Impact of litter size, supplementary milk replacer and housing on the body composition of piglets from hyper-prolific sows at weaning

Effects of sex on fat deposition through gut microbiota and short-chain fatty acids in weaned pigs

Nitrogen pollution resulting from excessive feed consumption poses a significant challenge for modern swine production. Precision nutrition technology seems to be an effective way to solve this problem; therefore, understanding the law of pig body composition deposition is a prerequisite. This study investigated the sex effects on growth performance, body composition, nutrient deposition, gut microbiota, and short-chain fatty acids (SCFA) in weaned piglets. Eighty weaned pigs were randomly allocated to 2 treatments according to the sex of pigs. An individual pig was considered as a treatment replicate. Six body weights (BW 5, 7, 11, 15, 20, and 25 kg) were chosen as experimental points; for each point 10 piglets close to the average BW (5 males and 5 females) were slaughtered, and there was one growth phase between each 2 BW points. Results indicated that the males had higher average daily gain (ADG) and average daily feed intake (ADFI) compared to the females (P < 0.05) at growth phases 15 to 20 kg BW and 20 to 25 kg BW. Meanwhile, males at 20 kg BW had higher body fat content than females (P < 0.10). Males showed a higher body fat (P < 0.05) deposition rate at phase 15 to 20 kg BW (P < 0.05) than females. For pigs at 20 kg BW, the relative abundance of RuminococcaceaeUCG-005, Clostridium, Christensenellaceae_R-7_group, and Peptostreptococcaceae was significantly increased in males (P < 0.05) but that of Bifidobacterium was decreased (P < 0.05). At 25 kg BW, the relative abundance of Ruminococcaceae_NK4A214_group, Fibrobacter, RuminococcaceaeUCG-009, Ralstonia, Klebsiel, and Christensenellaceae_R-7_group in males was higher when compared with females (P < 0.05). In terms of SCFA, females exhibited higher concentrations of propionate compared to males (P < 0.05). The results of the current study indicated that sex influenced fat deposition through changes in the composition of gut microbiota and the content of SCFA, which has significant implications for the realization of precision nutrition in modern swine production.

An insight into the temporal dynamics in the gut microbiome, metabolite signaling, immune response, and barrier function in suckling and weaned piglets under production conditions

Little information is available on age- and creep-feeding-related microbial and immune development in neonatal piglets. Therefore, we explored age- and gut-site-specific alterations in the microbiome, metabolites, histo-morphology, and expression of genes for microbial signaling, as well as immune and barrier function in suckling and newly weaned piglets that were receiving sow milk only or were additionally offered creep feed from day of life (DoL) 10. The experiment was conducted in two replicate batches. Creep feed intake was estimated at the litter level. Piglets were weaned on day 28 of life. Gastric and cecal digesta and jejunal and cecal tissue were collected on DoL 7, 14, 21, 28, 31, and 35 for microbial and metabolite composition, histomorphology, and gene expression. In total, results for 10 piglets (n = 5/sex) per dietary group (sow milk only versus additional creep feed) were obtained for each DoL. The creep feed intake was low at the beginning and only increased in the fourth week of life. Piglets that were fed creep feed had less lactate and acetate in gastric digesta on DoL 28 compared to piglets fed sow milk only (p < 0.05). Age mainly influenced the gastric and cecal bacteriome and cecal mycobiome composition during the suckling phase, whereas the effect of creep feeding was small. Weaning largely altered the microbial communities. For instance, it reduced gastric Lactobacillaceae and cecal Bacteroidaceae abundances and lowered lactate and short-chain fatty acid concentrations on DoL 31 (p < 0.05). Jejunal and cecal expression of genes related to microbial and metabolite signaling, and innate immunity showed age-related patterns that were highest on DoL 7 and declined until DoL 35 (p < 0.05). Weaning impaired barrier function and enhanced antimicrobial secretion by lowering the expression of tight junction proteins and stimulating goblet cell recruitment in the jejunum and cecum (p < 0.05). Results indicated that age-dependent alterations, programmed genetically and by the continuously changing gut microbiome, had a strong impact on the expression of genes for gut barrier function, integrity, innate immunity, and SCFA signaling, whereas creep feeding had little influence on the microbial and host response dynamics at the investigated gut sites.

Selected Nutrition and Management Strategies in Suckling Pigs to Improve Post-Weaning Outcomes

Weaning is a critical period in a pig's life. Piglets are confronted with abrupt changes to their physical and social environment, as well as management and nutritional changes. Weaning has always been associated with a growth check and is frequently accompanied by post-weaning diarrhoea in piglets. However, rapid increases in litter size in the last decade have increased within-litter piglet weight variation, with piglets now generally lighter at weaning, making the challenges associated with weaning even greater. Many interventions can be employed during the suckling period to ease the weaning transition for piglets. Pre-weaning strategies such as supervised farrowing (assistance with suckling and oxytocin provision), the provision of pain relief to sows around farrowing, split-suckling, early oral supplementation with glucose, bovine colostrum, faecal microbiota transplantation, feed additives and solid and liquid creep feeding (milk and liquid feed) have all been investigated. The objective of these strategies is to stimulate earlier maturation of the digestive tract, improve immunity, reduce latency to the first feed post-weaning and increase early post-weaning feed intake and growth. This review focuses in particular on: (1) pain relief provision to sows around farrowing, (2)split-suckling of piglets, (3) pre-weaning provision of supplementary milk and/or liquid feed, (4) other strategies to stimulate earlier enzyme production (e.g., enzyme supplementation), (5) other nutritional strategies to promote improved gut structure and function (e.g., L-glutamine supplementation), and (6) other strategies to modulate gut microbiota (e.g., probiotics and prebiotics). Correctly implementing these strategies can, not only increase post-weaning growth and reduce mortality, but also maximise lifetime growth in pigs.

Impact of liquid diet supplementation while suckling and weaning age on nutritional status, intestinal health, and immunity of piglets pre- and post-weaning

New strategies are needed to enhance piglets' robustness and proper functional development and maturation of piglets' intestine before weaning, to reduce the number of antibiotic treatments of diarrheic disorders in newly weaned piglets. It was hypothesized that a liquid nutritional supplement during the suckling period, and/or an increased weaning age, would beneficially impact piglets' gut health and enhance piglets' nutritional status before weaning. Further, it was hypothesized that a high intake of colostrum during the first 24 h after birth would be more advantageous for piglets' growth and robustness when compared to a low colostrum intake (CI). A 2 × 2 factorial design with two nutritional strategies (± supplementation with milk/feed, i.e., milk provided from day 2 shifted to wet feed at day 12 of age) and two weaning ages (days 24 vs. 35) was used. In total, 460 piglets from 24 sows were used for estimation of the individual CI after birth. Provision of the nutritional supplement and the increased weaning age improved the nutritional status of piglets' post-weaning assessed by their blood plasma concentration of albumin (P = 0.04), triglycerides (P = 0.004), and nonesterified fatty acids (P = 0.02). Piglets with high CI demonstrated improved nutritional status when compared to low CI (P = 0.04). Villous height and crypt depth were greater in piglets weaned at day 35 of age in contrast to day 24 of age (P < 0.001) irrespective of the nutritional intervention (P = 0.82). The concentration of branched-chain fatty acids in piglets' digesta was reduced in groups provided the nutritional supplement (P = 0.01), while total short-chain fatty acids were elevated at weaning in large intestinal digesta of piglets weaned at day 35 of age compared to piglets weaned at day 24 of age (P = 0.05). The weaning age in combination with the nutritional supplement had pronounced beneficial effect on gene expression of all investigated genes: interleukin-6, interleukin-10, nuclear factor kappa-beta, occludine, prostaglandin-endoperoxide synthase-2, tumor necrosis factor-alpha, and zonula occludens-1 (ZO-1) (P = 0.04). In conclusion, nutritional supplementation preweaning combined with increased weaning age could be considered as a strategy for improvement of the intestinal health, function, and maturation in piglets pre- and post-weaning, and a high CI enhanced piglets' robustness before weaning.

The Effect of Drenching (Very) Low Birth Weight Piglets with a Dense, Concentrated Milk Replacer at Farms with Differing Farrowing Management

Introducing hyperprolific sows has led to proportionally more (very) low birth weight ((V)LBW) piglets, accompanied by higher mortality. To improve the survival of (V)LBW piglets, drenching a dense milk replacer (DMR) could be applied. A first experiment evaluated the effect of drenching DMR (1 or 3 doses within 24 h after birth) to LBW ((mean litter birth weight - 1*SD) and weighing between 1 kg and 750 g) and VLBW piglets ((mean litter birth weight - 1.5*SD) and weighing less than 750 g). On days 1, 2, 3, 9, and two days post-weaning, body weight, growth, skin lesions, and mortality were monitored. No effect of DMR was observed on any of the parameters. In a second experiment, LBW piglets were supplemented with DMR (similarly to experiment 1) at two farms differing in the level of perinatal care. The same parameters were evaluated, and again none were affected by drenching DMR. Overall survival of the LBW piglets was significantly higher at the farm with high perinatal care. It can be concluded that good perinatal management is more effective in enhancing the survival of LBW piglets than drenching.

Developing a Reference Database for Typical Body and Organ Growth of the Artificially Reared Pig as a Biomedical Research Model

Objectives: The pig is a common model utilized to support substantiation of novel bioactive components in infant formula. However, reference ranges for outcomes to determine safety are unclear. Our objective was to use historical data to objectively define typical body and organ growth metrics of the domesticated pig in research. Methods: Twenty-two studies were compiled to assess typical growth of body and organ weights in young pigs. Metadata were organized to include milk replacer sources, bioactive components, sex, breed, source of herd, feeding regimen, and rearing environment. A combination of statistical models including simple linear regression and linear mixed effect models were used to assess typical growth patterns. Results: Over 18,000 data points from 786 animals were available. In general, minimal differences in the growth of pigs who were male and female, artificially- or sow-reared, or fed ad libitum- or by scheduled-feeding, were observed in the first 30 days of life (P > 0.05). A weight-for-age chart from reference pigs was developed to compare body weights of pigs demonstrating growth characterized as accelerated, typical, reduced, and failure to thrive to illustrate effects of dietary interventions. Distributions of relative brain, liver, and intestine weights (as % of total body weight) were similar between rearing environments and sexes. An alternative bivariate level approach was utilized for the analysis of organ weights. This approach revealed significant biologically-relevant insights into how deficient diets can affect organ weight that a univariate level assessment of weight distribution was unable to detect. Conclusions: Ultimately, these data can be used to better interpret whether bioactive ingredients tested in the pig model affect growth and development within typical reference values for pigs in the first 30 days of life.