A total of 9360 offspring of 12 purebred Duroc sires and 692 Landrace × Yorkshire sows were evaluated for six osteochondrosis traits in the left elbow joints at slaughter. Osteochondrosis traits, growth pre- and post weaning, and meat content at slaughter were analysed simultaneously by a multivariate genetic model. Castrates scored worse than female pigs for nearly all osteochondral traits. Heritability of elbow osteochondrosis was moderate (0·02 to 0·28) and, thus, selection against the disorder is possible. Phenotypic correlations among joint surface abnormalities, cartilage thickness, subchondral lesions and cracks in the cartilage at the osteochondral junction in the medial condyle ranged from 0·33 to 0·69, whereas genetic correlations ranged from 0·75 to 0·97. Phenotypic correlations of the sagittal central groove with other abnormalities in the medial condyle were low and insignificant but genetic correlations were strongly significant (0·66 to 0·77). Depression of the proximal edge of the radius was to some extent phenotypically correlated to abnormalities in the medial humeral condyle (around 0·2), while genetic correlations ranged from 0·05 to 0·52. Significant genetic correlations among osteochondral traits indicate that all are part of the osteochondrosis complex. Abnormalities in the joint surface showed the strongest genetic correlations with other osteochondrosis variables in the elbow joint and were moderately inherited (h2 = 0·22), which indicates that this trait can be used as a marker to select against osteochondrosis. Osteochondral traits had no significant genetic correlations with growth to weaning and to 30 kg, slight negative (favourable) genetic correlations with growth from 30 to 100 kg, and slightly positive (unfavourable) genetic correlations with meat content in carcass.

In this study the potential association of PrP genotypes with meat traits has been investigated. The data included young rams from individual testing stations of three breeds: Ile de France, Préalpes du Sud and Blanc du Massif Central. These breeds were chosen due to their large number of available animals (with performance records and PrP genotypes) and their differential ARR haplotype frequency. Two analyses differing in the PrP genotype classes considered were carried out. Firstly, animals were categorized into three classes: ARR homozygous, ARR heterozygous, and animals without the ARR haplotype. The data for this analysis included 725, 534 and 832 animals for Ile de France, Préalpes du Sud and Blanc du Massif Central breeds, respectively. Secondly, as the two predominant haplotypes in these breeds are ARR and AR- (and AR- includes ARQ and ARH haplotypes), the effect of substituting 1 or 2 ARR haplotypes for AR- haplotypes was studied. These comparisons involved three genotype classes: ARR homozygous, ARR/AR-, and AR-homozygous. The data for this analysis included 532, 509 and 620 animals of Ile de France, Préalpes du Sud and Blanc du Massif Central breeds, respectively. Meat traits were analysed using an animal model (where the PrP genotype was included as a fixed effect) and they included growth rate, ultrasonic fat depth, and ultrasonic muscle depth. The results of this study indicate no evidence of association between PrP genotypes and the meat traits studied in these sheep breeds.

Data obtained from a detailed base from a commercial breeding company of Landrace and Large White purebred nucleus sows were used to estimate genetic parameters of piglet number born alive (NBA) following artificial insemination and natural service. Heritabilities were small but significantly different from zero, and similar to literature estimates. The genetic correlation (rG) of NBA after AI or natural service using pooled data was 0·71 and was significantly different from one (P<0·01) but not significantly different between breeds (P>0·1). It is concluded that mating type may result in a re-ranking of sow genetic merit for NBA.

Multivariate restricted maximum likelihood analyses were carried out for a large data set comprising records for eye-muscle area, fat depth at the 12/13th rib and the rump P8 site, and percentage intramuscular fat, recorded via live ultrasound scanning of Australian Angus cattle. Records on heifers or steers were treated as separate traits from those on bulls. Reduced rank estimates of the genetic covariance matrix were obtained by restricted maximum likelihood, estimating the leading three, four, five, six, seven and all eight principal components and these were contrasted with estimates from pooled bivariate analyses.

Results from analyses fitting five or six genetic principal components agreed closely with estimates from bivariate and eight-variate analyses and literature results. Heritabilities and variances for ‘fatness’ traits measured on heifers or steers were higher than those recorded for bulls, and genetic correlations were less than unity for the same trait measured in different sexes. Eye-muscle area showed little association with the other traits.

Reduced rank estimation decreased computational requirements of multivariate analyses dramatically, in essence corresponding to those of an m-variate analysis for m principal components considered. Five or six principal components appeared to be necessary to model genetic covariances adequately. The first three of these components then explained about 97% of the genetic variation among the eight traits.

A simulation study showed that errors in reduced rank estimates of the genetic covariance matrix were small, once three or more principal components from analyses fitting five or more components were used in constructing the estimates. Similarly, accuracy of genetic evaluation for the eight traits using the first four components was only slightly less than that using all principal components.

Results suggest that reduced rank estimation and prediction is applicable for the eight scan traits considered. The leading three to four principal components sufficed to describe the bulk of genetic variation between animals. However, five or more principal components needed to be considered in estimating covariance matrices and the ‘loadings’ of the original traits to the principal components.

Two experiments were conducted to investigate the use of dietary manipulation as a means of improving piglet post-weaning performance and gastro-intestinal health. In experiment 1, 144 piglets (24 days old) in a 3 × 2 factorial arrangement were offered diets containing 65, 170 and 280 g lactose per kg with or without lactic acid (16 g/kg) for 28 days. In experiment 2, 20 piglets (24 days old) (in a 2 × 2 factorial arrangement were offered the following diets for 7 days and then sacrificed: T1) basal diet; T2) basal diet + 15 g inulin per kg; T3) basal diet + 16 g lactic acid per kg and T4) basal diet + 15 g inulin per kg + 16 g lactic acid per kg. After slaughtering, tissue samples were taken from the duodenum, jejunum and ileum for morphological measurements. Digesta samples were taken from the ileum, caecum and colon for microbiology and volatile fatty acid analysis. In experiment 1, pigs offered diets containing lactic acid had improved daily gain (P < 0·01) and food efficiency (P < 0·05) from days 0 to 7 compared with pigs offered diets containing no lactic acid. There was a linear increase (P < 0·05) in average daily gain (ADG) from days 0 to 28 and a linear decrease in faecal pH (P < 0·01) with increasing lactose levels. There was a quadratic effect of lactose on food conversion ratio from days 0 to 28 (P < 0·05). In experiment 2, there was a significant interaction between inulin and lactic acid in villous height in the jejunum (P < 0·001) and the concentrations of lactobacilli (P < 0·1) and E. coli (P < 0·05) in the colon. The inclusion of inulin and lactic acid resulted in a significant increase in villous height compared with the inulin only diet (P < 0·001). However, lactic acid had no effect on villous height in pigs offered diets without inulin supplementation. The inclusion of lactic acid and inulin caused a significant increase in both lactobacilli and E. coli concentrations compared with the inulin only diets (P < 0·05). However, neither inulin nor lactic acid had an effect on lactobacilli and E. coli numbers in isolation of the other. In conclusion, in experiment 1, lactic acid improved performance in the 1st week post weaning. There was a linear increase in ADG with increasing lactose levels. In experiment 2, the combination of lactic acid and inulin increased villous height in the jejunum and concentrations of lactobacilli and E. coli in the colon.

A 2 × 2 factorial experiment was conducted to investigate the interaction between cereal type (wheat v. barley) and an exogenous enzyme supplement (with or without) on nutrient digestibility, large intestinal microflora, volatile fatty acid profile and in vitro manure ammonia emissions from finisher pigs. The enzyme supplement used contained endo-1, 3-β-glucanase (EC 3·2·1·6) and endo-1, 4-β-xylanase (EC 3·2·1·8). The diets were formulated to contain similar concentrations of net energy (9·8 MJ/kg) and lysine (10·0 g/kg). Urine and faeces were collected over seven consecutive days from 16 boars (four boars per treatment, 80·0 kg live weight) that were housed in metabolism crates. After collections, the pigs were slaughtered and the contents of the intestinal tracts were removed for analysis. There was a significant interaction between cereal type and enzyme inclusion in the apparent total tract digestibility of dry matter (DMD), organic matter (OMD) and nitrogen. The inclusion of an enzyme supplement in barley-based diets increased (P < 0·05) DMD, OMD and nitrogen digestibility compared with unsupplemented diets, however there was no effect of enzyme supplementation in wheat-based diets. There was a significant interaction between cereal type and enzyme inclusion in selected components of the gut microflora. Pigs offered unsupplemented barley-based diets had higher populations of bifidobacteria (P < 0·05) in the caecum and colon than those on the enzyme supplemented barley diet, however, there was no effect of enzyme supplementation on bifidobacteria in wheat-based diets. There was a significant interaction between cereal type and enzyme inclusion in volatile fatty acid production and in in vitro ammonia emissions. In the absence of an enzyme supplement, barley-based diets reduced the proportion of isovaleric acid (P < 0·05) and isobutyric acid (P < 0·05) in the caecum and colon and also reduced manure ammonia emissions during storage from 0 to 240 h (P < 0·05) compared with the wheat-based diet, however there was no effect of cereal type in enzyme-supplemented diets. In conclusion, the inclusion of an enzyme in barley-based diets increased nutrient digestibility but also increased ammonia emissions.

The effects of an Aspergillus oryzae extract containing alpha-amylase activity (Amaize™, Alltech Inc., Nicholasville, KY) were examined in vivo and in vitro. A lactating cow study employed 20 intact and four ruminally fistulated Holstein cows in a replicated 4 × 4 Latin-square design to examine the effects of four concentrations of dietary Amaize™ extract on milk production and composition, ruminal fermentation and serum metabolite concentrations. The treatment diets contained 0, 240, 480 or 720 alpha-amylase dextrinizing units (DU) per kg of total mixed ration (TMR) (dry-matter basis). The supplemental alpha-amylase increased the yields of milk (P = 0·02), fat (P = 0·02) and protein (P = 0·06) quadratically. The maximum milk yield was obtained when 240 DU per kg of TMR were offered. Ruminal in situ starch disappearance was not affected by alpha-amylase supplementation in lactating cows or ruminally cannulated steers. Supplemental alpha-amylase extract reduced the molar proportion of propionate in the rumen of steers (P = 0·08) and lactating cows (P = 0·04), and in rumen-simulating cultures (P = 0·04). The supplement also increased the molar proportions of acetate (P = 0·06) and butyrate (P = 0·05), and the serum beta-hydroxybutyrate (P = 0·01) and non-esterified fatty acid (P = 0·03) concentrations in lactating cows. The improvements in milk production appear to be a consequence of the effects of alpha-amylase on ruminal fermentation and the potential changes in nutrient metabolism that result from them. We conclude that supplemental alpha-amylase may be given to modify ruminal fermentation and improve milk and component yield in lactating Holstein cattle.

The effects of 1-h soaking of a pig diet based on wheat and barley with low (4·1 g P per kg) and high (6·8 g P per kg) total phosphorus (P) content on total tract apparent digestibility and performance in growing-finishing pigs were studied in a balance and a performance trial respectively. Phosphorus bound to inositol penta- and hexaphosphate (IP5-IP6) was reduced by proportionately 0·1 in the soaked food. Soaking numerically increased the apparent digestibility of P. The digestibility of P did not differ between the dry high P and the soaked low P. Excretion of P in urine was correlated (R2 = 0·84) with the intake of digestible P. The average daily weight gain, final body weight and carcass weight were lower (P < 0·001), and the energy conversion ratio was higher (P < 0·001) in the dry low P treatment than in the other treatments. Pigs on the low P diets had lower levels of inorganic P in serum (P < 0·01) and slightly higher serum Ca values (P < 0·05) and there were no effects of soaking. The density of femur was lower (P < 0·01) in both the low P treatments than in the high P treatments, and soaking of the low P diet improved (P < 0·01) femur density. In conclusion, a 1-h soaking of pig food in water appears to be sufficient to improve P availability and growth performance.

A photogrammetric stereo imaging system was used to capture 3-D models of live pigs, and quantitative shape measurements were extracted from cross sections of the models. Stereo images were captured of 32 pigs, divided into high-lysine and low-lysine diet groups, and 3-D models were built from the images. Each pig was imaged once per week for 14 weeks. After slaughter, 10 of the pigs were dissected for muscle and fat measurements. A sequence of algorithms was applied to the 3-D models: differential geometry to reveal surface curvature features and detect the spine; manual landmark placement; fitting a curve to the spine; determining the vertical axis of the body; placing a slice plane across the abdomen close to the P2 position; extracting a cross section; and fitting a shape model to the cross section. Differential geometry revealed many qualitative features of the musculature. The spine was a line of minimum curvature along the back. The high-lysine pigs had higher height-to-width ratios and flatter backs than the low-lysine pigs. The dissected total muscle mass had a -0·66 correlation with the flatness-of-back shape parameter, and a 0·64 correlation with weight.

Carrying multiple foetuses leads to a decline in lamb birth weight. The rate of litter size-dependent birth weight decline (LSDBD) in a population can be obtained by calculating the linear relationship between the reciprocal of lamb's birth weight and the respective litter size. Based on published data on lamb birth weight and by using the reciprocal approach, LSDBD rate was calculated for 70 purebred and crossbred sheep populations in which birth weight of lambs born as singles ranged from 1·3 to 6·3 kg. High variability in LSDBD was found. Both genetic and environmental factors may contribute to the variability of this trait.

Plasma cortisol concentrations were determined from the blood of eight mature female reindeer (Rangifer tarandus tarandus) after an intravenous injection of either saline (control) or 100, 250 or 500 μg of synthetic ACTH. Blood samples were collected at 0, 2, 4, 6, 8, 10, 15, 20, 25, 30, 45, 60, 75, 90, 120, 150, and 180 min after the injections. The aims were to determine the appropriate dose of ACTH for adrenal stimulation tests, to define the dose level of ACTH which elicited a maximal cortisol response and to describe the range of blood cortisol concentrations for reference when evaluating the stress responses of reindeer.

The mean plasma cortisol concentrations (s.e.) at the zero sample times (t0) of the control and the ACTH treatments varied between 93·4 (11·8) and 132·5 (18·1) nmol/l. The total plasma cortisol response (area under curve, AUC, nmol/l × min) increased with increasing dose of ACTH (P < 0·001). The AUC of the control treatment was significantly smaller than of the ACTH treatments (P < 0·001). The highest dose of ACTH (500 μg) gave a significantly bigger AUC than the lowest dose (100 μg) (P = 0·008). The maximal plasma cortisol concentrations (CMAX) were achieved within 60 min of the ACTH injections. The ranges of individual CMAX were 59·0 to 136·8 nmol/l for the control treatment, and 110·0 to 252·0, 152·0 to 247·5 and 135·1 to 257·1 nmol/l for 100, 250 and 500 μg ACTH, respectively. The difference in CMAX was significant between the control treatment and the ACTH treatments (P < 0·001) but not between the different doses of ACTH. The plasma cortisol concentrations at the end of the observation period at t180 were not significantly affected by the ACTH treatment (P > 0·05).

In conclusion, the 100-μg dose of ACTH was sufficient to produce a significant cortisol response compared with the control treatment. Increasing the dose did not increase the maximal response, but tended to elongate the response profile. The blood sampling frequency used in the study was found suitable for detection of the cortisol response in reindeer.

Fall-calving multiparous Angus × Hereford cows 3 to 10 years of age were stratified by age in a three by two factorial treatment arrangement to evaluate the efficacy of modifying stocking rate and supplementation strategy to manage cow body condition and production parameters over a 5-year study. Efficacy was evaluated quarterly in association with calving, breeding, weaning, and mid way between weaning and calving (i.e. in August). Three protein supplementation strategies (none, standard, strategic) were imposed across both a moderate (0·3 cows per ha) and a high (0·4 cows per ha) stocking rate. In the strategically supplemented group, protein supplement was provided to cows with a body condition score <5·5 at the quarterly evaluations. There was an effect of supplementation on pregnancy rate, which in combination with previously established culling practices resulted in different age profiles amongst supplementation strategies in years 2 to 5 (P < 0·01). Two statistical analyses were therefore conducted to dissociate the confounding effects of supplementation strategy and age. One model included the effect of stocking rate, supplementation strategy, production year, and all interactions; the second included the addition of age and its interactive effects. Stocking rate and supplementation strategy affected pregnancy rate in each of the models (P = 0·003 and P = 0·10, respectively). Standard, non-supplemented and strategically supplemented animals had estimated pregnancy rates of 0·83, 0·76, and 0·79, respectively (P = 0·10). The effects of nutrition on both calving interval and birth weight were independent of the model employed. Animals that were not supplemented had extended calving intervals (P = 0·06), but there was no effect of stocking rate (P > 0·10). Birth weight was not affected by supplementation strategy or stocking rate (P > 0·10). The lower 205-day weights of calves on a heavy compared with moderate stocking rate was independent of age (P = 0·02). However, the increased 205-day weight of calves born to strategically supplemented cows compared with those born to unsupplemented cows was only evident when data were not corrected for differences in age among groups (P = 0·03). Likewise, analyses of cow condition parameters using models without and with age resulted in different interpretations. These results suggest that strategic and standard supplementation result in similar animal performance and that the improvement in herd productivity associated with altering stocking rate and supplementation may partially be due to altered herd age dynamics.

Two experiments were undertaken to investigate the effect of herbage allowance and concentrate food level offered to twin-bearing ewes in the last 6 weeks of pregnancy on ewe and lamb performance. In each study, 96 twin-bearing Greyface (Border Leicester × Scottish Blackface), Rouge × Greyface and Texel × Greyface ewes were used. In experiment 1, the ewes were allocated to eight treatments consisting of two herbage allowances (1·3 and 2·6 kg herbage dry matter per ewe per day) and four concentrate food levels ranging from zero to 1000 g per day. In experiment 2, ewes were offered four herbage allowances (1·3, 1·75, 2·2 and 2·6 kg herbage dry matter per ewe per day) and zero or 500 g concentrates per day. In experiment 1, herbage allowance and concentrate food level had no significant effect on lamb birth weight, lamb mortality or lamb performance up to weaning. Herbage dry matter intake decreased linearly with increasing concentrate food level with a substitution rate of 18 g of herbage dry matter per 100 g concentrate food level. In experiment 2, lamb birth weight increased with increasing herbage allowance (P < 0·01) and with increasing concentrate food level (P < 0·01). However, lamb performance to weaning was unaffected by late pregnancy nutrition. The satisfactory levels of performance obtained with ewes offered grass-only diets in late pregnancy indicates that grazed grass is a high nutritive value food for twin-bearing ewes in late pregnancy.

Finishing bulls need increasingly large cubicles throughout their growth, and optimal cubicle dimensions may differ from those used for dairy cows. The space requirements of finishing bulls was investigated by observing standing-up and lying-down behaviour, lying duration and number of lying bouts, as well as the cleanliness of cubicles and animals before and after increasing cubicle size at four different points in time. Lying area in the cubicles measured 120 × 70 cm at the start and 185 × 110 cm at the end of the finishing period (approx. at 160 and 550 kg, respectively). Twenty animals kept in four groups were observed at weights of approximately 220, 330, 380 and 500 kg before and after cubicle dimensions were increased. The proportion of standing-up events with more than one head lunge decreased with enlargement of the cubicles (P = 0·01). As cubicle size increased, bulls hit the partition rails less on standing up, except at 220 kg weight where the pattern was inverted (interaction: P = 0·001). Partitions were also hit less on lying down as cubicle size increased, except at 220 kg weight with an inverse pattern (interaction: P = 0·01). The number of exploratory head sweeps before lying down did not change with cubicle enlargement (P > 0·5). Bulls slipped more often with cubicle enlargement, except at 380 kg where the difference was inverted (interaction: P = 0·03). They never fell and never turned around in the cubicles. In general, both animals and cubicles were very clean. On average, lying duration decreased (P < 0·01) while the number of lying bouts tended to increase (P = 0·052) with enlargement of the cubicles but the absolute differences were small. Consequently at each point in time, the smaller cubicles still seemed to provide sufficient lying space for the bulls. If the impacts with the partitions were minor and did not represent a serious welfare concern, as suggested by qualitative observations, the cubicle dimensions used could be considered suitable for housing the type of finishing bulls used in this study.

Twenty pregnant Comisana ewes were divided into two groups of 10. One group was allowed to graze a vetch pasture (grass). The second group of animals was housed collectively in a pen and was given hay and concentrates (concentrate). After lambing, all the ewes were allowed to stay with the respective lambs between 18:00 h and 07:00 h of the following day in two different pens. Therefore all the lambs were raised exclusively on maternal milk. The lambs were slaughtered at 38 days of age. Milk and lamb meat (longissimus dorsi muscle) fatty acids were analysed. Ewes on grass produced milk with a lower (P < 0·001) proportion of saturated fatty acids and with a higher proportion of both monounsaturated (P < 0·05) and polyunsaturated fatty acids (P < 0·01) than ewes given concentrates. Trans-vaccenic acid was significantly higher (P < 0·001) in milk from grass-fed animals compared with ewes given concentrates. Linoleic acid (C18: 2 n-6) tended to be higher (P = 0·06) in milk from ewes on concentrates while linolenic acid (C18: 3 n-3) was significantly higher (P < 0·001) in milk from animals grazing pasture. Conjugated linoleic acid (cis-9, trans-11 C18: 2) was almost double in milk from grass-fed ewes compared with animals given concentrates (P < 0·001). Regarding lamb tissue, trans-vaccenic acid (C18: 1 trans-11) was higher (P = 0·01) in the fat from lambs raised by grazing ewes. Linoleic acid (C18: 2 n-6) was at higher concentration (P < 0·001) in the fat from lambs raised by ewes given concentrates. Linolenic acid (C18: 3 n-3) was increased three-fold (P < 0·001) in the fat of lambs from the grass group compared with lambs suckled by ewes given concentrates. The isomer cis-9, trans-11 of conjugated linoleic acid was present at double concentration (P < 0·001) in the fat from animals raised by grazing ewes. Eicosapentaenoic (C20: 5 n-3; EPA) and docosaesaenoic (C22: 6 n-3; DHA) acids were higher (respectively P < 0·001 and P = 0·01) in the intramuscular fat from lambs from the grass group compared with animals from the concentrate group. The n-6/n-3 ratio was lower (P < 0·001) in the meat from lambs raised by grazing ewes. Overall this trial showed that ewe feeding system strongly affects intramuscular fatty acids even in lambs raised exclusively on maternal milk.