bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in muscularity with growth and its relationship with other carcass traits in three terminal sire breeds of sheep
Authors: Jones H. E. , Lewis R. M. , Young M. J. , Wolf B. T. , Warkup C. C. 
Published: August 2016

AbstractData were available for 160 sheep (50 Suffolk males, 50 Suffolk females, 40 Texel males and 20 Charollais males). One-fifth of animals within each breed and sex were slaughtered at each of 14, 18 or 22 weeks of age and two-fifths slaughtered at 26 weeks. After slaughter linear measurements were taken on the carcass. The left side of each carcass was then separated into eight joints and each joint dissected into lean, bone and fat. Five muscularity measures (three for the longissimus thoracis et lumborum (LTL) muscle, one for the hind leg and one for the whole carcass) and one of the shape of the LTL cross-section (depth: width) were calculated. With the exception of one measure for the LTL, muscularity increased with growth. Rates of increase in most measures were higher in Texels than in each of the other breeds, but were not different between the male and female Suffolks or between the Suffolk and Charollais lambs. Increases in most muscularity measures at a constant live weight were associated with increases in lean to bone ratio and carcass lean content. Associations with fat content were either non-significant or negative. Relationships with lean distribution were non-significant or weak. Correlations between the three measures of muscularity for the LTL were high. Correlations between the whole carcass measure and those within different regions were moderate to high in the Texels but lower in the Suffolk and Charollais breeds. The same was true for correlations between the LTL measures and hind leg muscularity. If muscularity throughout the carcass is to be described effectively, measures in more than one region may be required, particularly in the Suffolk and Charollais breeds.
Meal patterns of dairy cows consuming mixed foods with a high or a low ratio of concentrate to grass silage
Authors: Tolkamp B. J. , Friggens N. C. , Emmans G. C. , Kyriazakis I. , Oldham J. D. 
Published: August 2016

AbstractWith the aim of testing the effects of food quality on meal patterns 127 213 visits by 22 lactating cows to 12 computerized feeders supplying two foods, high forage (HF) and high concentrate (HC) consisting of grass silage and concentrate were analysed. The foods were composed of the same ingredients but the proportion of concentrate dry matter (DM) in the food DM differed between HC (0·59) and HF (0·27). Each of the foods was offered ad libitum to 11 cows from the start of lactation until 156 (s.e. 9) days after calving. Mean daily fresh food intake (49·2 kg) was not affected by treatment. Mean daily intake of DM differed between HC (23·6 kg) and HF (17·8 kg). After estimating individual meal criteria, visits were grouped into meals. The mean daily number of meals was 6·6, the mean fresh food intake per meal was 7·6 kg and neither was affected by treatment. Cows consuming HF had longer meals (41·4 v. 31·3 min) but a lower feeding rate than cows consuming HC (233 v. 337 g of fresh food per min and 78 v. 156 g DM per min). Pre- and post-prandial correlation coefficients were sometimes statistically significant but always low (R2from 0 to 0·05) and not affected by treatment. Food intake per hour of the feeding cycle (defined as the intake during a meal divided by length of the meal plus the duration of the preceding between-meal interval) showed a diurnal pattern in the shape of a sine-wave with low values of about 1·5 kg/h for cycles starting just after midnight and high values of more than 3·0 kg/h for cycles starting just after noon. Neither the mean, nor the amplitude, nor the shift of the sine-wave were affected by treatment. The data suggest that similar mechanisms are responsible for the short-term intake regulation of HC and HF. No evidence was found to suggest that the diurnal meal pattern of cows consuming HF deviated from that of cows consuming HC as a result of differences between foods in constraints related to their physical properties.
Growth performance and carcass characteristics of two genotypes of growing-finishing pig in three different housing systems
Authors: Guy J. H. , Rowlinson P. , Chadwick J. P. , Ellis M. 
Published: August 2016

AbstractA trial was conducted to compare the growth performance and carcass characteristics of 720 growing pigs housed in one of three different finishing systems: outdoor paddocks, straw yards and fully slatted pens. Two genotypes were used: ‘indoor’ (progeny of Large White ✕ Landrace sows mated to Large White boars) or ‘outdoor’ (progeny of part-Duroc or part-Meishan sows, mated to Large White boars). Groups of 20 pigs were reared from an average of 30 to 80 kg live weight and given ad libitum access to a commercial specification diet. The outdoor genotypes had significantly lower average daily gain than the indoor genotype (682, 673 and 719 g respectively for part-Duroc, part-Meishan and indoor-type pigs, P 0·01). Part-Meishan genotypes had significantly higher backfat levels than the indoor genotype (P 0·05), with an intermediate value for part-Duroc pigs (22·6, 21·1 and 21·8 mm respectively). Values for food conversion ratio were significantly higher for combined outdoor genotype groups when compared with the indoor genotype (2·76 v. jt>2·62, P 0·05). Average daily gains of pigs in straw yards and outdoor paddocks were significantly higher than for those in fully slatted pens (736 and 675 v. 627 g, P 0·01 respectively). Food conversion ratio was similar for pigs in outdoor paddocks and fully slatted pens, but significantly lower for those in straw yards (2·77 and 2·75 v. 2·55, P 0·01 respectively). Backfat depth (P1 + P3mm) was significantly greater for animals finished in straw yards compared to those in outdoor paddocks (22·2 v. 20·6 mm, P 0·05) and intermediate for those finished in fully slatted pens (21·5 mm). Interaction between finishing system and genotype did not occur to any major degree, hence it appears unnecessary to specify a particular genotype for a particular finishing system. It was concluded that pigs of the outdoor genotype had a lower growth performance compared with the indoor genotype. Finishing systems however may have been confounded by other factors so that no clear recommendations can be made as to the optimum finishing system.
Genotype by environment interactions in lamb weight and carcass composition traits
Authors: Maniatis N. , Pollott G. E. 
Published: August 2016

AbstractThe systematic use of the same genotype in several different environments provides information that can be used to estimate genotype by environment interaction (G ✕ E) variances and parameters. Data from the UK Suffolk Sire Referencing Scheme Ltd were used to investigate a range of sire and dam by environment interactions in lamb weight (at 8 weeks and scanning) and body composition traits (muscle and fat depth). These interactions were calculated in a DFREML mixed model containing direct additive, maternal additive, maternal environmental random variance components and the covariance between direct and maternal additive effects. Sire interactions with year, flock and flock-year and dam effects within and between litters were investigated. The addition of all G ✕ E (co)variance components resulted in an improved fit of the model for all traits. Sire interactions accounted for between 2 and 3% of the phenotypic variance in all traits, usually at the expense of both additive effects. Maternal litter environmental variance components ranged from 10% (fat depth and muscle depth) to 20% (8-week weight) of phenotypic variance. Most of this variation was found in the residual component of variance when the term was omitted from the model. When fitting sire G✕ E components in a model the covariance between direct and maternal additive genetic effects, as a proportion of phenotypic variance, was reduced to a low level (from –0·36 to –0·08 for 8-week weight). Genotype by environment interactions form a significant source of variation in lamb growth and composition traits and reduce the high negative correlation between additive effects found previously in these traits.
The effect of melatonin treatment on fur maturation period and hair follicle cycle in growing chinchillas
Authors: Lanszki J. , Allain D. , Thébault R.-G. , Szendrö Zs. 
Published: August 2016

AbstractThe effect of melatonin treatment on fur maturation period and hair follicle cycle in 4-month-old male and female chinchillas, kept under conditions of natural photoperiod, was studied. The animals were treated with continuous-release implants of melatonin (18 mg, group M, no. = 56), while no treatment was given to the control (group C, no. = 69). The effect on hair follicle activity cycle under conditions of normal hair growth (no. = 8) and after defleecing (no. = 8) and on number of hair fibres per follicle bundle (no. = 27) were measured by taking skin samples for histological examination once a month. The age at fur priming was reduced by 31 days (P < 0001) in the melatonin-treated chinchillas. When moulting began during the short-day period, the fur reached maturity 13 days (P < 005) sooner than when the moult began during the long-day period. Melatonin administration proved to be effective in these two periods. Melatonin treatment led to hair follicle activity decreasing at a faster rate, and the differences between treated and control groups from day 60 were significant (P < 005). The primary and secondary hair follicles reached the telogen phase 30 days earlier. Due to melatonin administration more fibres per follicle bundle were observed on the matured pelt (P < 005). At 4 months of age, following the removal of hair by defleecing, the growth of the first adult hair was studied without the presence of young-age hairs. No influence of defleecing as opposed to normal hair development on age at fur maturation or on the number of fibres per hair follicle bundle was observed. Within groups M and C the number of fibres per hair follicle bundle proved to be independent of age at first fur priming. No substantial differences between the groups were observed with respect to either body weight or pelt length at the time of pelting. According to these results, melatonin administration is effective in shortening the coat maturation period in growing chinchillas and causing corresponding changes in the hair follicle cycle.
The influence of cow genetic merit for milk production on response to level of concentrate supplementation in a grass-based system
Authors: Kennedy J. , Dillon P. , Faverdin P. , Delaby L. , Buckley F. , Rath M. 
Published: August 2016

AbstractThe objective of this study was to investigate if there is a genotype ✕ feeding system interaction for milk production in Holstein-Friesian dairy cows. For this purpose, 48 high genetic merit (HM) and 48 medium genetic merit (MM) dairy cows, were used in a two (genotypes) ✕ three (levels of concentrate feeding) randomized-block design experiment in three consecutive years. In year 1, all animals were in their first lactation, while in year 2 and year 3, 18 and 12 first lactation cows replaced animals culled at the end of the previous lactation. A total of 66 cows remained in the study in the same feeding system for the 3-year duration of the study. Concentrate feeding levels were 376, 810 and 1540 kg per cow per lactation; these were identified as the LC, MC and HC feeding systems respectively. There was a separate farmlet for each feeding system; farmlets were managed so that pre-grazing and post-grazing herbage height were similar for all three feeding systems. When compared on treatment means there was a significant genotype ✕ feeding system interaction for fat yield, while for mean solid-corrected milk yield the interaction was close to statistical significance (P = 0·07). However, regression coefficients of both milk and protein yield on pedigree index for milk and protein yield were significantly different between the LC and the HC. The interaction between feeding system and the regression of both on pre-experimental milk and protein yield were close to statistical significance (P = 0·08 and P = 0·09 respectively). Outputs of milk, fat, protein and lactose were greater for the HM than the MM cows. Feeding system had a significant effect on milk, fat, protein and lactose yields. There was a significant genotype ✕ feeding system interaction for body condition score (BCS) at the end of lactation; the MM cows had a higher rate of body tissue repletion than the HM cows especially in the HC system. The results suggest that there is a genotype ✕ concentrate feeding level interaction and that feeding systems developed in the past for animals of lower genetic merit may require adaptation if they are to be optimal for higher genetic merit animals.
A comparison of a linear and proportional hazards approach to analyse discrete longevity data in dairy cows
Authors: Lubbers R. , Brotherstone S. , Ducrocq V.P. , Visscher P.M. 
Published: August 2016

AbstractThe objective of this study was to compare two methods for analysis of longevity in dairy cattle. The first method, currently used for routine genetic evaluation in the UK, uses a linear model to analyse lifespan, i.e. the number of lactations a cow has survived or is expected to survive. The second method was based on the concept of proportional hazard, i.e. modelling the conditional survival probability of a cow as a function of time. Comparisons were based on estimated heritabilities, ranking of estimated breeding values of sires, estimated effects of covariates used in the final models, and the distribution of residuals. The same data set, 21497 observations on the number of lactations cows had survived, was used for both analyses, even in the presence of censored observations. Cows in the data were progeny of 487 sires. Heritability estimates for lifespan or survival were approximately 0·06 for both methods, using the definition of heritability on a logarithmic scale for the proportional hazards model. Correlations between breeding values for sires were high, with absolute values ranging from 0·93 to 0·98, depending on the model fitted. It was concluded that it may be justified to use the standard Weibull model even for discrete time measures such as the number of completed lactations, but that more research is needed in the area of discrete time variates.
Modelling the relation between energy intake and protein and lipid deposition in growing pigs
Authors: Milgen J. van , Quiniou N. , Noblet J. 
Published: August 2016

AbstractWhen modelling the effect of a changing nutrient supply to growing animals, it is important to distinguish the individual response curve of an animal from the change in this response that may occur during growth. A data analysis model is proposed where, for an individual animal, the relation between protein deposition (PD) and metabolizable energy (ME) intake above maintenance (MEp) is curvilinear, so that PD intersects the origin and reaches its maximum at the maximum protein deposition rate (PDmax). An increase of MEp beyond that required to attain PDmax would not change PD. The MEp not used for protein synthesis can be used for lipid deposition (LD). The relation between PD and LD on the one hand and ME on the other hand can then be described as a function of the maintenance energy requirement (MEm), PDmax, the level of ME required to attain PDmax (F; as a multiple of MEm) and the energetic efficiencies of PD (kp) and LD (kf). Of these statistics, only kp and kf were assumed to be independent of body weight (BW), age or genotype. Variation in PDmax was described as a Gompertz function (of age) whereas variation in F was assumed a linear function of BW. Maintenance energy requirement was expressed as a power function of BW. To evaluate the model, 145 nitrogen and energy (indirect calorimetry) balances were obtained from three types of pigs (Large White castrated males (cLW) and Piétrain × Large White castrated males (cPP× ) and males (bPP×)) ranging in BW between 45 and 100 kg and housed under thermoneutral conditions. Animals were allotted to one of four energy levels ranging from 0·70 to 1·00 of ad libitum intake. The MEm was not different between genotypes (849 kJ/kg BW0·60) whereas the kp and kf were 0·56 and 0·75, respectively. For castrated animals on ad libitum intake, PDmax started limiting PD at approximately 130 days of age (78 and 86 kg BW for cLW and cPP×, respectively). Before this age and for bPP×, PD was limited by MEp. In bPP×, the difference between PD and PDmax was small (less than proportionately 0·05). The F did not change with BW for bPP× (2·85 × MEm) whereas for the other genotypes, it decreased linearly from 4·47 at 45 kg to 2·00 at 100 kg of BW. Due to its nature, the model allows estimation of PDmax even when energy is restricting PD.
Nose-rings influence feeding efficiency in pigs
Authors: Horrell I. , A’Ness P. , Edwards S. A. , Riddoch I. 
Published: August 2016

AbstractNose-rings are often fitted to outdoor commercial pigs to inhibit rooting and reduce consequent pasture damage. During ethological observations of the behaviour of ringed pigs at pasture, subjective impressions suggested that pigs with nose-rings picked up their normal feed, in the form of large nuts (‘roll nuts’), more tentatively than unringed pigs. The observed pigs were gestating sows under one of three treatments: unringed controls (UR), multiple wire ‘clip-rings’ through the upper rim of the snout (CR), or rigid ‘bull-rings’ through the nasal septum (BR). For formal assessment of feeding efficiency eight randomly selected pigs from each condition were timed and video-recorded, in individual feeder stalls, as they ate 20 3-cm long roll-nuts laid out in a standard rectilinear array in a steel-sided tray under each of five conditions: on a hard surface, on the surface of soil, on the surface of turf, embedded in soil, or embedded in turf. All groups took longer to eat up their test meal from the plain surface than from the surfaces of either soil or turf and longer still when the nuts were embedded. In all conditions, ringed pigs took longer to eat their 20 nuts than did controls, with BR > CR > UR (overall mean times, pooling data from the different feeding conditions: 118·6, 69·9 and 56·7 s respectively: P < 0·001). The difference between groups was greatest when nuts were embedded. Also, when nuts were embedded, ringed pigs were more reluctant to root: the latency to their first rooting action was delayed (mean latency across both embedded’ conditions: 29·6, 87·9 and 106·8 s for UR, CR and BR pigs, respectively: P < 0·01 with soil and turf conditions combined) and, even after starting, a smaller proportion of the residual trial time was spent rooting (0·11, 0·27 and 0·62 of the total time by BR, CR and UR pigs respectively; P < 0·001). It is concluded that nose-ringing depresses the efficiency with which pigs feed on solid food, especially if they have to root for it. The threat to welfare inherent in this will be greatest when ringed pigs are in direct competition with unringed pigs.
Management factors affecting activity and aggression in dynamic group housing systems with electronic sow feeding: a field trial
Authors: Jensen K. H. , Sørensen L. S. , Bertelsen D. , Pedersen A. R. , Jørgensen E. , Nielsen N. P. , Vestergaard K. S. 
Published: August 2016

AbstractA series of 24-h video studies on four commercial Danish pig herds investigated the behaviour of pregnant sows kept in dynamic groups (72 to 200 sows) with electronic sow feeding (ESF). The herds mainly differed with respect to provision of a layer of unchopped straw as bedding material, the frequency of introduction/removal of animals, space allowance in the lying area, group size and number of feeding stations, and starting times for the feeding cycle. All herds had one feeding cycle per 24 h. Six 24-h video recordings in the most settled period with respect to rank relationships (2 to 12 days after the last introduction) were collected from each herd and analysed according to activity and aggressive interactions. In two of the four herds recordings were collected in two separate periods with different starting times for the feeding cycle. In all herds peaks of activity in the morning and in the afternoon were evident. Furthermore, the diurnal variation was overlaid by an increase in activity at the start of the feeding cycle. The activity and aggression in the feeding area as well as the duration per sow of the period with high feeder occupation were lowest in herds where a layer of straw bedding was provided. Changing feeding start from day time to night time was accompanied by a reduced feeder occupation in the period following start of the feeding cycle. However, in herd 1 (characterized by no litter, high stocking density and high frequency of grouping) the level of aggression was reduced, whereas it was increased in herd 2 (characterized by straw in lying area, low stocking density, low frequency of regrouping). Number of regroupings and space allowance apparently had no obvious effects on the average frequency of aggression or the aggression per sow at risk in periods between introduction of new animals, but space allowance may have improved social function by weakening the association between activity and aggression. Due to the small number of herds included the present results were descriptive rather than conclusive. However, the study supports the suggestions that provision of unchopped straw as bedding material and starting the feeding cycle in the evening for overnight feeding may improve behaviour in dynamic group housing systems with ESF. However, the benefits of starting the feeding cycle in the evening may depend on low disturbance in daytime from other management procedures.
Environmental enrichment of intensive pig housing using spent mushroom compost
Authors: Beattie V. E. , Sneddon I. A. , Walker N. , Weatherup R. N. 
Published: August 2016

AbstractIn a comparative study which examined the effect of having access to mushroom compost in an otherwise barren environment there were three treatments and six replicates. The three treatments were (T1) control barren pen providing 0·7 m2per pig with fully slatted floor, (T2) empty horizontal rack suspended above the pigs’ heads and (T3) mushroom compost on rack as in treatment 2. Pigs released particles of compost from the rack by nosing the metal grid from below. Almost twice as many pigs with access to mushroom compost (T3) nosed the rack (P< 0·001) and the ground below the rack (P< 0·001) as pigs which had a rack with no mushroom compost (T2). Fewer pigs with mushroom compost were involved in behaviours directed at penmates such as nosing, biting and chewing penmates than pigs in treatments 1 and 2 (P< 0·001). In addition fewer pigs in T3 were involved in feeding behaviour than in T1 and T2 (P< 0·05). Percentages of tail-bitten animals which had to be removed were 11 and 24 for T1 and T2 respectively while T3 had < 1% removed because of tail biting (P< 0·05). Apparent food intake was higher (P< 0·05) and food conversion ratio tended to be poorer in T1 (P= 0·1). It is suggested that pigs will redirect rooting behaviour towards penmates and the feeder in the absence of any rooting substrate. Adding substrate to commercial finishing pens reduces this redirection of behaviour and improves welfare by minimizing injury through tail biting.