Antibiotics are designed to affect gut microbiota and subsequently gut homeostasis. However, limited information exists about short- and long-term effects of early antibiotic intervention (EAI) on gut homeostasis (especially for the small intestine) of pigs following antibiotic withdrawal. We investigated the impact of EAI on specific bacterial communities, microbial metabolites and mucosal immune parameters in the small intestine of later-growth-stage pigs fed with diets differing in CP levels. Eighteen litters of piglets were fed creep feed with or without antibiotics from day 7 to day 42. At day 42, pigs within each group were offered a normal- or low-CP diet. Five pigs per group were slaughtered at days 77 and 120. At day 77, EAI increased Enterobacteriaceae counts in the jejunum and ileum and decreased Bifidobacterium counts in the jejunum and ileum (P < 0.05). Moreover, tryptamine, putrescine, secretory immunoglobulin (Ig) A and IgG concentrations in the ileum and interleukin-10 (IL-10) mRNA and protein levels in the jejunum and ileum were decreased in pigs with EAI (P < 0.05). At day 120, EAI only suppressed Clostridium cluster XIVa counts in the jejunum and ileum (P < 0.05). These results suggest that EAI has a short-term effect on specific bacterial communities, amino acid decarboxylation and mucosal immune parameters in the small intestine (particularly in the ileum). At days 77 and 120, feeding a low-CP diet affected Bifidobacterium, Clostridium cluster IV, Clostridium cluster XIVa and Enterobacteriaceae counts in the jejunum or ileum (P < 0.05). Moreover, feeding a low-CP diet increased the concentrations of Igs in the jejunum and decreased pro-inflammatory cytokines levels in the jejunum and ileum (P < 0.05). At day 120, feeding a low-CP diet increased short-chain fatty acid concentrations, reduced ammonia and spermidine concentrations and up-regulated genes related to barrier function in the jejunum and ileum (P < 0.05). These results suggest that feeding a low-CP diet changes specific bacterial communities and intestinal metabolite concentrations and modifies mucosal immune parameters. These findings contribute to our understanding on the duration of the impact of EAI on gut homeostasis and may provide basis data for nutritional modification in young pigs after antibiotic treatment.

The development and moulting of the birth and first adult coat of two genotypes of cashmere-bearing goats, a highyielding Siberian (S) and low-yielding Icelandic × Scottish feral (IF), were examined. Samples of fibre from the neck, mid side, belly and rear-leg areas and of mid-side skin were obtained monthly from five male and five female kids of each genotype from birth to 13 months of age. Guard hair and undercoat length, secondary/primary (S/P) skin follicle ratio and the proportion of skin follicles containing a non-growing fibre with a brush end were recorded. S/P ratio reached an asymptote between 4 and 5 months of age and was higher fP < 0·01) in S (10·7) than in IF (6·7) kids. In both genotypes peaks of brush formation in primary follicles occurred between 2 and 4 months and again between 8 and 11 months of age. In contrast to primary follicles, secondary follicles had only a single peak of brush formation occurring at 10 and 8 months of age for S and IF kids respectively. Guard hair moulted from the birthcoat, but there was no loss of undercoat prior to 12 months of age and harvesting of cashmere prior to this time is unnecessary.

The secondary follicles of S kids had a longer growing period and fibre length increased at a greater rate than that of IF kids, resulting in more than a two-fold difference in the maximum undercoat length. Assessments to estimate the final weight and proportion of cashmere, made prior to completion of growth of the fleece, are likely to underestimate these parameters for high-yielding goats in comparison with their low-yielding counterparts. However, it is unlikely to alter the ranking, and hence the selection, of animals for retention in the breeding herd.

The aim was to determine whether dietary threonine levels affected hepatic insulin-like growth factor-1 (IGF-1) mRNA expression as well as plasma IGF-1 concentration and IGF binding protein (IGFBP) profile in growing pigs. Two male 6-week-old pigs from each of seven litters were used. Each littermate was assigned to one of two diets, control or low threonine (LT), providing per kg 14·3 MJ digestible energy in both diets, 170 g protein in the control diet and 167 g protein in the LT diet. The control diet contained all essential amino acids in the recommended amounts, including 8·2 g threonine per kg. The LT diet was similar but contained only 5·1 g threonine per kg. Pigs were pair-fed these diets for 3 weeks. Growth rate and food efficiency of pigs given the LT diet were significantly lower than those of pigs given the control diet (P 0·001). Plasma IGF-1 concentration of pigs given the LT diet was proportionately 0·44 lower than that of pigs given the control diet (P 0·01). Plasma free threonine concentration of pigs given the LT diet was lower than that of the pigs given the control diet (P 0·001). Plasma IGFBP2 level of pigs given the LT diet was significantly higher than that of pigs given the control diet (P 0·05). Pigs given the LT diet had a significantly lower plasma IGFBP3 level compared with their littermates given the control diet (P 0·05) suggesting that clearance rate of circulating IGF-1 was higher in the LT group. Dietary threonine level did not affect IGF-1 mRNA abundance in the liver. It is concluded that lower plasma IGF-1 level caused by reduced dietary threonine level may have been partly due to increased clearance rate of circulating IGF-1 but not due to IGF-1 gene expression in the liver.

To determine the endogenous contribution of purine derivatives (PD) to renal excretion and the urinary recovery of duodenal purine bases (PB), five dairy Granadina goats (initial weight ± s.e.: 38.6 ± 2.78 kg) were each fitted with a duodenal infusion catheter. Animals were offered ad libitum a mixed diet (75 : 25; alfalfa hay : concentrate), which was supplied in equal portions every 3 h. To label microbial PB, (15NH4)2SO4 was added to the concentrate. The lower enrichment of urinary PD (15N-allantoin) compared with duodenal PB enrichment confirmed the presence of an endogenous PD fraction (268.5 ± 21.98 μmol/kg weight0.75 or 0.386 of the total PD excretion). The recovery of PD in urine and milk increased linearly in response to increasing amounts of duodenally infused RNA (starting on day 21 after parturition). On average, 0.74 of infused PB from RNA was recovered in urine. Milk PD constituted a minor (<0.01) fraction of the total PD excretion and this fraction decreased as the amount of infused PB increased. Our findings indicate that lactation in goats did not affect the urinary recovery of duodenal PB but increased the endogenous contribution to urinary excretion of PD.

In an attempt to establish an ad libitum, labour saving feeding system 12 Large White primiparous sows were used to investigate the effects on food intake and digestibility of including oat husks in a conventional concentrate diet. The diet contained 500 g ground oat husks per kg diet and was compared with the undiluted concentrate given in restricted amounts during pregnancy (1·8 kg/day) and lactation (5·4 kg/day). The mean daily food intakes for the oat husk diet were 5·50 and 6·29 kg during pregnancy and lactation respectively. The apparent digestibility of the dry matter of the oat husk diet (0·58) was significantly lower than that of the concentrate (0·80), but values for apparent digestibility of nitrogen were similar (0·77 and 0·78, respectively).

Changes in the formulation and flavour of concentrate foods may temporarily reduce their acceptability to cattle, leading to reduced intake when they are offered for a limited time during milking. The rate of intake of 12 dairy cows offered 1 kg of salty or bitter concentrates was compared with a sweet concentrate, with or without an artificial sweetener to mask adverse flavours. The cows were offered the test concentrates twice a day in a Latin-square design with seven feeding occasions per period and the apparent and actual (excluding non-feeding time) food intake rates were recorded for all seven feeding occasions. Both apparent and actual intake rates were slower for the bitter compared with the salty and sweet flavoured concentrate.

For the first two feeding occasions the intake rate was recorded separately for the 1st min and the subsequent period until the end of feeding. The intake rate was faster in the 1st min because of more rapid prehension of the food and fewer interruptions to the feeding process. Where no mask was included there was no effect of flavour on the apparent intake rate in the 1st min of the first feeding occasion but in the 1st min of the second feeding occasion the apparent intake rate of the salty concentrate was less than that for the sweet or bitter concentrates. The actual intake rates of the bitter and salty concentrates were less than for the sweet concentrate. The mask increased the apparent intake rate of the bitter and sweet concentrates in the 1st min of both the first and second feeding occasions, by reducing the non-feeding time and it also increased the actual intake rate of salty concentrates.

After the 1st min the apparent intake rate of the salty concentrate was faster than that of the bitter and sweet concentrates, where no mask was included. The mask increased the apparent intake rate of the sweet concentrates at this time but reduced it for salty and bitter concentrates. It therefore reduced the acclimatization to the salty and bitter concentrates and enhanced the attractiveness of the sweet concentrates.

There was a residual effect from the previous period of concentrates which were eaten slowly i.e. salty concentrates, which reduced the 1st min intake of foods that were eaten rapidly, i.e. sweet concentrates, in the subsequent period. This was largely due to increases in the time spent pausing between bouts of food ingestion. After the 1st min the apparent intake rate of cows receiving salty concentrate for a second consecutive period was increased, suggesting acclimatization. The opposite effect was observed for the sweet concentrate, probably because the novelty of the sweetness had diminished, making it relatively less attractive to the cow. This experiment therefore provides evidence that bitter and to some extent salty concentrates are consumed at a slower rate than sweet concentrates, except for the 1st min in which they are offered to cattle and that a reduced concentrate intake rate may persist after the flavour is removed from the food. Cattle did, however, demonstrate an ability to acclimatize to salty concentrate over time.

1. British Friesian male calves were offered, in two experiments, either chopped, or ground and pelleted dried grass diets to appetite. In one experiment the pelleted diet was also given in restricted quantities. The calves were slaughtered without being fasted, 6 to 9 weeks after weaning, and detailed measurements were made of the weights and volumes of the sections of the alimentary tract and its contents, and of other abdominal organs.

2. Grinding and pelleting the diet reduced mean retention time by approximately 50% and digestibility by 6 to 8 units, and increased dry-matter intake in the two experiments by 55 or 32% respectively, and growth rate by 53 and 69% respectively.

3. The ground and pelleted diets resulted in a smaller quantity of fluid digesta in the rumen, and a much greater quantity in the abomasum and small intestine.

4. There were smaller differences between diets in the quantity of digesta in the combined caecum and colon, or in the total volume of the organs of the abdomen, than in the amount of digesta in the rumen. It is suggested that further critical studies are required upon the importance of the contents of the alimentary tract, or of the abdomen as a whole, in the control of voluntary food intake in ruminants.

Effects of open field testing and associated handling (including blood sampling) v. handling (with blood sampling) alone on adrenocortical reactivity were investigated in piglets around weaning. After weaning at day 28, piglets were mixed to form eight replicates with three litter each and kept on slatted floors. Treatments were open field/novel object testing and associated handling (OFT + H) v. handling alone (H) (no. = 40). Testing took place on the following days (weaning day 0): -4, 0, 1, 4 and 8 (no. = 16). The open field/novel object test lasted 10 min and blood was sampled by venipuncture before and after the test and/or handling procedures. In the first blood sample, plasma concentration of cortisol did not differ between OFT + H and H piglets. In the second blood sample, however, OFT + H piglets had a higher concentration of cortisol and a larger increase in cortisol than H piglets (P < 0·01). In the first blood sample the concentration of cortisol was affected by day (P < 0·05), with concentration on day -4 being lower than those on day 0, 1, and 4 and the concentration on day 8 was lower than the concentration on day 0 as well. However, no differences were found between days for the second blood sample nor the adrenocortical reactivity. In conclusion, the increase in pre-treatment cortisol in the first 4 days after weaning as well as the lack of changes in the adrenocortical reactivity after weaning suggest that the temporal development of HPA activity and reactivity in piglets after weaning are comparable with other, more standardized long-term stressors. Exposure to an open field/novel object test and associated handling results in higher adrenocortical reactivity than handling alone but the latter (including blood sampling) in itself accounts for proportionately 0·74 of the cortisol response.

Phenotypic and genetic analyses of the litter traits total number born, number born alive and total birth weight were conducted on data from two lines of pigs, line A, a synthetic largely of Landrace origin, and line B, derived from the Large White breed. The data were collected from closed herds of the Cotswold Pig Development Company Limited and comprised 1018 litters in line A and 863 litters in line B. Estimates of heritability and repeatability were low for all traits and consistent with other estimates in the literature, for number born alive being respectively, 0·07 (s.e. 0·04) and 0·15 (s.e. 0·04) in line A and 0·12 (s.e. 0·04) and 0·14 (s.e. 0·04) in line B. There was no evidence of an effect of the size of litter into which a female was born on her subsequent reproductive performance.

Blood groups were determined for eight loci in a total of 742 sheep and for the Tf (transferrin) locus of 512 sheep comprising the Scottish Blackface, the Cheviot and the Welsh Mountain breeds and their crosses. Each breed and cross was represented by a non-inbred F2 generation and by three stages of inbreeding (25, 37½ and 50%). The loci for which all genotypes were distinguished were Hb, M, and Tf, and those for which partial description (including the recessive homozygote) was made were A, B, C, D, R and i.

There were large differences among the three pure breeds only for the frequencies at the Hb and Tf loci. The homozygote frequencies of the Blackface-Welsh and Cheviot-Welsh crosses were approximately half-way between their respective pure breeds. For the Blackface-Cheviot cross the homozygote frequency was considerably lower than either parental breed, suggesting that over all loci there were greater differences in gene frequencies between these two breeds than between the Blackface and Welsh or Cheviot and Welsh.

On average over all loci (except Tf) inbreeding had the effect of decreasing heterozygosity roughly in relation to expectation. Individually this effect was statistically significant only for ii, MbMb, HbAHbA and HbbHbb. For the Tf locus there was no average decrease in heterozygosity as a result of 25% inbreeding but thereafter there was a greater decrease in the purebreds than in the crosses.

There were small (< 0·20) but significant residual correlations between R-O-ii blood types and genotypes at several other loci, and between dd and the M system genotypes.

Seasonal reproduction is one of the major biotechnical and economic constraints of sheep production in temperate latitudes. Treatments using extra light followed by melatonin implants have been used satisfactorily in open barns, farms and artificial insemination centres to produce out-of-season sexual activity in rams. The aim of the present study is to explore the possibility of replacing melatonin implants with continuous light (LL), which was recently shown to increase LH secretion similar to melatonin and/or pinealectomy. Four experiments during 4 consecutive years were conducted in ‘Ile-de-France’ rams. In each study, one group was systematically exposed to permanent light after a first photoperiodic treatment of 60 long days (LD-LL) during the winter and compared with various other control groups subjected either to a natural photoperiod or the classical LD-melatonin treatment. As expected, blood nocturnal melatonin secretion was suppressed by LL. In all four experiments, LL treatment produced a highly significant and robust increase in ram testicular volume in the spring compared with the testicular volume of control rams or of that of treated rams at the end of the LD. For the two experiments in which fertility was tested, fertility after hand-mating was significantly higher in LD-LL rams than in control rams (76% v. 64%). Therefore, permanent light after an LD treatment may be an interesting alternative to LD-melatonin treatment to induce out-of-season sexual activity in rams.

Finishing late-maturing bulls on grass may alter the antioxidant/prooxidant balance leading to beef with higher susceptibility to lipid oxidation and a lower colour stability compared to bulls finished on cereal concentrates. In this context, lipid oxidation and colour stability of beef from late-maturing bulls finished on pasture, with or without concentrate supplements, or indoors on concentrate was assessed. Charolais or Limousin sired bulls (n = 48) were assigned to four production systems: (1) pasture only (P), (2) pasture plus 25% dietary DM intake as barley-based concentrate (PC25), (3) pasture plus 50% dietary DM intake as barley-based concentrate (PC50) or (4) a barley-based concentrate ration (C). Following slaughter and postmortem ageing, M. Longissimus thoracis et lumborum was subjected to simulated retail display (4°C, 1000 lux for 12 h out of 24 h) for 3, 7, 10 and 14 days in modified atmosphere packs (O2 : CO2; 80 : 20). Lipid oxidation was determined using the 2-thiobarbituric acid-reactive substances assay; α-tocopherol was determined by HPLC; fatty acid methyl esters were determined using Gas Chromatography. Using a randomised complete block design, treatment means were compared by either ANOVA or repeated measures ANOVA using the MIXED procedure of SAS. Total polyunsaturated fatty acid (PUFA) concentrations were not affected by treatment, n-3 PUFAs were higher (P < 0.001) and the ratio of n-6 to n-3 PUFAs was lower (P < 0.001) in muscle from P, PC25 and PC50 compared to C. α-Tocopherol concentration was higher in muscle from P compared to PC50 and C bulls (P = 0.001) and decreased (P < 0.001) in all samples by day 14. Lipid oxidation was higher in muscle from C compared to P bulls on day 10 and day 14 of storage (P < 0.01). Finishing on pasture without supplementation did not affect beef colour stability and led to lower lipid oxidation, possibly due to the higher α-tocopherol concentration compared to concentrate finished beef.

This study was conducted to evaluate the effect of increasing levels of glycerol in the diet on milk yield and composition, diet digestibility and some blood metabolites of dairy buffaloes in early lactation. A total of 24 buffaloes were blocked by average milk yield, parity and BW and then randomly assigned to three treatments: control without glycerol (CON); low glycerol (LG): control plus glycerol at 150 ml/day per buffalo; and high glycerol (HG): control plus glycerol at 300 ml/day per buffalo. The experimental period lasted for 60 days. Feeding LG and HG decreased (P<0.0001) dry matter intake compared with the CON. Buffaloes supplemented with LG and HG produced more milk (P<0.01) and had a greater (P<0.0001) yield of fat-corrected milk (3.5%) than those buffaloes fed control treatment. Glycerol-supplemented buffaloes showed a positive energy status indicated by reduced concentrations of non-esterified fatty acids and β-hydroxybutyrate. Feeding LG and HG tended to increase (P⩽0.10) concentrations of milk fat, and serum total protein and globulin and significantly decreased (P⩽0.05) milk urea nitrogen and somatic cells counts (SCCs) compared to the CON group. Inclusion of LG and HG had no effect on organic matter and non-fiber carbohydrate digestion, but improved dry matter (P=0.02), CP (P=0.09), ether extract (P=0.03), NDF (P=0.07) and ADF (P=0.03) digestion.

In this study, we investigate the extent to which the incidence of Escherichia coli O157:H7 can be predicted in human faeces, from human intake and infection via water contaminated by livestock and carrying this zoonotic pathogen in North-East (NE) and South-West (SW) regions of Scotland. In SW Scotland, there is a risk of coastal recreational waters failing EU standards for faecal indicator organisms, and this is assumed to be the main potential waterborne route of infection. In NE Scotland, the main waterborne route is assumed to be the many private drinking water supplies; these are mainly derived from shallow groundwater and surveys show that there is potential for significant levels of microbial contamination from livestock. The risk to human health from these sources has been assessed using a combination of process models, epidemiological risk-assessment methods and survey data. A key assumption in the calculations is the amount of mixing of pathogenic and non-pathogenic E. coli between animal faecal sources and contaminated water intake by humans. Using the probability distributions of the E. coli O157 content of individual faecal pat material (which would imply no mixing between source and human intake), based on three recent surveys of animal faeces in Scotland, led to predicted annual risks of infection slightly higher than observed human infection incidence. Using the geometric mean to represent partial mixing (which theoretically may over- or underestimate incidence with a concave dose–response curve) gave infection rates similar to those observed for two of the three faecal surveys. Using the arithmetic mean led to over-prediction of risk. This is to be expected if the true dose–response curve is (such as the Beta-Poisson curve used here) concave. Other factors that may lead to over-prediction of incidence are discussed, including under-reporting, loss of infectivity as a result of environmental exposure, immunity and the appropriateness of the Beta-Poisson curve. It is concluded that better epidemiological data for calibration of the dose–response curve, better knowledge of the degree of mixing and understanding of immunity are key requirements for progress in process model-based predictions of infection rate. The paper also explores the potential of improved farm and catchment scale management to deliver cost-effective mitigation of pollution of bathing and drinking water by livestock zoonoses.

The milk production of three groups of cows grazing on veld and receiving different amounts of concentrates during winter and the first 8 weeks of lactation was studied over four successive calving seasons. Calves were weaned at either 150 or 240 days.

Cows offered most concentrates and those whose calves had been weaned early in the previous year produced more milk per lactation (P < 0·01) than other cows but weaning age did not affect yield/cow per year. Data for each treatment in each year were considered as a separate class. Regression analyses showed that milk yield increased with cow weight at calving and with calf birth weight. Changes in cow weight during early lactation, after adjusting for initial weight, were directly related to milk yield.

In a concurrent experiment, three groups of heifers were confined in pens and given sufficient amounts of a complete diet to promote either gain, maintenance or loss of weight during lactation. Heifers that gained or maintained weight produced significantly (P<0·01) more milk of a higher solids-not-fat and protein content than those which lost weight. Food intake had a significant (P < 0·01) positive effect on milk yield but the effects of weight and weight change on milk yield were negative after adjusting for food consumption.

The Spanish local beef cattle breeds have most likely common origin followed by a process of differentiation. This particular historical evolution has most probably left detectable signatures in the genome. The objective of this study was to identify genomic regions associated with differentiation processes in seven Spanish autochthonous populations (Asturiana de los Valles (AV), Avileña-Negra Ibérica (ANI), Bruna dels Pirineus (BP), Morucha (Mo), Pirenaica (Pi), Retinta (Re) and Rubia Gallega (RG)). The BovineHD 777K BeadChip was used on 342 individuals (AV, n=50; ANI, n=48; BP, n=50; Mo, n=50; Pi, n=48; Re, n=48; RG, n=48) chosen to be as unrelated as possible. We calculated the fixation index (FST) and performed a Bayesian analysis named SelEstim. The output of both procedures was very similar, although the Bayesian analysis provided a richer inference and allowed us to calculate significance thresholds by generating a pseudo-observed data set from the estimated posterior distributions. We identified a very large number of genomic regions, but when a very restrictive significance threshold was applied these regions were reduced to only 10. Among them, four regions can be highlighted because they comprised a large number of single nucleotide polymorphisms and showed extremely high signals (Kullback–Leiber divergence (KLD)>6). They are located in BTA 2 (5 575 950 to 10 152 228 base pairs (bp)), BTA 5 (17 596 734 to 18 850 702 bp), BTA 6 (37 853 912 to 39 441 548 bp) and BTA 18 (13 345 515 to 15 243 838 bp) and harbor, among others, the MSTN (Myostatin), KIT-LG (KIT Ligand), LAP3 (leucine aminopeptidase 3), NAPCG (non-SMC condensing I complex, subunit G), LCORL (ligand dependent nuclear receptor corepressor-like) and MC1R (Melanocortin 1 receptor) genes. Knowledge on these genomic regions allows to identify potential targets of recent selection and helps to define potential candidate genes associated with traits of interest, such as coat color, muscle development, fertility, growth, carcass and immunological response.

The expected higher global demand for animal proteins and the competition for starch and sugars between food, fuel and feed seem to favour herbivores that convert solar energy captured in fibrous plants into animal products. However, the required higher production level of herbivores questions the sustainability of this conversion. An increase in herbivore production can be achieved by increasing the number of animals associated with the increasing demand of plant biomass or by improving the efficiency with which plant biomass is converted into meat and milk. The potential to increase food production by cattle, the main food-producing herbivore in the temperate zones outside China, was considered in three production systems: grassland-based, mixed rain-fed and mixed irrigated systems. The potential to increase plant biomass production in grassland-based systems seems limited, unless fertiliser is imported in large quantities and crop production is increased, sacrificing valuable, high-quality grasslands, which often conflicts with sustainable production methods. Also, in mixed systems with high inputs of fertiliser or water, improvements in plant biomass production seem marginal and the main challenges for these systems are in breeding high-quality plant biomass at lower levels of fertiliser and the use of new co-products from food processing and bio-based economies. Consequently, the main challenge in herbivore nutrition management is to improve the efficiency of plant biomass utilisation. Stocking rate management along with seasonal variation in the grazing capacity of grasslands and moderate use of fertiliser may increase meat production in grassland-based systems by 400%. Improving plant biomass utilisation in the more industrialised mixed rain-fed systems seems possible by better feed storage technologies and for dairy cattle by improving animal health and lifetime production level. Managing the transition period seems crucial to achieve more sustainable mixed rain-fed and mixed irrigated dairy production systems. Whether sustainable production methods will be implemented also depends on macro-economic conditions and awareness of regional and global environmental concerns.

Muscle fiber characteristics comprise a set of complex traits that influence the meat quality and lean meat production of livestock. However, the genetic and biological mechanisms regulating muscle fiber characteristics are largely unknown in pigs. Based on a genome-wide association study (GWAS) performed on 421 Large White × Min pig F2 individuals presenting well-characterized phenotypes, this work aimed to detect genome variations and candidate genes for five muscle fiber characteristics: percentage of type I fibers (FIB1P), percentage of type IIA fibers (FIB2AP), percentage of type IIB fibers (FIB2BP), diameter of muscle fibers (DIAMF) and number of muscle fibers per unit area (NUMMF). The GWAS used the Illumina Porcine SNP60K genotypic data, which were analyzed by a mixed model. Seven and 10 single nucleotide polymorphisms (SNPs) were significantly associated with DIAMF and NUMMF, respectively (P < 1.10E-06); no SNP was significantly associated with FIB1P, FIB2AP or FIB2B. For DIAMF, the significant SNPs on chromosome 4 were located in the previously reported quantitative trait loci (QTL) interval. Because the significant SNPs on chromosome 6 were not mapped in the previously reported QTL interval, a putative novel QTL was suggested for this locus. None of the previously reported QTL intervals on chromosomes 6 and 14 harbored significant SNPs for NUMMF; thus, new potential QTLs on these two chromosomes are suggested in the present work. The most significant SNPs associated with DIAMF (ALGA0025682) and NUMMF (MARC0046984) explained 12.02% and 11.59% of the phenotypic variation of these traits, respectively. In addition, both SNPs were validated as associated with DIAMF and NUMMF in Beijing Black pigs (P < 0.01). Some candidate genes or non-coding RNAs, such as solute carrier family 44 member 5 and miR-124a-1 for DIAMF, and coiled-coil serine rich protein 2 for NUMMF, were identified based on their close location to the significant SNPs. This study revealed some genome-wide association variants for muscle fiber characteristics, and it provides valuable information to discover the genetic mechanisms controlling these traits in pigs.

Commercial carcass grading measurements and sample joint dissection were evaluated as predictors of carcass lean concentration using a data set of 1320 pig carcasses from four breeding companies. Entire males, castrated males and gilts from White-type and Meat-type populations were reared on ad libitum or restricted feeding regimens and slaughtered to achieve a carcass weight of either 52·5 kg or 72·5 kg. A model was fitted which examined the accuracy and stability of regression equations for different populations, sexes and feeding regimens, and different values of P2 and carcass weight. The regression slope of lean concentration on P2 differed by sex and population. Lean concentration decreased faster with increases in P2 among gilts than among entire or castrated males. At the same level of P2 and carcass weight, pigs fed ad libitum contained 5 g/kg less lean in the carcass than pigs fed at a restricted level. Biases among populations, sexes and feeding regimens were also found when carcass lean concentration was predicted from additional measurements: muscle depth at P2, fat thickness and muscle depth at 3/4 last ribs, and eye-muscle area. The regression slope of lean concentration on sample joints showed little evidence of variation among populations (except for the hand joint), sexes or feeding regimens. There were important differences in the intercept for different populations. The ham was the most accurate (residual s.d. = 11 g/kg) and least biased joint.

Fifty-one cattle were allocated into five groups varying in time of starvation (0, 17, 24, 41 and 48 h). Most of the loss in fasted live weight, stomach and intestinal contents occurred within 24 h. Weights of water, dry matter and potassium present in the stomach showed a significant decrease in the first 24 h, although the percentage of water in the stomach contents rose slowly over a 48-h period. It is suggested that cattle from pasture need be starved for no more than 24 h to minimize the effect of gut fill for body composition studies.