Holstein-Friesian steer beef production is renowned globally as a secondary product of the milk industry. Grass feeding is a common practice in raising Holstein steers because of its low cost. Furthermore, grass feeding is an alternative way to produce beef with a balanced n-6 to n-3 fatty acids (FAs) ratio. However, the performance and meat quality of Holstein-Friesian cattle is more likely to depend on a high-quality diet. The aim of this study was to observe whether feeding two mixed diets; a corn-based total mixed ration (TMR) with winter ryegrass (Lolium perenne) or flaxseed oil-supplemented pellets with reed canary grass haylage (n-3 mix) provided benefits on carcass weight, meat quality and FA composition compared with cattle fed with reed canary grass (Phalaris arundinacea) haylage alone. In all, 15 21-month-old Holstein-Friesian steers were randomly assigned to three group pens, were allowed free access to water and were fed different experimental diets for 150 days. Blood samples were taken a week before slaughter. Carcass weight and meat quality were evaluated after slaughter. Plasma lipid levels and aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT), creatine kinase (CK) and alkaline phosphatase (ALP) activities were determined. Diet did not affect plasma triglyceride levels and GGT activity. Plasma cholesterol levels, including low-density and high-density lipoproteins, were higher in both mixed-diet groups than in the haylae group. The highest activities of plasma AST, CK and ALP were observed in the haylage group, followed by n-3 mix and TMR groups, respectively. Carcass weight was lower in the haylage group than in the other groups and no differences were found between the TMR and n-3 mix groups. Although the n-3 mix-fed and haylage-fed beef provided lower n-6 to n-3 FAs ratio than TMR-fed beef, the roasted beef obtained from the TMR group was more acceptable with better overall meat physicochemical properties and sensory scores. According to daily cost, carcass weight and n-6 to n-3 FAs ratio, the finishing diet containing flaxseed oil-supplemented pellets and reed canary grass haylage at the as-fed ratio of 40 : 60 could be beneficial for the production of n-3-enriched beef.

This study was undertaken to provide a thorough analysis of the neutral lipid (NL) and polar lipid (PL) fractions of horse meat that included the content and distribution of acyl and alkenyl moieties in foals under different rearing conditions. Two groups of crossbred horses were studied; the first group was selected from suckling foals produced under grazing conditions and slaughtered at 4 months of age (n=8), and the second group was selected from concentrate-finished foals and slaughtered at 12 months of age (n=7). There were significant differences related to the age and feeding practices of foals which affected the intramuscular (IM) fat content and the fatty acid (FA) composition of NL and PL fractions. Samples from suckling foals were leaner and provided the highest content of methylation products from the plasmalogenic lipids, and total and n-3 polyunsaturated fatty acid (PUFA). By contrast, the meat from concentrate-finished foals had a higher IM fat level resulting in a greater accumulation of 16:0 and total monounsaturated FAs in the NL fraction, whereas the muscle PL fraction retained a similar FA composition between both groups. Linolenic acid was preferentially deposited in the NL fraction, but linoleic acid and the long-chain n-3 and n-6 PUFAs were incorporated into the PL fraction where they served as cell membrane constituents and in eicosanoid formation.

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 objective of this review paper is to describe the development and application of a suite of more than 40 computerized dairy farm decision support tools contained at the University of Wisconsin-Madison (UW) Dairy Management website http://DairyMGT.info. These data-driven decision support tools are aimed to help dairy farmers improve their decision-making, environmental stewardship and economic performance. Dairy farm systems are highly dynamic in which changing market conditions and prices, evolving policies and environmental restrictions together with every time more variable climate conditions determine performance. Dairy farm systems are also highly integrated with heavily interrelated components such as the dairy herd, soils, crops, weather and management. Under these premises, it is critical to evaluate a dairy farm following a dynamic integrated system approach. For this approach, it is crucial to use meaningful data records, which are every time more available. These data records should be used within decision support tools for optimal decision-making and economic performance. Decision support tools in the UW-Dairy Management website (http://DairyMGT.info) had been developed using combination and adaptation of multiple methods together with empirical techniques always with the primary goal for these tools to be: (1) highly user-friendly, (2) using the latest software and computer technologies, (3) farm and user specific, (4) grounded on the best scientific information available, (5) remaining relevant throughout time and (6) providing fast, concrete and simple answers to complex farmers’ questions. DairyMGT.info is a translational innovative research website in various areas of dairy farm management that include nutrition, reproduction, calf and heifer management, replacement, price risk and environment. This paper discusses the development and application of 20 selected (http://DairyMGT.info) decision support tools.

Morphometry has proven to be a useful tool, both for the clinician and horse owners, for evaluating the body condition in equids due to its objectivity, easiness and capacity for detection of important metabolic disturbances. However, limited information is available on the use of morphometric ratios to characterize regional and overall adiposity and much less about their application in different genders, ages and horses with different levels of obesity. The objectives were to evaluate body and neck absolute measurements and ratios; factors affecting them such as the influence of gender, age, appearance of the neck crest and overall body condition and; relationships among these measurements. A total of 154 Andalusian horses classified according to their gender, age, body score status and cresty neck condition were evaluated in this cross-sectional study. Two evaluators assigned a body condition score (BCS, 1 to 9) and a cresty neck score (CNS, 0 to 5) to each horse. Horses were divided into males and females; young (2 to 5 years) and adults (6 to 15 years); obese (BCS⩾7) and non-obese (BCS<7); cresty neck (CNS⩾3) and non-cresty neck horses (CNS<3). Morphometric measurements (cm) included were: height at the withers (HW); body length (BL), girth (GC) and waist (WC) circumferences; neck length (NL); three neck circumferences (NCs), over the first (NC25%), the second (NC50%) and the third part (NC75%) of the NL and neck crest height (NCH). These measurements were also used to calculate the following ratios: GC : HW, WC : HW, GC : BL, WC : BL, NC25% : HW, NC50% : HW, NC75% : HW, NC25% : BL, NC50% : BL, NC75% : BL, NC25% : NL, NC50% : NL, NC75% : NL, NC25% : NCH, NC50% : NCH and NC75% : NCH. The results showed that most of the absolute measurements and ratios were greater than those described in other light breeds. In addition, most neck ratios were higher (P<0.050) in males than in females, however, all body ratios were greater (P<0.001) in females. Among the absolute measurements, WC in obese horses and NC25% and NC75% in cresty neck horses highlighted as higher. Either GC : HW or WC : HW and NC75% : BL were alternative surrogates for the appraisal of overall and regional adiposity in Andalusians. Several interactions were observed between the gender and adiposity scoring systems affecting the morphometric evaluation. This study establishes absolute morphometric measurements and ratios in Andalusian horses. It also highlights the variability of morphometric values and how the outcome of these can be influenced by demographic variables and the breed analyzed. Further studies are necessary to set morphometric reference values in other breeds.

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).

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.

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.

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.

Little is known about cheese-making efficiency at the individual cow level, so our objective was to study the effects of herd productivity, individual herd within productivity class and breed of cow within herd by producing, then analyzing, 508 model cheeses from the milk of 508 cows of six different breeds reared in 41 multi-breed herds classified into two productivity classes (high v. low). For each cow we obtained six milk composition traits; four milk nutrient (fat, protein, solids and energy) recovery traits (REC) in curd; three actual % cheese yield traits (%CY); two theoretical %CYs (fresh cheese and cheese solids) calculated from milk composition; two overall cheese-making efficiencies (% ratio of actual to theoretical %CYs); daily milk yield (dMY); and three actual daily cheese yield traits (dCY). The aforementioned phenotypes were analyzed using a mixed model which included the fixed effects of herd productivity, parity, days in milk (DIM) and breed; the random effects were the water bath, vat, herd and residual. Cows reared in high-productivity herds yielded more milk with higher nutrient contents and more cheese per day, had greater theoretical %CY, and lower cheese-making efficiency than low-productivity herds, but there were no differences between them in terms of REC traits. Individual herd within productivity class was an intermediate source of total variation in REC, %CY and efficiency traits (10.0% to 17.2%), and a major source of variation in milk yield and dCY traits (43.1% to 46.3%). Parity of cows was an important source of variation for productivity traits, whereas DIM affected almost all traits. Breed within herd greatly affected all traits. Holsteins produced more milk, but Brown Swiss cows produced milk with higher actual and theoretical %CYs and cheese-making efficiency, so that the two large-framed breeds had the same dCY. Compared with the two large-framed breeds, the small Jersey cows produced much less milk, but with greater actual and theoretical %CYs, similar efficiencies and a slightly lower dCY. Compared with the average of the specialized dairy breeds, the three dual-purpose breeds (Simmental and the local Rendena and Alpine Grey) had, on average, similar dMY, lower actual and theoretical %CY, similar fat and protein REC, and slightly greater cheese-making efficiency.

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.

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.

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.

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.

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.

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.

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.