg live weight and animals were slaughtered at 65 kg live weight and their body composition was measured. Slaughter of nine control pigs at the beginning of the experiment allowed calculation of the composition of gain (nutrients and energy) according to the comparative slaughter technique. Reduction of metabolizable energy (ME) intake resulted in a reduced live-weight gain at each T: the maximum gain was 1052 g/ day in pigs offered food ad libitum at 23ºC and the minimum (760 g/day) at the lowest intake at 30ºC. Visceral organ mass was lower at 30ºC than at 23ºC but was not affected by feeding level within T. Growth responses were described as polynomial or broken-line functions of ME intake (linear-plateau for PD). Both the slope and the plateau were influenced by T. At 30ºC, PDmax (143 g/day) was reached at 22·8 MJ ME per day, while at 23ºC PDmax (165 g/day) was reached at 28·4 MJ ME per day. In both cases, PDmax was reached at 0·88 of VFI at this temperature. Also the marginal response of PD to ME intake before the breakpoint was affected by T (5·9 and 4·5 g PD per MJ ME at 23ºC and 30ºC, respectively). At identical high ME intake (e.g. 0·80 of VFI at 23ºC), PD was greater at 23ºC than at 30ºC. In contrast, severe food restriction reduced PD at thermoneutrality more than an identical food restriction obtained at high ambient T. The results indicate that heat stress has a direct negative effect on PD and affects the partitioning of energy gain between protein and fat deposition.
Detection of a major gene for litter size in Thoka Cheviot sheep using Bayesian segregation analyses
Authors: Walling G. A. , Bishop S. C. , Pong-Wong R. , Gittus G. , Russel A.J. F. , Rhind S. M. 
Published: August 2016

AbstractSegregation analyses were applied to data from an experimental sheep flock to investigate the presence of a major gene affecting litter size. The data set contained 14 years of litter size data, with up to five parities per ewe, from Cheviot sheep carrying the putative Thoka fecundity gene from Icelandic sheep. Segregation analyses were performed using a Markov chain Monte Carlo method implemented using Gibbs sampling. Uniform priors were initially used for estimating variance components, the gene effect and fixed effects in the data. Genotypes in the base generation were assumed known based on the use of the imported Icelandic donor semen from the founder rams. The use of alternative priors (naïve and inverse-gamma distributions) for the variance components did not significantly affect the results, demonstrating the data to be sufficiently powerful for the analyses used. Segregation analyses detected a major gene for litter size in the Thoka Cheviot flock increasing litter size by 0·70 lambs per ewe lambing for a single copy of the gene. When the analysis was repeated without fixing the genotypes in the base population, the analyses predicted a different genotype than that previously used for one of the founder rams and suggested the major gene to be segregating in the Cheviot founder animals prior to the introduction of the Thoka rams. A liability threshold analysis was also applied to the data. As identified in other studies, the threshold analysis overestimated the heritability, but the estimated major gene effect was not significantly different from other analyses. The results confirm the segregation of the Thoka gene in a Cheviot flock and highlight the statistical method as a useful tool for identifying carrier animals to be used for future matings.
Effect of tail docking in Awassi lambs on metabolizable energy requirements and chemical composition of carcasses
Authors: Al Jassim R. A. M. , Brown G. , Salman E. D. , Abodabos A. 
Published: August 2016

AbstractThe effect of tail docking on metabolizable energy requirements and carcass characteristics was studied using 80 weaned entire Awassi male lambs. Docking was performed within 3 days of birth and lambs were weaned at 90 days old. Docked and undocked lambs were randomly allocated to four groups, individually penned and offered different amounts of a pelleted concentrate diet. The pelleted diet was estimated to contain 11·8 MJ of metabolizable energy (ME) and 182 g of crude protein (CP) per kg dry matter (DM). Lambs on the high levels of intake were slaughtered at a target weight of approximately 45 kg. Other lambs were maintained on the diet for 149 days before being slaughtered. The right sides of all carcasses were cut into standardized commercial cuts then dissected into muscle, fat and bone. The soft tissue was pooled and analysed for DM, C P, ash and fat. Prediction of live-weight gain (LWG) and empty body gain for a given ME intake (MEI) was made using the growth and MEI data. MEI was expressed as MJ per kg metabolic body weight (M 0·75) per day. Tail docking had no effect (P > 0·05) on lamb growth from birth to weaning. During the post-weaning growth period, LWG and empty body gain were significantly higher (P < 0·05) for undocked lambs than docked lambs, at feeding levels between 0·31 and 0·52 MJ/kg M 0·75 per day and similar (P > 0·05) at high levels of intakes (between 0·74 and 1·1 MJ/ kg M 0·75 per day). Hot and cold carcass weights were similar (P > 0·05) for the two groups. Differences in empty body weight and fleece-free empty body weight were significant (P < 0·05) only for the 0·443 to 0·522 MJ/kg M 0·75 per day level of ME intake. Predicted ME requirements were higher for docked lambs for an estimated LWG between 0 and 100 g/day and lower for higher LWG (125 to 225 g/day). Docking had no effect (P > 0·05) on food conversion efficiency (FCE). Carcasses from docked lambs had significantly lower (P < 0·001) internal plus tail fat. Pooled soft tissue excluding tail fat, for the undocked lambs contained significantly more (P < 0·01) protein, less (P < 0·001) fat, higher (P < 0·01) moisture and similar (P > 0·05) ash content.