This study aimed to evaluate the effect of using different floor types to accommodate growing and finishing beef cattle on lameness. In all, 80 dairy origin bulls were blocked according to live weight and breed into 20 groups, and randomly allocated within groups to one of four treatments. The floor types studied were fully slatted flooring throughout the entire experimental period (CS); fully slatted flooring covered with rubber strips throughout the entire experimental period (RS); fully slatted flooring during the growing period and then moved to a solid floor covered with straw bedding during the finishing period (CS-S) and fully slatted flooring during the growing period and then moved to fully slatted flooring covered with rubber strips during the finishing period (CS-RS). The total duration of the study was 204 days. The first 101 days was defined as the growing period, with the remainder of the study defined as the finishing period. During the growing period, there was a tendency for bulls accommodated on CS to have a higher locomotion score compared with those accommodated on RS (P=0.059). However, floor type had no significant effect on locomotion score during the finishing period. There was also no significant effect of floor type on digital dermatitis during both the growing or finishing period. Floor type had no significant effect on swelling at the leg joints at the end of the finishing period. Bulls accommodated on RS had the least probability of bruised soles during both the growing and finishing period (P<0.01). Growing bulls accommodated on CS had significantly greater front heel height net growth compared with those accommodated on RS (P<0.05). However, bulls accommodated on RS had a tendency to have greater front toe net growth compared with those accommodated on CS (P=0.087). Finishing bulls accommodated on CS-RS had the greatest front toe net growth (P<0.001). Heel height net growth was greatest in bulls accommodated on CS-S (P<0.001). Floor type had no significant effect on mean maximum hoof temperature during the growing period. Finishing bulls accommodated on CS-S had a significantly lower mean maximum hoof temperature compared with those accommodated on any other floor type (P<0.001). The study concluded that rubber flooring is a suitable alternative to fully slatted flooring, reducing the prevalence of bruised soles. Despite greater toe net growth in bulls accommodated on rubber flooring, there was no effect of floor type on locomotion score, suggesting that increased toe net growth does not adversely affect walking ability. In addition, although mean maximum hoof temperature was lowest in bulls accommodated on straw bedding, there was no evidence to suggest this is indicative of improved hoof health.

In the present study, calcium propionate (CaP) was used as feed additive in the diet of calves to investigate their effects on rumen fermentation and the development of rumen epithelium in calves. To elucidate the mechanism in which CaP improves development of calf rumen epithelium via stimulating the messenger RNA (mRNA) expression of G protein-coupled receptors, a total of 54 male Jersey calves (age=7±1 days, BW=23.1±1.2 kg) were randomly divided into three treatment groups: control without CaP supplementation (Con), 5% CaP supplementation (5% CaP) and 10% CaP supplementation (10% CaP). The experiment lasted 160 days and was divided into three feeding stages: Stage 1 (days 0 to 30), Stage 2 (days 31 to 90) and Stage 3 (days 91 to 160). Calcium propionate supplementation percentages were calculated on a dry matter basis. In total, six calves from each group were randomly selected and slaughtered on days 30, 90 and 160 at the conclusion of each experimental feeding stage. Rumen fermentation was improved with increasing concentration of CaP supplementation in calves through the first 30 days (Stage 1). No effects of CaP supplementation were observed on rumen fermentation in calves during Stage 2 (days 31 to 90). Supplementation with 5% CaP increased propionate concentration, but not acetate and butyrate in calves during Stage 3 (days 91 to 160). The rumen papillae length of calves in the 5% CaP supplementation group was greater than that of Con groups in calves after 160 days feeding. The mRNA expression of G protein-coupled receptor 41 (GPR41) and GPR43 supplemented with 5% CaP were greater than the control group and 10% CaP group in feeding 160 days calves. 5% CaP supplementation increased the mRNA expression of cyclin D1, whereas did not increase the mRNA expression of cyclin-dependent kinase 4 compared with the control group in feeding 160-day calves. These results indicate that propionate may act as a signaling molecule to improve rumen epithelium development through stimulating mRNA expression of GPR41 and GPR43.

Starter feeding is usually used in lamb production to improve rumen development and to facilitate the weaning process, but molecular mechanism of which is not well understood. Therefore, the objective of this study is to investigate the effect of starter feeding on the expression of ruminal epithelial genes involved in cell proliferation, apoptosis and metabolism in pre-weaned lambs. We selected eight pairs of 10-day-old lamb twins. One twin was fed ewe milk (M, n=8), while the other was fed ewe milk plus starter (M+S, n=8). The lambs were sacrificed at 56 days age. Results showed that the lambs fed M+S had lower pH in the rumen and a higher concentration of acetate, propionate, butyrate and total volatile fatty acid (VFA). Compared with the M group, the concentration of β-hydroxybutyric acid in plasma had an increased trend, and the concentration of IGF-1 in plasma had an decreased trend in the M+S group. The length, width and surface of rumen papillae increased in the M+S group compared with the M group; this was associated with increased cell layers in the stratum corneum, stratum granulosum and total epithelia. Messenger RNA (mRNA) expression of proliferative genes of cyclin A, cyclin D1 and cyclin-dependent kinase 2 in the ruminal epithelia of M+S lambs was increased compared with M only lambs. The mRNA expression of apoptosis genes of caspase-3, caspase-8, B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) in the M+S group was decreased compared with M group, but the ratio of Bcl-2 to Bax were not changed between the two groups. Expression of IGF-1 mRNA was decreased, but the mRNA expression of IGF-1 receptor was higher in ruminal epithelia in the M+S group. Furthermore, the mRNA expression of VFA absorption and metabolism genes of β-hydroxybutyrate dehydrogenase isoforms 1 and 3-hydroxy-3-methylglutaryl-CoA lyase had an increased trend in the M+S group than in the M group, but the mRNA expression of 3-hydroxy-3-methylglutaryl-CoA synthase isoform 1, monocarboxylate transporter isoform 1 and putative anion transporter isoform 1 had a decreased trend in the M+S group than in the M group. These results suggest that starter feeding increased proliferation and inhibited apoptosis of ruminal epithelial cells, and may promote the VFA metabolism in ruminal epithelium in pre-weaned lambs. These findings provide new insights into improving rumen development by nutritional intervention strategies in pre-weaned lambs.

Fertilization is an intricate cascade of events that irreversibly alter the participating male and female gamete and ultimately lead to the union of paternal and maternal genomes in the zygote. Fertilization starts with sperm capacitation within the oviductal sperm reservoir, followed by gamete recognition, sperm–zona pellucida interactions and sperm–oolemma adhesion and fusion, followed by sperm incorporation, oocyte activation, pronuclear development and embryo cleavage. At fertilization, bull spermatozoon loses its acrosome and plasma membrane components and contributes chromosomes, centriole, perinuclear theca proteins and regulatory RNAs to the zygote. While also incorporated in oocyte cytoplasm, structures of the sperm tail, including mitochondrial sheath, axoneme, fibrous sheath and outer dense fibers are degraded and recycled. The ability of some of these sperm contributed components to give rise to functional zygotic structures and properly induce embryonic development may vary between bulls, bearing on their reproductive performance, and on the fitness, health, fertility and production traits of their offspring. Proper functioning, recycling and remodeling of gamete structures at fertilization is aided by the ubiquitin–proteasome system (UPS), the universal substrate-specific protein recycling pathway present in bovine and other mammalian oocytes and spermatozoa. This review is focused on the aspects of UPS relevant to bovine fertilization and bull fertility.

Although the pain caused by castration of calves is a significant animal welfare issue for the beef industry, analgesia is not always used for this procedure, largely because of practical limitations associated with injectable forms of pain relief. Novel analgesic formulations have now been developed for livestock to allow topical and buccal administration, offering practical options to improve cattle welfare if shown to be effective. To assess the effects of topical anaesthetic (TA) and buccal meloxicam (BM) on average daily gain (ADG), behaviour and inflammation following surgical castration of beef calves, a total of 50 unweaned bull calves were randomly allocated to: (1) sham castration (SHAM, n=10); (2) surgical castration (C, n=10); (3) surgical castration with pre-operative buccal meloxicam (CBM, n=10); (4) surgical castration with post-operative topical anaesthetic (CTA, n=10); and (5) surgical castration with pre-operative buccal meloxicam and post-operative topical anaesthetic (CBMTA, n=10). Calves were recorded on video for 5 h following treatment and the frequency and duration of specific behaviours displayed by each animal was later observed for 5 min every hour (total of 25 min). Average daily gain was calculated 1, 2 and 6 days following treatment. Scrotal diameter measurements and photographs of wounds were collected from all castrated calves 1, 2 and 6 days following treatment to evaluate inflammation and wound healing. Infrared photographs were used to identify maximum scrotal temperature. Digital photographs were used to visually score wounds on a numerical rating scale of 1 to 5, with signs of inflammation increasing and signs of healing decreasing with progressive scores. Sham castration calves displayed significantly less, and C calves displayed significantly more foot stamps than all other calves (P=0.005). Observations on the duration of time that calves displayed a hypometric ‘stiff gait’ locomotion, indicated that SHAM calves tended to spend no time, C calves tended to spend the greatest time and all other calves tended to spend an intermediate time displaying this behaviour (P=0.06). Maximum scrotal temperatures were lower in CBM and CBMTA calves than C and CTA calves 2 days following treatment (P=0.004). There was no significant effect of treatment on ADG (P=0.7), scrotal diameter (P=0.09) or wound morphology score (P=0.5). These results suggest that TA and BM, alone or in combination, reduced pain and BM reduced inflammation following surgical castration of calves.

In ewe lambs, acceleration of growth and accumulation of both muscle and fat leads to earlier sexual maturity and better reproductive performance. The next stage in the development of this theme is to test whether these aspects of growth in young ewes affect milk production in their first lactation and the growth of their first progeny. We studied 75 young Merino ewes that had known phenotypic values for depth of eye muscle (EMD) and fat (FAT), and known Australian Sheep Breeding Values for post-weaning weight (PWT) and depths of eye muscle (PEMD) and fat (PFAT). They lambed for the first time at 1 year of age. Their lambs were weighed weekly from birth to weaning at 10 weeks to determine live weight gain and weaning weight. Progeny birth weight was positively associated with live weight gain and weaning weight (P<0.001). The PWT of the mothers was positively associated with birth weight (P<0.01), live weight gain and weaning weight of the progeny (P<0.05); however, these progeny traits were not influenced by EMD, FAT, PEMD, PFAT of the mothers (P>0.05). The PWT of the sire was positively associated with live weight gain (P<0.05) and weaning weight of the progeny (P<0.01). At around day 20 postpartum, we measured milk production and milk composition (fat, protein, lactose, total solids). Milk production was influenced positively by birth type (single or twin; P<0.05) and negatively by birth weight (P<0.05), but not by mother phenotype or genotype, sire genotype of the mother or the sex of the progeny (P>0.05). The concentrations of fat, protein, lactose and total solids in the milk were not affected by the phenotype or genotype of the mothers or of the sires of the mothers, or by the sex of the progeny (P>0.05). We conclude that selection of young Merino ewes for better growth, and more rapid accumulation of muscle and fat, will lead to progeny that are heavier at birth, grow faster and are heavier at weaning. Moreover, milk production and composition do not seem to be affected by the genetic merit of the mother for post-weaning live weight or PEMD or PFAT. Therefore, Merino ewes can lamb at 1 year of age without affecting the production objectives of the Merino sheep industry.

In ovo feeding (IOF) of l-arginine (Arg) can affect growth performance of broilers, but the response of IOF of Arg on breast muscle growth is unclear, and the mechanism involved in protein deposition remains unknown. Hense, this experiment was conducted to evaluate the effects of IOF of Arg on breast muscle growth and protein-deposited signalling in post-hatch broilers. A total of 720 fertile eggs were collected from 34-week-old Arbor Acres breeder hens and distributed to three treatments: (1) non-injected control group; (2) 7.5 g/l (w/v) NaCl diluent-injected control group; (3) 0.6 mg Arg/egg solution-injected group. At 17.5 days of incubation, fertile eggs were injected 0.6 ml solutions into the amnion of the injected groups. Upon hatching, 80 male chicks were randomly assigned to eight replicates of 10 birds each and fed ad libitum for 21 days. The results indicated that IOF of Arg increased relative breast muscle weight compared with those of control groups at hatch, 3-, 7- and 21-day post-hatch (P<0.05). In the Arg-injected group, the plasma total protein and albumen concentrations were higher at 7- and 21-day post-hatch than those of control groups (P<0.05). The alanine aminotransferase activity in Arg group was higher at hatch than that of control groups (P<0.05). The levels of triiodothyronine at four time points and thyroxine hormones at hatch, 7- and 21-day post-hatch in Arg group were higher than those of control groups (P<0.05). In addition, IOF of Arg increased the amino acid concentrations of breast muscle at hatch, 7- and 21-day post-hatch (P<0.05). In ovo feeding of Arg also enhanced mammalian target of rapamycin, ribosomal protein S6 kinase-1 and eIF4E-bindingprotein-1 messenger RNA expression levels at hatch compared with those of control groups (P<0.05). It was concluded that IOF of Arg treatment improved breast muscle growth, which might be associated with the enhancement of protein deposition.

The technology available to assess sperm population characteristics has advanced greatly in recent years. Large artificial insemination (AI) organizations that sell bovine semen utilize many of these technologies not only for novel research purposes, but also to make decisions regarding whether to sell or discard the product. Within an AI organization, the acquisition, interpretation and utilization of semen quality data is often performed by a quality control department. In general, quality control decisions regarding semen sales are often founded on the linkages established between semen quality and field fertility. Although no one individual sperm bioassay has been successful in predicting sire fertility, many correlations to various in vivo fertility measures have been reported. The most powerful techniques currently available to evaluate semen are high-throughput and include computer-assisted sperm analysis and various flow cytometric analyses that quantify attributes of fluorescently stained cells. However, all techniques measuring biological parameters are subject to the principles of precision, accuracy and repeatability. Understanding the limitations of repeatability in laboratory analyses is important in a quality control and quality assurance program. Hence, AI organizations that acquire sizeable data sets pertaining to sperm quality and sire fertility are well-positioned to examine and comment on data collection and interpretation. This is especially true for sire fertility, where the population of AI sires has been highly selected for fertility. In the December 2017 sire conception rate report by the Council on Dairy Cattle Breeding, 93% of all Holstein sires (n=2062) possessed fertility deviations within 3% of the breed average. Regardless of the reporting system, estimates of sire fertility should be based on an appropriate number of services per sire. Many users impose unrealistic expectations of the predictive value of these assessments due to a lack of understanding for the inherent lack of precision in binomial data gathered from field sources. Basic statistical principles warn us of the importance of experimental design, balanced treatments, sampling bias, appropriate models and appropriate interpretation of results with consideration for sample size and statistical power. Overall, this review seeks to describe and connect the use of sperm in vitro bioassays, the reporting of AI sire fertility, and the management decisions surrounding the implementation of a semen quality control program.

Protocols designed for the adipogenic differentiation of human and mouse cells are commonly used for inducing the adipogenesis of bovine stromal vascular cells. However, likely due to metabolic differences between ruminant and non-ruminant animals, these methods result in only few cells undergoing complete adipogenesis with minimal lipid droplet accumulation. Here, we discuss the development of an adipogenic differentiation protocol for bovine primary cells through a three-dimensional spheroid culture. Stromal vascular cells derived from bovine intramuscular fat were isolated and stored in liquid nitrogen before culturing. Cells were cultured in hanging drops for 3 days to allow for the formation of spherical structures. The spheroids were then transferred to cell culture plates with endothelial basal medium-2 for 3 days and in Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with a standard adipogenic cocktail for 3 additional days, which were then allowed to fully differentiate for 3 days in DMEM supplemented with insulin. Compared with conventional two-dimensional culture, cells in a three-dimensional spheroid culture system had higher adipogenic gene expression and consequently contained more adipocytes with larger lipid droplets. In addition, endothelial induction of spheroids prior to adipogenic differentiation is essential for efficient induction of adipogenesis of bovine stromal vascular cells, mimicking in vivo adipose development. In summary, the newly developed three-dimensional spheroid culture method is an efficient way to induce adipogenic differentiation and study adipose development of cells derived from ruminant animals, which also can be used for studying the role of angiogenesis in adipose development.

Genetic improvement, without control of inbreeding, can go to loss of genetic variability, reducing the potential for genetic gains in the domestic populations. The aim of this study was to analyze the population structure and the inbreeding depression in Campolina horses. Phenotype information from 43 465 individuals was analyzed, data provided by the Campolina Breeders Association. A pedigree file containing 107 951 horses was used to connected the phenotyped individuals. The inbreeding coefficient was performed by use of the diagonal of the relationship matrix and the genealogical parameters were computed using proper softwares. The effective population size was estimated based on the rate of inbreeding and census information, and the stratification of the population was verified by the average relationship coefficient between animals born in different regions of Brazil. The effects of inbreeding on morphological traits were made by the use of inbreeding coefficient as a covariate in the model of random regression. The inbreeding coefficient increased from 1990 on, impacting effective population size and, consequently, shrinking genetic variability. The paternal inbreeding was greater than maternal, which may be attributed to the preference for inbred animals in reproduction. The average genetic relationship coefficient of animals born in different states was lower than individuals born within the same state. The increase in the inbreeding coefficient was negatively associated with all studied traits, showing the importance to avoid genetic losses in the long term. Although results do not indicate a severe narrowing of the population until the present date, the average relationship coefficient shows signs of increase, which could cause a drastic reduction in genetic variability if inbred mating is not successfully controlled in the Campolina horse population.

Diet manipulation and genetic selection are two important mitigation strategies for reducing enteric methane (CH4) emissions from ruminant livestock. The aim of this study was to assess whether the diurnal pattern of CH4 emissions from individual dairy cows changes over time when cows are fed on diets varying in forage composition. Emissions of CH4 from 36 cows were measured during milking in an automatic (robotic) milking station in three consecutive feeding periods, for a total of 84 days. In Periods 1 and 2, the 36 cows were fed a high-forage partial mixed ration (PMR) containing 75% forage, with either a high grass silage or high maize silage content. In Period 3, cows were fed a commercial PMR containing 69% forage. Cows were offered PMR ad libitum plus concentrates during milking and CH4 emitted by individual cows was sampled during 8662 milkings. A linear mixed model was used to assess differences among cows, feeding periods and time of day. Considerable variation was observed among cows in daily mean and diurnal patterns of CH4 emissions. On average, cows produced less CH4 when fed on the commercial PMR in feeding Period 3 than when the same cows were fed on high-forage diets in feeding Periods 1 and 2. The average diurnal pattern for CH4 emissions did not significantly change between feeding periods and as lactation progressed. Emissions of CH4 were positively associated with dry matter (DM) intake and forage DM intake. It is concluded that if the management of feed allocation remains constant then the diurnal pattern of CH4 emissions from dairy cows will not necessarily alter over time. A change in diet composition may bring about an increase or decrease in absolute emissions over a 24-h period without significantly changing the diurnal pattern unless management of feed allocation changes. These findings are important for CH4 monitoring techniques that involve taking measurements over short periods within a day rather than complete 24-h observations.

The effect of botanical diversity on supply of polyunsaturated fatty acids (PUFA) to ruminants in vitro, and the fatty acid (FA) composition of muscle in lambs was investigated. Six plant species, commonly grown as part of UK herbal ley mixtures (Trifolium pratense, Lotus corniculatus, Achillea millefolium, Centaurea nigra, Plantago lanceolata and Prunella vulgaris), were assessed for FA profile, and in vitro biohydrogenation of constituent PUFA, to estimate intestinal supply of PUFA available for absorption by ruminants. Modelling the in vitro data suggested that L. corniculatus and P. vulgaris had the greatest potential to increase 18:3n-3 supply to ruminants, having the highest amounts escaping in vitro biohydrogenation. Biodiverse pastures were established using the six selected species, under-sown in a perennial ryegrass-based sward. Lambs were grazed (~50 days) on biodiverse or control pastures and the effects on the FA composition of musculus longissimus thoracis (lean and subcutaneous fat) and musculus semimembranosus (lean) were determined. Biodiverse pasture increased 18:2n-6 and 18:3n-3 contents of m. semimembranosus (+14.8 and +7.2 mg/100 g tissue, respectively) and the subcutaneous fat of m. longissimus thoracis (+158 and +166 mg/100 g tissue, respectively) relative to feeding a perennial ryegrass pasture. However, there was no effect on total concentrations of saturated FA in the tissues studied. It was concluded that enhancing biodiversity had a positive impact on muscle FA profile reflected by increased levels of total PUFA.

Previous studies showed that butyrate played benefit roles in the health and metabolism of animals. However, little information on the effects of butyrate on the metabolism of piglets at the extraintestinal level is available. The present study investigated transcriptomic and metabolomic responses in the livers of pigs to evaluate the effects of intravenous sodium butyrate (SB) on the body’s metabolism at the extraintestinal level. A total of 12 Duroc×Landrace×Large White growing barrows (60 days of age) fitted with jugular vein cannula were randomly allocated to either the SB group or the control (CO) group. Pigs in the SB group were intravenously infused with 10 ml SB (200 mmol/l) for 7 days, whereas pigs in the CO group were treated with the same amount of saline. The livers of pigs were collected for gene expression and metabolome analyses. The RNA sequencing (RNA-Seq) analysis showed that the mRNA expression of Acyl-CoA synthetase long-chain family member 1 (ACSL1), carnitine palmitoyltransferase 1A (CPT1A), acetyl-CoA acyltransferase 2 (ACAA2) and phosphoenolpyruvate carboxykinase 1 (PCK1) were downregulated (Q<0.05), whereas fatty acid binding protein 1 (FABP1) and cytochrome P450 family 7 subfamily A member 1 (CYP7A1) were upregulated (P<0.05) by SB treatment, indicating a decrease in fatty acid oxidation and gluconeogenesis and an increase in fatty acid transportation and cholesterol metabolism. Gas chromatography-mass spectrometry analysis showed that raffinose was enriched in the SB group compared with the CO group, indicating a decrease in metabolism of galactose. Moreover, SB treatment significantly decreased the concentration of blood cholesterol. The results suggest that a short-term intravenous infusion of SB could modulate hepatic lipid metabolism by decreasing fatty acid oxidation and increasing fatty acid transportation and cholesterol metabolism.

Factors influencing early development such as birth weight, nest competition, and the diet received during rearing have been proposed as elements conditioning the future reproductive performance of European rabbit (Oryctolagus cuniculus) females. To evaluate their effects, we followed the life of 1513 females from birth to time of death, culling or censoring (animals alive at a fixed date). Between 0 and 63 days of age 353 females died. From the remaining 1160 females, 864 were chosen based on their birth weight to be transferred from the selection to the production farm. At this farm, 431 females received the control diet (184 g of CP, 381 g of NDF and 11.8 MJ of DE per kg DM), while the other 433 received the fibrous diet (134 g of CP, 436 g of NDF and 10.0 MJ of DE per kg DM). Throughout the rearing period, we checked for the individual live weight and body condition (perirenal fat thickness) at first artificial insemination. Reproductive lifespan was defined as the number of days between the first parturition and the time of death, culling or censoring. Birth weight affected the survival of newborn females during lactation and the presence of a milk spot at birth (related to nest competition) increased the survivability of newborns weighing <45 g (P<0.001). Rearing diet altered the growth curve of females and their body condition at first insemination. The diet also altered the relative risk of death during the rearing period, which was lower among females fed on the fibrous diet (−12.5%; P<0.001). Therefore, a higher number of females fed with this diet reached their reproductive life, directly affecting the productivity measured per housed female. Fatter females at first insemination had smaller litter sizes and a higher risk of being culled than lean ones (P<0.05). In general, the fibrous diet reduced the risk of leaving the herd at early rearing, and both birth weight and perirenal fat thickness affected female’s reproductive lifespan. An excess of fat (positive change in one unit of perirenal fat) at their first insemination represented an increased the risk of death or elimination of 13%.

Artificial insemination has been a landmark procedure in improving animal agriculture over the past 150 years. The utility of artificial insemination has facilitated a rapid improvement in animal genetics across agricultural species, leading to improvements of growth, health and productivity in poultry, swine, equine and cattle species. The utility of artificial insemination, as with all assisted reproductive technologies side-steps thousands of years of evolution that has led to the development of physiological systems to ensure the transmission of genetics from generation to generation. The perceived manipulation of these physiological systems as a consequence of assisted reproduction are points of interest in which research could potentially improve the success of these technologies. Indeed, seminal fluid is either removed or substantially diluted when semen is prepared for artificial insemination in domestic species. Although seminal fluid is not a requirement for pregnancy, could the removal of seminal fluid from the ejaculate have negative consequences on reproductive outcomes that could be improved to further the economic benefit of artificial insemination? One such potential influence of seminal fluid on reproduction stems from the question; how does the allogeneic foetus survive gestation in the face of the maternal immune system? Observation of the maternal immune system during pregnancy has noted maternal immune tolerance to paternal-specific antigens; a mechanism by which the maternal immune system tolerates specific paternal antigens expressed on the foetus. In species like human or rodent, implantation occurs days after fertilisation and as such the mechanisms to establish antigen-specific tolerance must be initiated very early during pregnancy. We and others propose that these mechanisms are initiated at the time of insemination when paternal antigens are first introduced to the maternal immune system. It is unclear whether such mechanisms would also be involved in domestic species, such as cattle, where implantation occurs weeks later in gestation. A new paradigm detailing the importance of paternal–maternal communication at the time of insemination is becoming evident as it relates to maternal tolerance to foetal antigen and ultimately pregnancy success.

Weaning of piglets is associated with important changes in gut structure and function resulting from stressful events such as separation from the sow, moving to a new facility and dietary transition from a liquid to a solid feed. This may result in post-weaning diarrhoea and a decrease in feed intake and growth. In humans, the cyanobacterium Spirulina platensis (SP) and the freshwater microalga Chlorella vulgaris (CV) are known for their beneficial health effects. This study aimed to determine the effects of early oral administration of Spirulina and Chlorella in piglets on mucosal architecture and cytokine expression in the intestine around weaning, and consequences on growth performance and diarrhoea incidence. The experiment was conducted on 108 suckling piglets of 14 days of age (initial BW=4.9±0.7 kg) and weaned at 28 days of age (day 0). Animals received orally 385 mg/kg BW per day of SP or CV, or water (negative control (NC)) during 4 weeks from day −14 to day 14 and their growth performance was measured daily. After weaning, growth, feed intake and diarrhoea incidence were measured daily. Intestinal morphology and functionality were assessed at day −1, day 2, and day 14. During the suckling period, average daily gain (ADG) in SP piglets was higher, resulting in a higher weaning BW compared to NC and CV piglets (P<0.05). No significant difference between treatments was observed for ADG, average daily feed intake, and gain to feed (G : F) ratio after weaning, but the extent of growth retardation after weaning was the lowest in piglets supplemented with Chlorella (P<0.01). Supplementation with Spirulina reduced diarrhoea incidence by 50% from day 0 to day 14 (P<0.05). Mucosal architecture at the jejunum was unaffected by Spirulina or Chlorella administration (P>0.10). Shorter ileal villi were measured in SP and CV piglets than in NC piglets (P<0.05). Cytokine expression did not differ between treatments in response to weaning. At day 14, IL-8 expression in the ileum was higher in SP piglets, while IL-1β expression in the jejunum was higher in CV piglets (P<0.05). This study shows that Spirulina administration around weaning alleviates diarrhoea in weaned piglets, without marked modulation of local inflammation.

The aim of this experiment was to study the effect of total replacement of oat hay by rosemary distillation residues (RR) on growth, carcass characteristics and meat quality of Barbarine lambs. A total of 21 lambs were divided into three groups. The control group (C) was offered 600 g of oat hay; the RR87 and RR60 groups received 600 g of pellets containing 87% and 60% of RR, respectively. The CP content was 9% and 14% for RR87 and RR60, respectively. All animals were supplemented by 600 g of concentrate. After 77 days of fattening, lambs were slaughtered. The DM and CP intakes were significantly increased with RR diets. The average daily gain was higher (P<0.001), while the feed conversion rate was lower for RR60 and RR87 than C group. The dressing percentage was similar for all groups. The tissular (muscle, fat and bone) and the regional (leg, shoulder, etc.) carcass composition did not differ among groups. The bony organs and gut weights were similar among groups, while functional ones (skin, liver, kidney and testicles) were significantly heavier for both RR groups than control. The ultimate pH, water cooking loss and color variables were similar among groups and the chemical composition (protein, fat, myoglobin, collagen and iron) did not differ also among groups. These results revealed the opportunity of RR use in fattening lambs without adverse effects on carcass and meat characteristics. Moreover, 9% CP in RR pellets are enough given the same growth performance recorded as that of RR with 14% CP.