Livestock production is a major contributor to greenhouse gas (GHG) emissions, so will play a significant role in the mitigation effort. Recent literature highlights different strategies to mitigate GHG emissions in the livestock sector. Animal welfare is a criterion of sustainability and any strategy designed to reduce the carbon footprint of livestock production should consider animal welfare amongst other sustainability metrics. We discuss and tabulate the likely relationships and trade-offs between the GHG mitigation potential of mitigation strategies and their welfare consequences, focusing on ruminant species and on cattle in particular. The major livestock GHG mitigation strategies were classified according to their mitigation approach as reducing total emissions (inhibiting methane production in the rumen), or reducing emissions intensity (Ei; reducing CH4 per output unit without directly targeting methanogenesis). Strategies classified as antimethanogenic included chemical inhibitors, electron acceptors (i.e. nitrates), ionophores (i.e. Monensin) and dietary lipids. Increasing diet digestibility, intensive housing, improving health and welfare, increasing reproductive efficiency and breeding for higher productivity were categorized as strategies that reduce Ei. Strategies that increase productivity are very promising ways to reduce the livestock carbon footprint, though in intensive systems this is likely to be achieved at the cost of welfare. Other strategies can effectively reduce GHG emissions whilst simultaneously improving animal welfare (e.g. feed supplementation or improving health). These win–win strategies should be strongly supported as they address both environmental and ethical sustainability. In order to identify the most cost-effective measures for improving environmental sustainability of livestock production, the consequences of current and future strategies for animal welfare must be scrutinized and contrasted against their effectiveness in mitigating climate change.

Satellite cells are adult stem cells located between the basal lamina and sarcolemma of muscle fibers. Under physiological conditions, satellite cells are quiescent, but they maintain a strong proliferative potential and propensity to differentiate, which underlies their critical role in muscle preservation and growth. MicroRNAs (miRNAs) play essential roles during animal development as well as in stem cell self-renewal and differentiation regulation. MiRNA-1, miRNA-133a and miRNA-206 are closely related muscle-specific miRNAs, and are thus defined myomiRNAs. MyomiRNAs are integrated into myogenic regulatory networks. Their expression is under the transcriptional and post-transcriptional control of myogenic factors and, in turn, they exhibit widespread control of muscle gene expression. Very little information is available about the regulation and behavior of satellite cells in large farm animals, in particular during satellite cell differentiation. Here, we study bovine satellite cells (BoSCs) undergoing a differentiation process and report the expression pattern of selected genes and miRNAs involved. Muscle samples of longissimus thoracis from Holstein adult male animals were selected for the collection of satellite cells. All satellite cell preparations demonstrated myotube differentiation. To characterize the dynamics of several transcription factors expressed in BoSCs, we performed real-time PCR on complementary DNA generated from the total RNA extracted from BoSCs cultivated in growth medium (GM) or in differentiation medium (DM) for 4 days. In the GM condition, BoSCs expressed the satellite cell lineage markers as well as transcripts for the myogenic regulatory factors. At the time of isolation from muscle, PAX7 was expressed in nearly 100% of BoSCs; however, its messenger RNA (mRNA) levels dramatically decreased between 3 and 6 days post isolation (P<0.01). MyoD mRNA levels increased during the 1st day of cultivation in DM (day 7; P<0.02), showing a gradual activation of the myogenic gene program. During the subsequent 4 days of culture in DM, several tested genes, including MRF4, MYOG, MEF2C, TMEM8C, DES and MYH1, showed increased expression (P<0.05), and these levels remained high throughout the culture period investigated. Meanwhile, the expression of genes involved in the differentiation process also miRNA-1, miRNA-133a and miRNA-206 were strongly up-regulated on the 1st day in DM (day 7; P<0.05). Analysis revealed highly significant correlations between myomiRNAs expression and MEF2C, MRF4, TMEM8C, DES and MYH1 gene expression (P<0.001). Knowledge about the transcriptional changes correlating with the growth and differentiation of skeletal muscle fibers could be helpful for developing strategies to improve production performance in livestock.

Supplementing dairy cow diets with oilseed preparations has been shown to replace milk saturated fatty acids (SFA) with mono- and/or polyunsaturated fatty acids (MUFA, PUFA), which may reduce risk factors associated with cardio-metabolic diseases in humans consuming milk and dairy products. Previous studies demonstrating this are largely detailed, highly controlled experiments involving small numbers of animals, but in order to transfer this feeding strategy to commercial situations further studies are required involving whole herds varying in management practices. In experiment 1, three oilseed supplements (extruded linseed (EL), calcium salts of palm and linseed oil (CPLO) and milled rapeseed (MR)) were included in grass silage-based diets formulated to provide cows with ~350 g oil/day, and compared with a negative control (Control) diet containing no supplemental fat, and a positive control diet containing 350 g/cow per day oil as calcium salt of palm oil distillate (CPO). Diets were fed for 28-day periods in a 5×4 Latin Square design, and milk production, composition and fatty acid (FA) profile were analysed at the end of each period. Compared with Control, all lipid supplemented diets decreased milk fat SFA concentration by an average of 3.5 g/100 g FA, by replacement with both cis- and trans-MUFA/PUFA. Compared with CPO, only CPLO and MR resulted in lower milk SFA concentrations. In experiment 2, 24 commercial dairy farms (average herd size±SEM 191±19.3) from the south west of the United Kingdom were recruited and for a 1 month period asked to supplement their herd diets with either CPO, EL, CPLO or MR at the same inclusion level as the first study. Bulk tank milk was analysed weekly to determine FA concentration by Fourier Transform mid-IR spectroscopy prediction. After 4 weeks, EL, CPLO and MR all decreased herd milk SFA and increased MUFA to a similar extent (average −3.4 and +2.4 g/100 g FA, respectively) when compared with CPO. Differing responses observed between experiments 1 and 2 may be due in part to variations in farm management conditions (including basal diet) in experiment 2. This study demonstrates the importance of applying experimental research into commercial practice where variations in background conditions can augment different effects to those obtained under controlled conditions.

Ova ageing is the most important factor affecting fish egg quality after ovulation. Long-term storage of fish ova, using cryopreservation and vitrification techniques, has been unsuccessful to date. Instead, short-term in vitro ova storage has been used successfully and optimized in some cultured fish species. In vitro ova storage can drastically improve mass production of larvae and juveniles in the hatcheries by providing the possibility of the synchronous artificial fertilization for different females. To study how long unfertilized eggs of Eurasian perch (Perca fluviatilis L.) can retain their fertilizing ability after stripping, eggs were stored at temperatures of 4°C, 8°C and 12°C for 72 h post-stripping (HPS). The stored eggs of four female perch were separately fertilized at 0 h (i.e. control eggs fertilized before storage) and at 6-hour intervals during the experimental period of 72 h. The embryos reaching the eyed-egg and hatched-larvae stages, eyed-egg mortality and larval malformation rates were recorded as indices of egg quality. The results indicated that the maximum eyed eggs and hatched larvae (86% and 63%, respectively) were observed for eggs fertilized immediately after stripping, whereas the storage of the eggs at 4°C for 48 HPS decreased the eyed-egg and hatched-larvae rates to 46% and 17%, respectively. The use of a higher storage temperature resulted in a more rapid decrease in egg viability: eyed-egg and hatched-larvae rates of 23% and 9%, respectively, were obtained after 48 HPS storage at 8°C and 2% and 1% for eggs stored at 12°C. Eyed-egg mortality and larval malformation rates were not significantly affected by post-stripping ova ageing for at least up to 36 h. Thereafter, both values increased significantly and were measured to be the highest in the most aged ova. The present study demonstrated that stripped Eurasian perch eggs can be stored for at least 12 h at 4°C to 12°C without a significant reduction in their quality.

The traditional beef production in the South of Portugal is based on a discontinuous growth (DG) system that requires lower external inputs and could enhance meat quality and financial returns to cattle producers. This system allows farmers to take advantage of the bull’s compensatory growth when the pasture is abundant and finishes the cattle on concentrates for 2 to 3 months before slaughter. The fast gain rate before slaughter could be a valuable strategy to improve tenderness and to reduce its inconsistency in beef production. Therefore, the aim of this study was to evaluate the effects of production system (continuous growth (CG) v. DG) on longissimus thoracis muscle properties from Alentejana bulls. In total, 40 Alentejana male calves were allocated to two distinct feeding regimes: in the CG system, animals were fed concentrate plus hay and slaughtered at 18 months of age, whereas in the DG system, animals were fed on hay until 15 months of age and then fed the same diet provided to the CG group until 24 months of age. The DG system had a positive impact on meat tenderness (P<0.001) and global acceptability (P<0.001). DG bulls had greater fibre cross-sectional area (CSA) of glycolytic fibres (P<0.05) and relative area of the muscle (RA) occupied by type IIX fibres (P<0.01) and greater levels of α-actinin (P<0.05) and myosin light chain 2 (P<0.01) proteins, and pH24h (P<0.01) than CG bulls. The latter had greater CSA of type I (P<0.05) and type IIA (P<0.01) and greater RA of type IIA (P<0.05) and oxidative (P<0.05) than CG bulls. The compensatory growth production system had a positive impact on meat tenderness and global acceptability, overcoming the negative effects of slaughter of the bulls at a later age. The DG beef system could be a worthwhile strategy of beef production in Mediterranean areas due to the low-quality pasture in summer.

The objective of this study was to estimate the genetic parameters for thermoregulation traits and the relationships with performance of Large White lactating sows reared in a tropical humid climate. The thermoregulation traits were rectal temperature (RT), cutaneous temperature (CT) and respiratory rate (RR) during lactation measured in the afternoon (1200 h) and in the morning (0700 h). The production traits were sow’s average daily feed intake (ADFI), litter BW gain (LBWg) and sow’s proportion of BW change between farrowing and weaning (BWc). Complete data included 931 lactating performance on 329 Large White sows from the INRA experimental unit in Guadeloupe (French West Indies). Random regression models using linear spline functions were used for longitudinal data (RT, CT, RR and daily feed intake). Results showed that when ignoring values at the beginning and the end of lactation, the traits studied can be treated as the same trait throughout days of lactation, with fairly constant heritability and variance. However, largest heritabilities and genetic variances were estimated in mid-lactation. Heritability estimates on average performance during lactation were low to moderate for thermoregulation traits (0.35±0.09 for RT, 0.34±0.12 for CT and 0.39±0.13 for RR). Heritability estimates for production traits were 0.26±0.08 for ADFI, 0.20±0.07 for BWc and 0.31±0.09 for LBWg. Significant genetic correlations between thermoregulation traits and production traits were only obtained for ADFI and RR (0.35±0.12). From this study it can be concluded that thermoregulation traits are heritable, indicating that there are genetic differences in heat stress tolerance in lactating Large White sows.

There is increasing interest in the use of continuous housing systems for dairy cows, with various reasons put forward to advocate such systems. However, the welfare of dairy cows is typically perceived to be better within pasture-based systems, although such judgements are often not scientifically based. The aim of this review was to interrogate the existing scientific literature to compare the welfare, including health, of dairy cows in continuously housed and pasture-based systems. Although summarising existing work, knowledge gaps and directions for future research are also identified. The scope of the review is broad, examining relevant topics under three main headings; health, behaviour and physiology. Regarding health, cows on pasture-based systems had lower levels of lameness, hoof pathologies, hock lesions, mastitis, uterine disease and mortality compared with cows on continuously housed systems. Pasture access also had benefits for dairy cow behaviour, in terms of grazing, improved lying/resting times and lower levels of aggression. Moreover, when given the choice between pasture and indoor housing, cows showed an overall preference for pasture, particularly at night. However, the review highlighted the need for a deeper understanding of cow preference and behaviour. Potential areas for concern within pasture-based systems included physiological indicators of more severe negative energy balance, and in some situations, the potential for compromised welfare with exposure to unpredictable weather conditions. In summary, the results from this review highlight that there remain considerable animal welfare benefits from incorporating pasture access into dairy production systems.

The study determined the performance of equations to predict enteric methane (CH4) from beef cattle fed forage- and grain-based diets. Many equations are available to predict CH4 from beef cattle and the predictions vary substantially among equations. The aims were to (1) construct a database of CH4 emissions for beef cattle from published literature, and (2) identify the most precise and accurate extant CH4 prediction models for beef cattle fed diets varying in forage content. The database was comprised of treatment means of CH4 production from in vivo beef studies published from 2000 to 2015. Criteria to include data in the database were as follows: animal description, intakes, diet composition and CH4 production. In all, 54 published equations that predict CH4 production from diet composition were evaluated. Precision and accuracy of the equations were evaluated using the concordance correlation coefficient (rc), root mean square prediction error (RMSPE), model efficiency and analysis of errors. Equations were ranked using a combined index of the various statistical assessments based on principal component analysis. The final database contained 53 studies and 207 treatment means that were divided into two data sets: diets containing ⩾400 g/kg dry matter (DM) forage (n=116) and diets containing ⩽200 g/kg DM forage (n=42). Diets containing between ⩽400 and ⩾200 g/kg DM forage were not included in the analysis because of their limited numbers (n=6). Outliers, treatment means where feed was fed restrictively and diets with CH4 mitigation additives were omitted (n=43). Using the high-forage dataset the best-fit equations were the International Panel on Climate Change Tier 2 method, 3 equations for steers that considered gross energy intake (GEI) and body weight and an equation that considered dry matter intake and starch:neutral detergent fiber with rc ranging from 0.60 to 0.73 and RMSPE from 35.6 to 45.9 g/day. For the high-grain diets, the 5 best-fit equations considered intakes of metabolisable energy, cellulose, hemicellulose and fat, or for steers GEI and body weight, with rc ranging from 0.35 to 0.52 and RMSPE from 47.4 to 62.9 g/day. Ranking of extant CH4 prediction equations for their accuracy and precision differed with forage content of the diet. When used for cattle fed high-grain diets, extant CH4 prediction models were generally imprecise and lacked accuracy.

Development and long-term retention of replacement beef females in a semi-arid environment are of a major concern for extensive livestock producers. Furthermore, the demand of not only producing a thriving, healthy calf, but having sufficient milk to support that first calf is essential. To address this issue, we conducted a 3-year study measuring milk production and milk constituent yields in primiparous beef heifers (n=48; 16/year reared under two different feeding regimens) raising steer calves. Cows received 1.8 or 1.2 kg/day winter supplementation for ~80 day before parturition and their heifer calves were then randomly assigned to heifer development treatments that provided ad libitum (AL) or 80% (less than ad libitum (LAL)) of ad libitum feed post weaning. Heifers developed on the AL treatment also received 1.8 kg/day winter supplementation for life, whereas heifers developed on the LAL treatment received 1.2 kg/day winter supplementation for life. Milk production of primiparous cows was measured with a portable milking machine every other week from days 27 to 125 postpartum. Milk yield for the 125-day lactation period was calculated from area under the lactation curve approximated by trapezoidal summation. The ANOVA model included in utero winter nutrition, post-weaning heifer development treatment, year and their interaction. Heifers subjected to the AL treatment reached peak milk yield ~12.3 day later (P=0.02) than heifers receiving LAL treatment. In addition, an in utero nutrition×post-weaning heifer treatment×year interaction existed (P⩽0.04) for milk peak yield, average daily milk yield (kg/day) and nutrient composition (protein, lactose, fat, solids non-fat, g/day). These interactions manifest as changes in magnitude and rank across the 3 years of the study. Livestock production in extensive environments is subject to variations in seasonal precipitation patterns and quality and quantity of grazeable forage and these fluctuations have a large impact on milk yield. In summary, the gestational nutritional environment of a heifer’s mother may interact with the heifer’s nutrient consumption during post-weaning growth and the current year to trigger variation in year-to-year milk production.

The ability of live yeasts to modulate pig intestinal cell signals in response to infection with Escherichia coli F4ac (ETEC) has not been studied in-depth. The aim of this trial was to evaluate the effect of Saccharomyces cerevisiae CNCM I-4407 (Sc), supplied at different times, on the transcriptome profile of the jejunal mucosa of pigs 24 h after infection with ETEC. In total, 20 piglets selected to be ETEC-susceptible were weaned at 24 days of age (day 0) and allotted by litter to one of following groups: control (CO), CO+colistin (AB), CO+5×1010 colony-forming unit (CFU) Sc/kg feed, from day 0 (PR) and CO+5×1010 CFU Sc/kg feed from day 7 (CM). On day 7, the pigs were orally challenged with ETEC and were slaughtered 24 h later after blood sampling for haptoglobin (Hp) and C-reactive protein (CRP) determination. The jejunal mucosa was sampled (1) for morphometry; (2) for quantification of proliferation, apoptosis and zonula occludens (ZO-1); (3) to carry out the microarray analysis. A functional analysis was carried out using Gene Set Enrichment Analysis. The normalized enrichment score (NES) was calculated for each gene set, and statistical significance was defined when the False Discovery Rate % was <25 and P-values of NES were <0.05. The blood concentration of CRP and Hp, and the score for ZO-1 integrity on the jejunal villi did not differ between groups. The intestinal crypts were deeper in the AB (P=0.05) and the yeast groups (P<0.05) than in the CO group. Antibiotic treatment increased the number of mitotic cells in intestinal villi as compared with the control group (P<0.05). The PR group tended to increase the mitotic cells in villi and crypts and tended to reduce the cells in apoptosis as compared with the CM group. The transcriptome profiles of the AB and PR groups were similar. In both groups, the gene sets involved in mitosis and in mitochondria development ranked the highest, whereas in the CO group, the gene sets related to cell junction and anion channels were affected. In the CM group, the gene sets linked to the metabolic process, and transcription ranked the highest; a gene set linked with a negative effect on growth was also affected. In conclusion, the constant supplementation in the feed with the strain of yeast tested was effective in counteracting the detrimental effect of ETEC infection in susceptible pigs limits the early activation of the gene sets related to the impairment of the jejunal mucosa.

Machine vision-based monitoring of pig lying behaviour is a fast and non-intrusive approach that could be used to improve animal health and welfare. Four pens with 22 pigs in each were selected at a commercial pig farm and monitored for 15 days using top view cameras. Three thermal categories were selected relative to room setpoint temperature. An image processing technique based on Delaunay triangulation (DT) was utilized. Different lying patterns (close, normal and far) were defined regarding the perimeter of each DT triangle and the percentages of each lying pattern were obtained in each thermal category. A method using a multilayer perceptron (MLP) neural network, to automatically classify group lying behaviour of pigs into three thermal categories, was developed and tested for its feasibility. The DT features (mean value of perimeters, maximum and minimum length of sides of triangles) were calculated as inputs for the MLP classifier. The network was trained, validated and tested and the results revealed that MLP could classify lying features into the three thermal categories with high overall accuracy (95.6%). The technique indicates that a combination of image processing, MLP classification and mathematical modelling can be used as a precise method for quantifying pig lying behaviour in welfare investigations.

Two experiments were conducted to investigate the effects of dietary supplementation of bacteriophage cocktail, probiotics and a combination of these two supplements on performance and gut health of weanling pigs. In Experiment 1, 150 weaned piglets were randomly allotted to three treatments on the basis of BW. The dietary treatments included a basal diet supplemented with 0 (control), 1.0 and 1.5 g/kg bacteriophage cocktail. Pigs fed 1.0 and 1.5 g/kg bacteriophage product had greater (P<0.05) average daily gain (ADG), apparent total tract digestibility of dry matter from day 22 to 35, ileal Lactobacillus spp., villus height (duodenum and jejunum), and fewer coliforms (ileum) and Clostridium spp. (ileum). In Experiment 2, 200 weaned piglets were randomly allotted to four treatments. Dietary treatments included basal diet, basal diet supplemented with 3.0 g/kg fermented probiotic product (P), 1.0 g/kg bacteriophage cocktail (B) and combination of 1.0 g/kg bacteriophage cocktail and 3.0 g/kg fermented probiotic product. Pigs fed bacteriophage cocktail diets had greater (P<0.05) overall ADG, gain to feed ratio (G : F), fecal score from day 8 to day 21, and pigs fed bacteriophage cocktail diets had fewer coliforms (ileum) Clostridium spp. (ileum and cecum). Probiotics significantly increased G : F, colonization of Lactobacillus spp. in ileum. At day 35, bacteriophage treatment group showed greater (P<0.05) villus height of the duodenum, but a deeper crypt in duodenum. The present results indicate that the bacteriophage cocktail had a potential to enhance the performance and gut health of weanling pigs, however their combination with probiotics did not show an interaction.

Mitochondria plays an important role in the regulation of energy homeostasis. Moreover, mitochondrial biogenesis accompanies skeletal myogenesis, and we previously reported that maternal high-energy diet repressed skeletal myogenesis in pig fetuses. Therefore, the aim of this study was to evaluate the effects of moderately increased maternal energy intake on skeletal muscle mitochondrial biogenesis and function of the pig fetuses. Primiparous purebred Large White sows were allocated to a normal energy intake group (NE) as recommended by the National Research Council (NRC) and a high energy intake group (HE, 110% of NRC recommendations). On day 90 of gestation, fetal umbilical vein blood and longissimus (LM) muscle were collected. Results showed that the weight gain of sows fed HE diet was higher than NE sows on day 90 of gestation (P<0.05). Maternal HE diet increased fetal umbilical vein serum triglyceride and insulin concentrations (P<0.05), and tended to increase the homeostasis model assessment index (P=0.08). Furthermore, HE fetuses exhibited increased malondialdehyde concentration (P<0.05), and decreased activities of antioxidative enzymes (P<0.05) and intracellular NAD+ level (P<0.05) in LM muscle. These alterations in metabolic traits of HE fetuses were accompanied by reduced mitochondrial DNA amount (P<0.05) and down-regulated messenger RNA expression levels of genes responsible for mitochondrial biogenesis and function (P<0.05). Our results suggest that moderately increased energy supply during gestation decreases mitochondrial biogenesis, function and antioxidative capacity in skeletal muscle of pig fetuses.

We examined short- and long-term effects of high milking frequency (HMF) for the first 21 days of lactation. The study included 122 Israeli Holstein cows – 32 pregnant heifers, 40 cows in second lactation and 50 cows in >second lactation. Heifers were paired according to predicted transmitting ability and cows according to energy-corrected milk (ECM) production, age, days in milk and expected calving date. Thin cows (body condition score <2.75) were not included. One cow from each pair was arbitrarily allocated to a control group milked three times daily (3× milking cows) and the counterpart to an experimental group milked six times daily for the first 21 days of lactation and then three times daily for the rest of the lactation (6× milking cows). During the first 21 days of lactation, 6× milking cows produced 9.3 kg more milk (26.5%) and 7.16 kg more ECM (19%) than the 3× milking cows. The higher milk production persisted throughout the entire lactation (305 days), as reflected by treatment×age interaction showing higher milk production for the first and second (7%) but not >second lactation cows relative to their control counterparts (−0.37%); ECM production was also higher in 6× milking first and second lactation (7.6% and 5%, respectively) but not for >second lactation cows. Furthermore, HMF had long-lasting effects, expressed as significantly higher milk production through the succeeding lactation in the previous first lactation cows (10%); a tendency toward significance in the second lactation cows relative to the controls (4.7%), but a deleterious effect on the >second lactation cows, reflected by lower milk production (−5.25%) than in controls; similar patterns were found for the ECM. For the entire 305 days of lactation, fat and protein yields were higher for first and second lactation cows, whereas protein yield for >second lactation cows was lower in the 6× milking v. control group. Given that HMF during the first 21 days of first or second lactation increases milk and ECM yields throughout the concurrent and successive lactation with no adverse effect on energy balance, mastitis, metabolic diseases or reproduction, it seems to be economically beneficial. However, caution should be paid for >second lactation cows due to absence of significant effect in the entire of the first HMF applied lactation and the deleterious effect in the succeeding lactation.

The present work is aimed at evaluating the behaviour of Italian Heavy Draught Horse (IHDH) foals reared in semi-covered stables and fed two isoenergetic total mixed rations with different dietary protein levels (13.2% and 10.6% of CP on dry matter). The study was prompted by the restrictions for nitrate emissions in farms of the European Nitrate Directive. One suggested solution is to reduce dietary protein while maintaining normal performance and welfare, but there is a lack of literature in studies of horses. The behaviours of 20 foals of 437±60 kg of BW, aged 379±37 days and stabled in four pens by sex (S) and diet (D) were video recorded and analysed to build a suitable ethogram including 18 behaviours in six categories: ingestion, resting, maintenance, movement, social activities, other. The percentage of the daily time spent in each behavioural category and single behaviours was analysed via a single traits GLM including S, D and their interaction. Daily activity was consistent with existing literature: foals spent about 33% of the day in ingestion activities and 41% in resting, whereas social interactions constituted 8% of the time and individual maintenance <2%. Concerning diet, foals fed high protein spent more time in movement (19.62±0.73% of day v. 10.45±0.73% in low-protein (LP) foals; P⩽0.001), whereas the LP group increased resting (43.42±1.12% v. 38.02±1.12%; P⩽0.001). No stereotypies were found, and daily activity followed the typical values for draught breeds for foals in both dietary groups, a result that suggests the maintenance of well-being after dietary protein reduction. This result, together with the findings of a companion study showing no changes in growth performances of foals, showed that a reduction of CP in foal diet is reconcilable with the maintenance of performance and welfare.

Cattleyak (hybrid of cattle and yak) exhibit higher capability in adaptability and production than cattle and yak, while the infertility of F1 males greatly restricts the effective utilization of this hybrid and little progress has been made on investigating the mechanisms of the cattleyak infertility. Cattleyak individuals at three development stages (10, 12 and 14-month old) were sampled in this work and the isobaric tag for relative and absolute quantification method was employed to identify differences between their testicular proteomes. The proteomic analysis identified 318 proteins differentially expressed with significance at 12-month stage and 327 at 14-month compared with 10-month stage, respectively. Compared with the testicular proteome from 10-month cattleyak, the gene ontology (GO) annotations of the differentially expressed proteins at 12 months did not indicate significant differences from those at 14 months, which confirmed the histological observation that germ cell reduction was more obvious and spermatogenic arrest may become more serious in 12-month-old cattleyak. On the other hand, 56 differentially expressed proteins were coexpressed at 12 and 14-month stage compared with 10-month stage, in which 32 proteins were upregulated and 24 downregulated. GO analysis revealed that most of the differently expressed proteins were involved in the molecular function of catalytic activity, transporter activity, oxidoreductase activity and protein binding. Further analysis indicated that the differently expressed proteins including testis-expressed protein 101 precursor, RNA-binding motif protein, X chromosome, putative RNA-binding protein 3, heparin-binding proteins, tudor domain-containing protein 1, glutathione S-transferases (GSTA2, GSTP1), heat shock-related 70 kDa protein 2, estradiol 17-β-dehydrogenase11, 2,4-dienoyl-CoA reductase and peroxiredoxin-2 were possibly associated with testis development and spermatogenesis, which could be selected as candidate proteins in future study to examine the mechanisms of cattleyak infertility.

Using a meta-analysis of literature data, this study aimed to quantify the dry matter (DM) intake response to changes in diet composition, and milk responses (yield, milk component yields and milk composition) to changes in dietary net energy for lactation (NEL) and metabolizable protein (MP) in dairy cows. From all studies included in the database, 282 experiments (825 treatments) with experimentally induced changes in either NEL or MP content were kept for this analysis. These treatments covered a wide range of diet characteristics and therefore a large part of the plausible NEL and MP contents and supplies that can be expected in practical situations. The average MP and NEL contents were, respectively (mean±SD), 97±12 g/kg DM and 6.71±0.42 MJ/kg DM. On a daily supply basis, there were high between-experiment correlations for MP and NEL above maintenance. Therefore, supplies of MP and NEL above maintenance were, respectively, centred on MP supply for which MP efficiency into milk protein is 0.67, and NEL above maintenance supply for which the ratio of NEL milk/NEL above maintenance is 1.00 (centred variables were called MP67 and NEL100). The majority of the selected studies used groups of multiparous Holstein-Friesian cows in mid lactation, milked twice a day. Using a mixed model, between- and within-experiment variation was split to estimate DM intake and milk responses. The use of NEL100 and MP67 supplies substantially improved the accuracy of the prediction of milk yield and milk component yields responses with, on average, a 27% lower root mean square error (RMSE) relative to using dietary NEL and MP contents as predictors. For milk composition (g/kg), the average RMSE was only 3% lower on a supply basis compared with a concentration basis. Effects of NEL and MP supplies on milk yield and milk component yields responses were additive. Increasing NEL supply increases energy partitioning towards body reserve, whereas increasing MP supply increases the partition of energy towards milk. On a nitrogen basis, the marginal efficiency decreases with increasing MP supply from 0.34 at MP67=−400 g/day to 0.07 at MP67=300 g/day. This difference in MP67 supply, assuming reference energy level of NEL100=0, equates to a global nitrogen efficiency decrease from 0.82 to 0.58. The equations accurately describe DM intake response to change in dietary contents and milk responses to change in dietary supply and content of NEL and MP across a wide range of dietary compositions.

Dynamics of myofiber differentiation/maturation in porcine skeletal muscle is associated with domestication, breeding and rearing conditions. This study was aimed to comparatively elucidate the age-dependent myosin heavy chain (MyHC) isoform expression and transition pattern in domestic and wild pig (WP) skeletal muscle from birth until adulthood. Domestic pigs (DPs) of Large White breed raised in conventional production system were compared with WPs reared in a large hunting enclosure. Muscle samples for immuno/enzyme histochemistry were taken from the longissimus dorsi muscle within 24 h postmortem at 24 to 48 h, 21 to 23 days, 7 months and ~2 years postpartum. Based on the antibody reactivity to MyHCs (NCL-MHCs, A4.74, BF-F3) and succinate dehydrogenase activity, myofibers were classified into I, I/IIa, IIa, IIx and IIb types. In addition, foetal MyHC expression was determined with the use of F158.4C10 antibody. Maturation of the longissimus dorsi muscle in the WP was characterized by an accelerated transformation of the fast to slow MyHC during the first hours postpartum, followed by differentiation towards oxidative myofibers in which type I, IIa and IIx MyHCs predominated. In the DP, the transformation shifted towards glycolytic myofibers that expressed MyHC-IIb. The expression of foetal MyHC was higher in the DP than in the WP at 1 day of age, and the decline in the foetal MyHC during the first 3 weeks was more rapid in the WP than in the DP denoting an accelerated early postnatal muscle maturation in WP than DP piglets. All foetal MyHC-positive myofibers co-expressed IIa isoform, but not vice versa. The intense myofiber hypertrophy was evident from 3 weeks until 7 months of age. In this period, the myofiber cross-sectional area increased up to 10- and 20-fold in the WP and the DP, respectively. In the DP, the hypertrophy of all myofiber types was more pronounced than in the WP, particularly the hypertrophy of IIx and IIb myofibers. To summarize, the comparison between growing DP with wild ancestors showed that genetic selection and rearing conditions lead to substantial changes in the direction and intensity of postnatal MyHC transformation as evidenced by different proportion of individual myofiber types and differences in their hypertrophic potential.

A total of 120 Duroc×(Large White×Landrace) pigs, 50% barrows and 50% gilts, with 54.1±0.14 kg BW and 103±3 days of age, were used to study the effect of advancing the shift to a standard finisher feed from 100 to 90 and 80 kg BW on production performances and carcass and pork quality. Each of the six treatments (two sexes×three BWs at time of feeding shift) was replicated four times and the experimental unit was the pen (with five pigs for growth performance and carcass variables and three pigs for pork and fat traits). The grower (163 g CP and 9.5 g total Lys/kg) and the finisher diets (152 g CP and 7.9 g total Lys/kg) were based on maize, barley and vegetal protein concentrates, contained 13.39 MJ metabolizable energy/kg and were offered ad libitum through the trial. Pigs intended for dry-cured product elaboration were slaughtered at 170±3 days of age as average (124 and 115 kg BW for barrows and gilts, respectively). For the overall period, barrows ate more feed (P<0.001) and grew faster (P=0.03) than gilts. No effect of feed shift was observed on growth performances, although the average daily CP intake (P=0.01) and feeding costs (P=0.04) were reduced by advancing the transition to the finisher feed. Carcasses from barrows were heavier (P<0.001) and had wider backfat depth (P<0.001) than those from gilts but no significant differences were observed in the meat chemical composition. The feed change schedule did not modify carcass or meat traits. It is concluded that an early shift to the finisher feed (at 80 kg BW instead of 100 kg BW) might be an interesting strategy in pigs intended for dry-cured products because, although it neither increased body fatness nor improved pork quality, CP intake and feeding costs were reduced without impairment of growth performances. Results were similar for barrows and gilts.

The primary objective of this study was to examine the effects of different inclusion rates of dietary triticale replacing corn grain in starter rations of dairy calves on feed intake, average daily gain (ADG), feed efficiency, skeletal growth, fecal score, and selected blood and ruminal parameters. In all, 30 4-day-old Holstein calves (15 female and 15 male) were blocked by gender and birth weight, and then randomly allotted to three treatment groups (n=10 calves/treatment) and received either a corn-based diet without triticale (T0), or a diet containing 16% (T16) or 32% (T32) triticale (25% and 50% corn replaced by triticale, respectively) for 10 weeks. Calves were weaned on day 43 of study and remained on the study until day 70. During post-weaning period, calves fed T32 had the lowest starter intake (1.78 kg/day; P=0.02). In contrast, ADG was not affected in pre-weaning and overall periods, but calves fed T32 had a lower ADG (P=0.04) as compared with calves fed T0 in post-weaning period. No dietary effect was detected for feed efficiency. Dietary treatment did not affect heart girth and body length; however, height at wither and hip at weaning increased in calves fed triticale compared with T0. No detectable effects were observed in serum glucose and β-hydroxybutyrate. No difference was detected in blood urea nitrogen on day 35 either but on day 50 and day 70 the greatest concentration was recorded for calves fed T16. Compared with the control, ruminal ammonia concentration was increased for calves fed T32 (4.34 v. 7.50 mmol/l) and T16 (4.01 v. 8.12 mmol/l) on day 35 and day 50. No difference was detected in ruminal pH on day 35 or day 50; however, calves fed T32 had the lowest pH (6.11) at 70 days. No significant effect was detected in days scoured, respiratory score and general appearance. Under our experimental conditions, it appears that triticale at 16% dry matter (i.e. replacing corn grain up to 25%) in the starter diet does not have adverse effects on the performance and intake of calves. Therefore, substituting corn partially with triticale in calf starter diets may prove beneficial in places where corn is less abundant or its price is prohibitive. The low number of calves per treatment however may have limited the statistical power to detect significant differences among treatments, possibly affecting the results, which should be interpreted with caution.