Accurate genomic analyses are predicated on access to a large quantity of accurately genotyped and phenotyped animals. Because the cost of genotyping is often less than the cost of phenotyping, interest is increasing in generating genotypes for phenotyped animals. In some instances this may imply the requirement to genotype older animals with greater phenotypic information content. Biological material for these older informative animals may, however, no longer exist. The objective of the present study was to quantify the ability to impute 11 129 single nucleotide polymorphism (SNP) genotypes of non-genotyped animals (in this instance sires) from the genotypes of their progeny with or without including the genotypes of the progenys’ dams (i.e. mates of the sire to be imputed). The impact on the accuracy of genotype imputation by including more progeny (and their dams’) genotypes in the imputation reference population was also quantified. When genotypes of the dams were not available, genotypes of 41 sires with at least 15 genotyped progeny were used for the imputation; when genotypes of the dams were available, genotypes of 21 sires with at least 10 genotyped progeny were used for the imputation. Imputation was undertaken exploiting family and population level information. The mean and variability in the proportion of genotypes per individual that could not be imputed reduced as the number of progeny genotypes used per individual increased. Little improvement in the proportion of genotypes that could not be imputed was achieved once genotypes of seven progeny and their dams were used or genotypes of 11 progeny without their respective dam’s genotypes were used. Mean imputation accuracy per individual (depicted by both concordance rates and correlation between true and imputed) increased with increasing progeny group size. Moreover, the range in mean imputation accuracy per individual reduced as more progeny genotypes were used in the imputation. If the genotype of the mate of the sire was also used, high accuracy of imputation (mean genotype concordance rate per individual of 0.988), with little additional benefit thereafter, was achieved with seven genotyped progeny. In the absence of genotypes on the dam, similar imputation accuracy could not be achieved even using genotypes on up to 15 progeny. Results therefore suggest, at least for the SNP density used in the present study, that it is possible to accurately impute the genotypes of a non-genotyped parent from the genotypes of its progeny and there is a benefit of also including the genotype of the sire’s mate (i.e. dam of the progeny).

A study was conducted to estimate the genetic relationship between weaning weight and milk yield in Nguni cattle. Milk yield data (n=125) were collected from 116 Nguni cows from Mara Research Station located in Limpopo Province and Loskop South Farm located in Mpumalanga Province using the weigh-suckle-weigh technique. Weaning weight data (n=19 065) were obtained from stud Nguni cattle from 146 herds distributed throughout South Africa. Estimates of (co)variance components for milk yield and weaning weight were calculated using PEST and VCE softwares. The average weaning weight, age of the calf at weaning and 24-h milk yield was 158.94 kg, 210 days and 5.25 kg/day, respectively. Heritability estimates for milk yield, direct and maternal weaning weight were 0.22±0.238, 0.47±0.039 and 0.25±0.029, respectively. Estimates of genetic correlations for milk yield and maternal weaning weight, milk yield and direct weaning weight, direct and maternal weaning weight were 0.97±0.063, −0.71±0.416 and −0.56±0.247, respectively. The results indicate that maternal weaning weight is genetically highly predictive of milk yield in Nguni cattle. Maternal breeding values for weaning weight could therefore be used as a selection criterion to improve milk yield in Nguni cattle.

Despite single nucleotide polymorphism (SNP) availability and frequent cost reduction has allowed genome-wide association studies even in complex traits as tick resistance, the use of this information source in SNP by environment interaction context is unknown for many economically important traits in cattle. We aimed at identifying putative genomic regions explaining differences in tick resistance in Hereford and Braford cattle under SNP by environment point of view as well as to identify candidate genes derived from outliers/significant markers. The environment was defined as contemporary group means of tick counts, since they seemed to be the most appropriate entities to describe the environmental gradient in beef cattle. A total of 4363 animals having tick counts (n=10 673) originated from 197 sires and 3966 dams were used. Genotypes were acquired on 3591 of these cattle. From top 1% SNPs (410) having the greatest effects in each environment, 75 were consistently relevant in all environments, which indicated SNP by environment interaction. The outliers/significant SNPs were mapped on chromosomes 1, 2, 5, 6, 7, 9, 11, 13, 14, 15, 16, 18, 21, 23, 24, 26 and 28, and potential candidate genes were detected across environments. The presence of SNP by environment interaction for tick resistance indicates that genetic expression of resistance depends upon tick burden. Markers with major portion of genetic variance explained across environments appeared to be close to genes with different direct or indirect functions related to immune system, inflammatory process and mechanisms of tissue destruction/repair, such as energy metabolism and cell differentiation.

The Brangus breed was developed to combine the superior characteristics of both of its founder breeds, Angus and Brahman. It combines the high adaptability to tropical and subtropical environments, disease resistance, and overall hardiness of Zebu cattle with the reproductive potential and carcass quality of Angus. It is known that the major histocompatibility complex (MHC, also known as bovine leucocyte antigen: BoLA), located on chromosome 23, encodes several genes involved in the adaptive immune response and may be responsible for adaptation to harsh environments. The objective of this work was to evaluate whether the local breed ancestry percentages in the BoLA locus of a Brangus population diverged from the estimated genome-wide proportions and to identify signatures of positive selection in this genomic region. For this, 167 animals (100 Brangus, 45 Angus and 22 Brahman) were genotyped using a high-density single nucleotide polymorphism array. The local ancestry analysis showed that more than half of the haplotypes (55.0%) shared a Brahman origin. This value was significantly different from the global genome-wide proportion estimated by cluster analysis (34.7% Brahman), and the proportion expected by pedigree (37.5% Brahman). The analysis of selection signatures by genetic differentiation (Fst) and extended haplotype homozygosity-based methods (iHS and Rsb) revealed 10 and seven candidate regions, respectively. The analysis of the genes located within these candidate regions showed mainly genes involved in immune response-related pathway, while other genes and pathways were also observed (cell surface signalling pathways, membrane proteins and ion-binding proteins). Our results suggest that the BoLA region of Brangus cattle may have been enriched with Brahman haplotypes as a consequence of selection processes to promote adaptation to subtropical environments.

We studied the genetics of cheese-related latent variables (factors; Fs) for application in dairy cattle breeding. In total, 26 traits, recorded in 1264 Brown Swiss cows, were analyzed through multivariate factor analysis (MFA). Traits analyzed were descriptors of milk quality and yield (including protein fractions) and measures of coagulation, curd firmness (CF), cheese yields (%CY) and nutrient recoveries in the curd (REC). A total of 10 Fs (mutual orthogonal with a varimax rotation) were obtained. To assess the practical use of the Fs into breeding, we inferred their genetic parameters using single and bivariate animal models under a Bayesian framework. Heritability estimates (intra-herd) varied between 0.11 and 0.72 (F3: Yield and F7: κ-β-CN, respectively). The Fs underlined basic characteristics of the cheese-making process, milk components and udder health, while retaining 74% of the original variability. The first two Fs were indicators of the CY percentage (F1: %CY) and the CF process (F2: CFt), and presented similar heritability estimates: 0.268 and 0.295, respectively. The third factor was associated with the yield of milk and solids (F3: Yield) characterized by a low heritability (0.108) and the fourth with the cheese nitrogen (N) (F4: Cheese N) that conversely appeared to be characterized by a high heritability (0.618). Three Fs were associated with the proportion of the basic milk caseins on total milk protein (F5: as1-β-CN, F7: κ-β-CN, F8: as2-CN), also highly heritable (0.565, 0.723 and 0.397, respectively) and 1 factor with the phosphorylated form of the as1-CN (F9: as1-CN-Ph; 0.318). Moreover, 1 factor was linked to the whey protein α-LA (F10: α-LA; 0.147). An indicator factor of a cow’s udder health (F6: Udder health) was also obtained and showed a moderate heritability (0.204). Although the Fs were phenotypically uncorrelated, considerable additive genetic correlations existed among them, with highest values observed between F10: α-LA and F6: Udder health (−0.67) as well as between F9: as1-CN-Ph and F3: Yield (−0.60). Our results show the usefulness of MFA in dairy cattle breeding. The ability to replace a large number of variables with a few latent indicators of the same biological meaning marks MFA as a valuable tool for developing breeding strategies to improve cow’s cheese-related traits.

In nutrition studies, para-aminohippuric acid (PAH) is a marker frequently used to measure blood flow in pigs, which is essential for estimating portal-drained viscera (PDV) flux of nutrients. The aim of this study was to evaluate the PAH analytical method by means of qualimetric statistical procedures to estimate the matrix effect and the accuracy and limits of quantitation of the method. Net PDV flux of nutrients was determined in five multi-catheterized pigs using water, plasma or commercial serum as standard matrix. A proportional systematic error due to matrix effect was found for plasma and serum. Mean recovery was 99.4%, and intra- and inter-day precision of the method was 2.4% and 3.8% relative standard deviation, respectively. The limit of quantification was 0.22 mg PAH/l. Use of water for the PAH standard curves underestimated portal blood flow compared with PAH standards prepared with plasma or commercial serum (706, 954 and 927 ml/min; P<0.05, respectively). Consequently, PDV O2 consumption, glucose and amino acids fluxes were underestimated by 33% (P<0.001). In conclusion, our results stress the importance of using plasma from pigs not infused with PAH or alternatively commercial pig serum to prepare PAH standards to determine blood flow in pigs to avoid underestimation of blood flow.

The objectives of this study were to determine the effect and mode of action of Saccharomyces cerevisiae (YST2) on enteric methane (CH4) mitigation in pigs. A total of 12 Duroc×Landrace×Yorkshire male finisher pigs (60±1 kg), housed individually in open-circuit respiration chambers, were randomly assigned to two dietary groups: a basal diet (control); and a basal diet supplemented with 3 g/YST2 (1.8×1010 live cells/g) per kg diet. At the end of 32-day experiment, pigs were sacrificed and redox potential (Eh), pH, volatile fatty acid concentration, densities of methanogens and acetogens, and expression of methyl coenzyme-M reductase subunit A gene were determined in digesta contents from the cecum, colon and rectum. Results showed that S. cerevisiae YST2 decreased (P<0.05) the average daily enteric CH4 production by 25.3%, lowered the pH value from 6.99 to 6.69 in the rectum, and increased the Eh value in cecum and colon by up to −55 mV (P<0.05). Fermentation patterns were also altered by supplementation of YST2 as reflected by the lower acetate, and higher propionate molar proportion in the cecum and colon (P<0.05), resulting in lower acetate : propionate ratio (P<0.05). Moreover, there was a 61% decrease in Methanobrevibacter species in the upper colon (P<0.05) and a 19% increase in the acetogen community in the cecum (P<0.05) of treated pigs. Results of our study concluded that supplementation of S. cerevisiae YST2 at 3 g/kg substantially decreased enteric CH4 production in pigs.

In the present study, grape pomace (GP) was used as feed additive in the diet of weaned piglets in order to develop innovative feedstuffs and to investigate their potential beneficial effects on welfare, productivity and meat quality. For examining the antioxidant capacity of the experimental feeds, 24 piglets of 20 days old were assigned to two experimental groups receiving standard or experimental diet for 30 days. Blood and tissues collections were performed at four different time-points, 2, 20, 35 and 50 days post birth. The collected tissues were brain, heart, kidney, liver, lung, quadriceps muscle, pancreas, spleen and stomach. The following oxidative stress markers were assessed: reduced glutathione (GSH), catalase activity, total antioxidant capacity (TAC), thiobarbituric acid reactive substances (TBARS), protein carbonyls (CARB) and H2O2 decomposition activity. The effect on bacterial growth was assessed by examining microbial populations in piglets’ fecal microbiota. Furthermore, the average daily gain (ADG) was calculated and the fatty acid profile of quadriceps muscle was assessed. The results showed that piglets fed with the diet supplemented with GP, had significantly increased antioxidants mechanisms in almost all the tissues as shown by increases in GSH, H2O2 decomposition activity and TAC compared with control group. Piglets fed with the experimental diet exhibited decreased oxidative stress-induced damage to lipids and proteins as shown by decreases in TBARS and CARB in GP group compared with control. In addition, the experimental diet increased significantly ADG (by 23.65%) (P<0.05) and enhanced the growth of facultative probiotic bacteria (by up to 1.2 log colony forming units (CFU)/g) (P<0.05) and lactic acid bacteria (by up to 2.0 log CFU/g) (P<0.05) in GP group compared with the control group. GP supplementation inhibited the growth of pathogen populations such as Enterobacteriacae (by up to 1.8 log CFU/g) (P<0.05) and Campylobacter jejuni (by up to 1.0 log CFU/g) (P<0.05). Regarding fatty acid composition of meat, GP inclusion in piglets’ diet increased significantly n-3 fatty acids (EPA; C20 : 5n-3, DHA; C22 : 6n-3, α-linolenic acid; C18 : 3n-3) and decreased significantly n-6/n-3 ratio compared with control (P<0.05). The results suggested that dietary GP supplementation may have a beneficial impact on piglets’ welfare and may improve productivity as well as meat quality.

The objective of this study was to evaluate the effects of the energy restriction of gestation of adult ewes from day 45 to day 115 on lamb live performance parameters, carcass and meat traits. In experiment I, dietary energy was restricted at 70% of the metabolizable energy (ME) requirements, after which ewes were re-fed ad libitum until lambing. In experiment II, dietary energy was restricted at 60% of the ME requirements, and ewes were re-fed to ME requirements until lambing. All ewes grazed together from the end of the restriction periods to weaning. Lambs were weaned and lot fed until slaughter. Feed intake, weight gain and feed efficiency were recorded, and body fat thickness and ribeye area (REA) were measured in the longissimus thoracis muscle. After slaughter, carcass weight and yield, fat depth, carcass and leg length, and frenched rack and leg weights and yields were determined. Muscle fiber type composition, Warner-Bratzler shear force, pH and color were determined in the longissimus lumborum muscle. In experiment I, energy restriction followed by ad libitum feeding affected lamb birth weight (P<0.05); however, no effects (P>0.05) were observed on later BW, REA, BF or carcass traits. Lambs born to non-restricted-fed ewes had higher (P<0.05) weight and yield of the frenched rack cut and their meat tended (P=0.11) to be tender compared with that of lambs from restricted ewes. The percentage of oxidative muscle fibers was lower for lambs born to non-restricted ewes (P<0.05); however, no effects of ewe treatment were observed on other muscle fiber types. For experiment II, energy restriction followed by ME requirements feeding, affected (P<0.01) pre-weaning live weight gain, weaning and final weights. Lambs from restricted ewes had higher (P<0.05) feed intake as % of leg weight and a trend to be less efficient (P=0.16) than lambs from unrestricted dams. Ribeye area and BF were not influenced by treatment. Treatment significantly affected slaughter weight, but had no effects on carcass yield and traits or on meat traits. The results obtained in both experiments indicate submitting ewes to energy restriction during gestation affects the performance of their progeny but the final outcome would depend on the ewe’s re-feeding level during late gestation and the capacity of the offspring to compensate the in utero restriction after birth.

In the context of determining the sustainable carrying capacity of dry-Mediterranean herbaceous rangelands, we examined the effect of animal density on cattle nutrition, which is fundamental to animal performance and welfare. The effects on dietary components of low (0.56 cows/ha; L) and high (1.11 cows/ha; H) animal densities were monitored for three consecutive years in grazing beef cows. In the dry season (summer and early autumn), cows had free access to N-rich poultry litter (PL) given as a dietary supplement. In each season, near-IR spectroscopy (NIRS) was used to predict the chemical composition of herbage samples (ash, NDF, CP, in vitro dry matter digestibility (IVDMD) and metabolizable energy (ME) content from IVDMD). Near-IR spectroscopy was applied also to faecal samples to determine the chemical composition of the diet selected by the animal, as well as the contents of ash, NDF and CP in the faeces themselves. A faecal-NIRS equation was applied to estimate the dietary proportion of PL. Seasonal categories were green, dry without PL supplementation and dry with it. We found no effects of animal density on nutrition during the green season but effects were apparent when cows consumed dry pasture. Ash content predicted by faecal NIRS was higher in the diet than in plant samples clipped from pasture, which infers that cows ingested soil. Dietary and faecal ash contents were higher (P<0.05) at the H, implying greater soil intake in these animals. During the dry period, dietary contents of ME were higher in L than in H (P<0.05). Poultry litter supplementation was associated with a marked increase (P<0.01) in dietary and faecal CP contents. Poultry litter represented 0.45 and 0.59 of the diet in treatments L and H, respectively (P<0.05). Consequently, treatment H had higher faecal protein (P<0.05). A tendency of higher dietary protein (P=0.08) and lower dietary NDF (P=0.10) in treatment H was probably related to greater PL ingestion. Given that high and sustained rates of poultry litter consumption are detrimental to animal health, the above results cast doubts on the long-term sustainability of the higher of the animal densities tested. Although it may be sustainable vis-à-vis the vegetation, treatment H may have exceeded the boundaries of what is acceptable for cow health. Chemical information revealed with NIRS can be used to evaluate whether animal densities are compatible with animal health and welfare standards and can play a role in determining the carrying capacity of Mediterranean rangelands.

Current trends in the beef industry focus on selecting production traits with the purpose of maximizing calf weaning weight; however, such traits may ultimately decrease overall post-weaning productivity. Therefore, the objective of this study was to evaluate the effects of actual milk yield in mature beef cows on their offspring’s dry matter intake (DMI), BW, average daily gain, feed conversion ratio (FCR) and residual feed intake (RFI) during a ~75-day backgrounding feeding trial. A period of 24-h milk production was measured with a modified weigh-suckle-weigh technique using a milking machine. After milking, cows were retrospectively classified as one of three milk yield groups: Lower (6.57±1.21 kg), Moderate (9.02±0.60 kg) or Higher (11.97±1.46 kg). Calves from Moderate and Higher milk yielding dams had greater (P<0.01) BW from day 0 until day 75 at the end of the backgrounding feeding phase; however, day 75 BW were not different (P=0.36) between Lower and Moderate calves. Body weight gain was greater (P=0.05) for Lower and Moderate calves from the day 0 BW to day 35 BW compared with Higher calves. Overall DMI was lower (P=0.03) in offspring from Lower and Moderate cows compared with their Higher milking counterparts. With the decreased DMI, FCR was lower (P=0.03) from day 0 to day 35 in calves from Lower and Moderate milk yielding dams. In addition, overall FCR was lower (P=0.02) in calves from Lower and Moderate milk yielding dams compared with calves from Higher milk yielding dams. However, calving of Lower milk yielding dams had an increased (P=0.04) efficiency from a negative RFI value compared with calves from Moderate and Higher milking dams. Results from this study suggest that increased milk production in beef cows decreases feed efficiency during a 75-day post-weaning, backgrounding period of progeny.

Adding nitrate to or increasing the concentration of lipid in the diet are established strategies for reducing enteric methane (CH4) emissions, but their effectiveness when used in combination has been largely unexplored. This study investigated the effect of dietary nitrate and increased lipid included alone or together on CH4 emissions and performance traits of finishing beef cattle. The experiment was a 2×4 factorial design comprising two breeds (cross-bred Aberdeen Angus (AAx) and cross-bred Limousin (LIMx) steers) and four dietary treatments (each based on 550 g forage : 450 g concentrate/kg dry matter (DM)). The four dietary treatments were assigned according to a 2×2 factorial design where the control treatment contained rapeseed meal as the main protein source, which was replaced either with nitrate (21.5 g nitrate/kg DM); maize distillers dark grains (MDDG, which increased diet ether extract from 24 to 37 g/kg DM) or both nitrate and MDDG. Steers (n=20/dietary treatment) were allocated to each of the four treatments in equal numbers of each breed with feed offered ad libitum. After 28 days adaptation to dietary treatments, individual animal intake, performance and feed efficiency were recorded for 56 days. Thereafter, CH4 emissions were measured over 13 weeks (six steers/week). Increasing dietary lipid did not adversely affect animal performance and showed no interactions with dietary nitrate. In contrast, addition of nitrate to diets resulted in poorer live-weight gain (P<0.01) and increased feed conversion ratio (P<0.05) compared with diets not containing nitrate. Daily CH4 output was lower (P<0.001) on nitrate-containing diets but increasing dietary lipid resulted in only a non-significant reduction in CH4. There were no interactions associated with CH4 emissions between dietary nitrate and lipid. Cross-bred Aberdeen Angus steers achieved greater live-weight gains (P<0.01), but had greater DM intakes (P<0.001), greater fat depth (P<0.01) and poorer residual feed intakes (P<0.01) than LIMx steers. Cross-bred Aberdeen Angus steers had higher daily CH4 outputs (P<0.001) but emitted less CH4 per kilogram DM intake than LIMx steers (P<0.05). In conclusion, inclusion of nitrate reduced CH4 emissions in growing beef cattle although the efficacy of nitrate was less than in previous work. When increased dietary lipid and nitrate inclusion were combined there was no evidence of an interaction between treatments and therefore combining different nutritional treatments to mitigate CH4 emissions could be a useful means of achieving reductions in CH4 while minimising any adverse effects.

Fetuin A (also known as α2-Heremans–Schmid glycoprotein) is a protein primarily expressed by the liver and secreted into the blood. Previous studies have suggested that plasma concentrations of fetuin A are elevated with impaired growth rate in swine. The present study was designed to examine the relationship of porcine fetuin A with growth rate in the pig and to also elucidate the regulation of fetuin A expression by examining the hormonal and cytokine regulation of fetuin A mRNA abundance in hepatocytes prepared from suckling piglets. Quantitative real-time PCR assay was used to quantify the number of fetuin A mRNA molecules/molecule cyclophilin mRNA. Total RNA was isolated from liver of three different groups of pigs to assess changes in mRNA abundance of fetuin A: normal piglets at day 1, day 7 day 21 or 6 months of age (n=6 for each age); runt and control piglets at day 1 of age (n=4); slow growing and normal growing piglets at 21 days of age (n=8). Following birth, fetuin A gene expression increased from day 1 and 7 of age (P<0.05), and then declined at 21 days of age (P<0.05), with a much greater decline to 6 months of age (P<0.01). Fetuin A mRNA abundance was higher in runt pigs v. their normal birth weight littermates (P<0.05). Similarly, fetuin A gene expression was higher in livers of pigs that were born at a normal weight but that grew much slower than littermates with the same birth weight (P<0.05). Hepatocytes were isolated from preweaned piglets and maintained in serum-free monolayer culture for up to 72 h to permit examination of the influences of hormones, cytokines and redox modifiers on fetuin A mRNA abundance. Fetuin A gene expression was enhanced by glucagon, T3 and resveratrol (P<0.05). Growth hormone, cytokines (interleukin6, tumor necrosis factor-α) and antioxidants (N-acetylcysteine, quercertin) reduced fetuin A mRNA abundance (P<0.05). A role for fetuin A in postnatal development is suggested by the differences in fetuin A mRNA abundance between runt piglets or slow growing piglets and their normal growing sized littermates. The hepatocyte experiments suggest multiple hormones and cytokines may contribute to the regulation of fetuin A during early growth of the pig.

Frequent BW monitoring of growing pigs can be useful for identifying production (e.g. feeding), health and welfare problems. However, in order to construct a tool which will properly recognize abnormalities in pigs’ growth a precise description of the growth process should be used. In this study we proposed a new model of pig growth accounting for daily fluctuations in BW. Body weight measurements of 1710 pigs (865 gilts and 843 barrows) originating from five consecutive batches from a Danish commercial farm were collected. Pigs were inserted into a large pen (maximum capacity=400) between November 2014 and September 2015. On average, each pig was observed for 42 days and weighed 3.6 times a day when passing from the resting to feeding area. Altogether, 243,160 BW measurements were recorded. A multilevel model of pig growth was constructed and fitted to available data. The BW of pigs was modeled as a quadratic function of time. A diurnal pattern was incorporated into the model by a cosine wave with known length (24 h). The model included pig effect which was defined as a random autoregressive process with exponential correlation. Variance of within-pigs error was assumed to increase with time. Because only five batches were observed, it was not possible to obtain the random effect for batch. However, in order to account for the batch effect the model included interactions between batch and fixed parameters: intercept, time, square value of time and cosine wave. The gender effect was not significant and was removed from the final model. For all batches, morning and afternoon peaks in the frequency of visits to the feeding area could be distinguished. According to results, pigs were lighter in the morning and heavier in the evening (minimum BW was reached around 1000 h and maximum around 2200 h). However, the exact time of obtaining maximum and minimum BW during the day differed between batches. Pigs had access to natural light and, therefore, existing differences could be explained by varying daylight level during observations periods. Because the diurnal amplitude for pig growth varied between batches from 0.9 to 1.4 kg, BW monitoring tools based on frequent measurements should account for diurnal variation in BW of pigs. This proposed description of growth will be built into a monitoring tool (a dynamic linear model) and applied to farm data in future studies.

Azaperone treatment can control aggression and decrease stress due to weaning, re-grouping and hierarchical fighting of gilts and sows. However, the effects of this butyrophenone neuroleptic and sedative administered at weaning on pig reproductive function are poorly characterized. In this year-long study, a total of 619 cross-bred sows (Polish Large White×Polish Landrace) kept on a commercial farm received an i.m. injection of azaperone (Stresnil®; 2 mg/kg BW) just before weaning and were artificially inseminated during the ensuing estrus with 3×109 spermatozoa per dose of an inseminate; 1180 sows served as untreated controls. Immediately after weaning, the sows were moved to four pens of seven to nine animals each. A teaser boar was used twice daily to check for estrus and sows were bred at heat detection. Subsequently, all sows stayed in individual stalls until pregnancy testing on day 30 post-artificial insemination and were then re-grouped until farrowing. The proportion of pigs that were in estrus within 6 days post-weaning was significantly lower in azaperone-treated groups of animals than in controls (71.4% v. 84.2%). Overall, the azaperone-treated sows had a significantly longer weaning-to-estrus interval (WEI; 8.7±10.1 v. 6.3±8.1 days; mean±SD) and a significantly larger litter size (LS: 11.8±3.0 v.11.3±3.2; azaperone-treated v. control sows). Treatment of the winter-farrowing sows was associated with increased LS (12.8±2.6 and 11.3±3.1 piglets/sow, respectively; P<0.05) and longer (P<0.05) weaning-to-effective-service intervals (11.7±19.3 and 8.4±12.3 days, respectively) as well as farrowing intervals (155.7±19.7 and 152.2±16.1 days, respectively) compared with untreated controls. In the summer months, significantly longer WEIs (12.1±21.0 v. 8.4±16.9 days) were accompanied by a significant decline in LS only in azaperone-treated sows that were inseminated within 6 days post-weaning (10.8±2.9 v. 11.5±3.3 piglets/sow; azaperone-treated v. controls). Azaperone-treated second parity sows had greater LS (P<0.001) along with prolonged WEIs (P<0.05) in comparison to their respective controls, regardless of the timing of estrus. An application of azaperone at weaning increased the annual piglet productivity of winter-farrowing animals and of second parity sows but depressed it significantly in summer. The extra cost and labor due to delayed onset of estrus may cancel out any reproductive benefits of azaperone treatment.

The aim of this study is to determine the effects of early and mid-gestation nutrient restriction on maternal metabolites and foetal growth. Primiparous Angus cows were synchronized and inseminated with semen from one sire. Dietary treatments were: control to gain 1 kg/week (CON) or 0.55% maintenance energy and CP requirements (nutrient restricted; NR). A subset of dams was fed NR (n=8) or CON (n=8) from days 30 to 110 of gestation. Another group was fed CON (n=8), days 30 to 190; NR (n=7), days 30 to 110 followed by CON days 110 to 190; or CON, (n=7) days 30 to 110 followed by NR days 110 to 190. Cows were harvested at days 110 or 190 of gestation, when foetal measurements and samples were collected. Cows that were NR during days 30 to 110 or 110 to 190 of gestation lost significant BW and body condition score (P<0.001), this was associated with reduced plasma glucose during NR (P<0.002). Foetal weights, empty foetal weights, abdominal and thoracic circumferences were all reduced (P<0.03) in day 110 NR animals. Foetal perirenal adipose as a percentage of empty foetal weight was increased (P=0.01) in NR day 110 female foetuses compared with CON foetus. Maternal serum triglycerides at day 110 of gestation were decreased (P<0.05) in NR dams, whereas foetal serum triglycerides were increased (P<0.05) in response to maternal NR. Foetal weights tended to be reduced (P=0.08) in NR/CON and CON/NR v. CON/CON cattle at day 190 of gestation. Empty foetal weights, abdominal and thoracic circumferences were reduced (P⩽0.03) in NR/CON and CON/NR v. CON/CON cattle. Brain weight as a percentage of empty foetal weight was increased (P<0.001) in NR/CON and CON/NR v. CON/CON cattle. Foetal perirenal adipose as a percentage of empty foetal weight was increased (P=0.003) in NR/CON and CON/NR v. CON/CON cattle. Maternal serum triglycerides at day 190 of gestation were decreased (P<0.05) in association with maternal NR. Foetal serum triglycerides at day 190 of gestation were increased (P<0.05) in response to maternal NR during early gestation but decreased by NR in mid gestation compared with CON foetuses. The data show that maternal nutrient restriction during early or mid-gestation cause’s asymmetrical foetal growth restriction, regardless if the restriction is preceded or followed by a period of non-restriction.

This review assesses factors affecting fouling in conventional pens for slaughter pigs. Fouling of the pen happens when pigs change their excretory behaviour from occurring in the designated dunging area to the lying area. This can result in a lower hygiene, bad air quality, extra work for the farmer, disturbance of the pigs’ resting behaviour and an increase in agonistic interactions. A systematic search was conducted and results narrowed down to 21 articles. Four factors were found to affect fouling directly: insufficient space allowance, the flooring design of the pen, the thermal climate and pigs’ earlier experience. Further, these primary factors are affected by secondary factors such as the shape of the pen, the weight of the pigs and especially the heat balance of the pigs, which is affected by several tertiary factors including, for example, temperature, humidity and draught. Results indicate that the most important factor to control when trying to prevent fouling of a pen is the pen climate. An appropriate climate may be accomplished through floor cooling in the designated lying area, sprinklers above the designated dunging area and by ensuring a more optimal ambient temperature curve that also fits the weight of the pigs in different stages of the production. All in all, fouling of the pen in conventional slaughter pigs is a multifactorial problem, but it is important to focus on increasing the comfortability, and especially the climate, of the designated lying area.

We investigated the effect of offering supplementary dietary fibres to suckling piglets on their behaviour and performance before weaning. From 5 to 22 days of age, suckling piglets were offered a high-fibre diet (HF; 5% cellulose; n=5 litters), or a control low-fibre diet (n=5 litters). Piglets were housed with the sows in individual farrowing pens, and had access to maternal milk until weaning, at 23 days of age. Behaviours of six focal piglets per pen were scored at 6, 16 and 21 days of age. All piglets were individually weighed at 5, 15 and 20 days of age and feed intake was measured daily at the pen level. Piglets on the HF diet were more active than controls (P=0.05), and spent more time suckling or massaging the udder (P=0.01) and interacting with pen mates (P=0.008). Time spent manipulating pen mates, which may reflect re-directed foraging activity in the absence of substrate, accounted for most of the time spent interacting with pen mates (⩾73% of total time spent interacting). Dietary fibres had no effect on BW and feed intake. In conclusion, inclusion of cellulose in the supplemental diet of suckling piglets affects behaviour, with no deleterious effects on performance before weaning.

In the Welfare Quality® assessment protocol for broilers, the touch test is included to assess the human–animal relationship in the flock. The test is designed to measure the animals’ fear of humans, assuming that broilers will withdraw from the observer if they are fearful. However, many broilers close to slaughter age have impaired walking ability, and the results from the touch test may thus be biased by lameness and poor leg health. As the touch test is currently being used in several countries to assess human–animal relationship in broilers, there is an urgent need to examine this potential relationship for a further validation of the test. In the present study, fear of humans was assessed in 50 randomly selected Norwegian broiler flocks, using the touch test as described in the Welfare Quality® protocol for ty broilers. Leg health was assessed by examining the gait of 150 random birds in each of the flocks, using a six-point gait score scale from 0 to 5. The coefficient for the relationship between touch test score and gait score was 0.034 (P<0.001), indicating that the animals express less fear as assessed by the touch test when the gait scores increase. This implies that the touch test may be confounded by impaired walking ability and therefore might be a suboptimal method of assessing fear of humans and human–animal relationship in broilers. In conclusion, the results from this study suggests that the touch test must be further validated in broilers and perhaps be replaced with a fear test that doesn’t rely on walking ability.

Cattle’s relationship with humans is a crucial factor regarding their welfare. In dairy cows, interactions with humans occur regularly during milking. We tested the effect of gentle interactions (stroking, talking in a gentle voice) during milking on avoidance distance and milk composition, yield and flow characteristics as well as behaviour during milking. Over the course of 15 days, an experimenter interacted gently with 14 German Holstein cows for 2 min during morning and evening milkings, totalling 60 min; the experimenter stayed at a similar distance to 12 control cows of the same breed for the same amount of time. There were no significant differences between the groups in behaviour during milking. Over the course of the experimental phase, avoidance distance at the feeding rack decreased significantly in stroked but not in control cows. The treatment did not improve any of the measures of milk composition, yield or flow; on the 1st day of the treatment, milk ejection was impaired in stroked cows, which points towards an effect of the novelty of the treatment. We conclude that gentle interactions during milking improve the relationship between cows and a human. Possible reasons for the absence of an effect on milk characteristics are that cows may not have perceived the interactions as positive or that a ceiling effect occurred due to otherwise optimal milking routines.