Porcine Digestible Peptides (PDP) in Weanling Diets Regulates the Expression of Genes Involved in Gut Barrier Function, Immune Response and Nutrient Transport in Nursery Pigs

Supplementing infant milk formula with a multi-strain synbiotic and osteopontin enhances colonic microbial colonization and modifies jejunal gene expression in lactating piglets

A total of ninety-six weaned piglets were assigned to four dietary treatments in a 2 × 2 design. The treatments included: a standard milk formula (CTR); CTR + probiotics (6.4 × 108 cfu L-1Bifidobacterium longum subsp. infantis CECT 7210 and 1.1 × 108 cfu L-1Lactobacillus rhamnosus NH001) + prebiotics (galacto-oligosaccharides 4.36 g L-1 and human-milk-oligosaccharide 0.54 g L-1) (SYN); CTR + osteopontin (0.43 g L-1) (OPN); and CTR + SYN + OPN (CON). Daily records including feed intake, body weight, and clinical signs, were maintained throughout the 15-day trial. At the end of the study samples from blood, digestive content, and gut tissues were collected to determine serum TNF-α, intestinal fermentative activity (SCFA and ammonia), colonic microbiota (16S rRNA Illumina-MiSeq), histomorphology, and jejunal gene expression (Open-Array). No statistical differences were found in weight gain; however, the animals supplemented with osteopontin exhibited higher feed intake. In terms of clinical signs, synbiotic supplementation led to a shorter duration of diarrhoea episodes. Regarding gut health, the sequenced faecal microbiota revealed better control of potentially dysbiotic bacteria with the CON diet at day 15. In the colon compartment, a significant increase in SCFA concentration, a decrease in ammonia concentration, and a significant decrease in intraepithelial lymphocyte counts were particularly observed in CON animals. The supplemented diets were also associated with modified jejunal gene expression. The synbiotic combination was characterized by the upregulation of genes related to intestinal maturation (ALPI, SI) and nutrient transport (SLC13A1, SLC15A1, SLC5A1, SLC7A8), and the downregulation of genes related to the response to pathogens (GBP1, IDO, TLR4) or the inflammatory response (IDO, IL-1β, TGF-β1). Osteopontin promoted the upregulation of a digestive function gene (GCG). Correlational analysis between the microbiota population and various intestinal environmental factors (SCFA concentration, histology, and gene expression) proposes mechanisms of communication between the gut microbiota and the host. In summary, these results suggest an improvement in the colonic colonization process and a better modulation of the immune response when milk formula is supplemented with the tested synbiotic combined with osteopontin, benefiting from a synergistic effect.

Porcine digestible peptides as alternative protein source in weaner diets: effects on performance and systemic cytokine profile in pigs followed from weaning to slaughter

Porcine digestible peptides (PDP) are high-quality hydrolysed proteins obtained from porcine intestinal mucosa as a by-product of the heparin manufacturing process. PDP contain bioactive peptides and are used as alternative protein sources in several animal species, including pigs. We aimed to explore the (carry-over) effects of feeding PDP to weaned piglets on performance and systemic cytokine levels of pigs followed until slaughter. A total of 192 piglets were allocated to one of two dietary treatments: control (CON) or PDP weaner diets. PDP was included at 5.0% until day 13 post-weaning at the expense of skimmed milk powder and partial replacement of soybean meal, and at 2.5% between days 13 and 34 post-weaning at the expense of soy protein concentrate. Grower-finishers were fed commercial diets according to a 3-phase feeding scheme until slaughter, when carcass traits were determined. Six pigs were housed per weaner pen and eight per grower-finisher pen with 16 and 10 pens per treatment, respectively. Pigs were weighed at the start and at the end of each phase, and feed intake was recorded. Faecal consistency was recorded twice a week in the weaner facility. Ten pigs per treatment were sampled for blood at days 13, 34 and 69 post-weaning. We found that PDP-fed piglets had a higher feed intake in the first two weeks post-weaning compared to CON-fed piglets (+32 g/pig per day; P = 0.02). Moreover, piglets in the PDP group showed improved feed conversion between days 13 and 34 versus the CON group (1.36 vs 1.43; P = 0.03). Piglets that were fed with PDP in the weaner diets tended to grow faster in the grower-finisher period (+32 g/pig per day; P = 0.07), tended to reach slaughter age earlier (129.9 vs 131.5 days; P = 0.07) and had a lower dressing percentage at slaughter (76.3 vs 76.7%, P = 0.045) than piglets previously fed with CON. Additionally, PDP-fed piglets showed higher serum levels of pro-inflammatory cytokines interleukin (IL)-12 (P = 0.02), tumour necrosis factor-alpha (P = 0.02), interferon-gamma (P = 0.03) and IL-8 (at day 34 post-weaning, P = 0.06) as well as anti-inflammatory cytokines transforming growth factor-beta (P = 0.02), IL-4 (P = 0.04) and IL-10 (at day 34 post-weaning, P = 0.02). No significant differences among dietary treatments were observed regarding faecal consistency of weaned piglets and carcass weight, lean meat percentage, muscle depth, and back fat thickness at slaughter. We conclude that feeding PDP, as an alternative to conventional milk and soy protein sources, showed positive effects on pig performance, not only during the provisioning period but also thereafter into the grower-finisher phase.

How copper can impact pig growth: comparing the effect of copper sulfate and monovalent copper oxide on oxidative status, inflammation, gene abundance, and microbial modulation as potential mechanisms of action

The beneficial effect of elevated concentrations of copper (Cu) on growth performance of pigs has been already demonstrated; however, their mechanism of action is not fully discovered. The objective of the present experiment was to investigate the effects of including Cu from copper sulfate (CuSO₄) or monovalent copper oxide (Cu₂O) in the diet of growing pigs on oxidative stress, inflammation, gene abundance, and microbial modulation. We used 120 pigs with initial body weight (BW) of 11.5 ± 0.98 kg in 2 blocks of 60 pigs, 3 dietary treatments, 5 pigs per pen, and 4 replicate pens per treatment within each block for a total of 8 pens per treatment. Dietary treatments included the negative control (NC) diet containing 20 mg Cu/kg and 2 diets in which 250 mg Cu/kg from CuSO₄ or Cu₂O was added to the NC. On day 28, serum samples were collected from one pig per pen and this pig was then euthanized to obtain liver samples for the analysis of oxidative stress markers (Cu/Zn superoxide dismutase, glutathione peroxidase, and malondialdehyde, MDA). Serum samples were analyzed for cytokines. Jejunum tissue and colon content were collected and used for transcriptomic analyses and microbial characterization, respectively. Results indicated that there were greater (P < 0.05) MDA levels in the liver of pigs fed the diet with 250 mg/kg CuSO₄ than in pigs fed the other diets. The serum concentration of tumor necrosis factor-alpha was greater (P < 0.05) in pigs fed diets containing CuSO₄ compared with pigs fed the NC diet or the diet with 250 mg Cu/kg from Cu₂O. Pigs fed diets containing CuSO₄ or Cu₂O had a greater (P < 0.05) abundance of genes related to the intestinal barrier function and nutrient transport, but a lower (P < 0.05) abundance of pro-inflammatory genes compared with pigs fed the NC diet. Supplementing diets with CuSO₄ or Cu₂O also increased (P < 0.05) the abundance of Lachnospiraceae and Peptostreptococcaceae families and reduced (P < 0.05) the abundance of the Rikenellaceae family, Campylobacter, and Streptococcus genera in the colon of pigs. In conclusion, adding 250 mg/kg of Cu from CuSO₄ or Cu₂O regulates genes abundance in charge of the immune system and growth, and promotes changes in the intestinal microbiota; however, Cu₂O induces less systemic oxidation and inflammation compared with CuSO₄.

Understanding host-microbiota interactions in the commercial piglet around weaning

Weaning is a critical period in the life of pigs with repercussions on their health and welfare and on the economy of the swine industry. This study aimed to assess the effect of the commercial early weaning on gut microbiota, intestinal gene expression and serum metabolomic response via an integrated-omic approach combining 16S rRNA gene sequencing, the OpenArray gene expression technology and ¹H-NMR spectroscopy. Fourteen piglets from different litters were sampled for blood, jejunum tissue and caecal content two days before (− 2d), and three days after (+ 3d) weaning. A clearly differential ordination of caecal microbiota was observed. Higher abundances of Roseburia, Ruminococcus, Coprococcus, Dorea and Lachnospira genera in weaned piglets compared to prior to weaning showed the quick microbial changes of the piglets’ gut microbiota. Downregulation of OCLN, CLDN4, MUC2, MUC13, SLC15A1 and SLC13A1 genes, also evidenced the negative impact of weaning on gut barrier and digestive functions. Metabolomic approach pinpointed significant decreases in choline, LDL, triglycerides, fatty acids, alanine and isoleucine and increases in 3-hydroxybutyrate after weaning. Moreover, the correlation between microbiota and metabolome datasets revealed the existence of metabolic clusters interrelated to different bacterial clusters. Our results demonstrate the impact of weaning stress on the piglet and give insights regarding the associations between gut microbiota and the animal gene activity and metabolic response.

Phytogenic Compounds Supplemented to Gestating Hyperprolific Sows Affects the Gut Health-Related Gene Expression and Histological Responses in Neonate Piglets

This research aims to determine whether a specific blend of phytogenic compounds (BPC) supplemented in gestating hyperprolific sow diets can promote prenatal maternal effects in terms of piglet gut function and morphology. Twenty-eight (Landrace × Yorkshire) gilts and sows (parity 0 to 7) were randomly distributed by parity number and body weight into two dietary treatments: unsupplemented Control (CON) (n = 14) or CON diet supplemented with 1 g/kg feed of BPC during gestation (n = 14). The BPC supplementation during gestation of sows downregulated the neonate piglets' jejunal genes involved in oxidation (SOD2) and nutrient transport (SLC16A1/MCT1, SLC11A2/DMT1, and SLC39A/ZIP4), while IFNG and CLDN4 related to immune response and barrier function, respectively, were upregulated (q < 0.10). In addition, the jejunal villus height and the ratio of the villus height to crypt depth tended to increase (p < 0.10), while goblet cell volume density was higher (p < 0.05) in BPC compared to CON. In conclusion, dietary supplementation of BPC in gestating diets for hyperprolific sows influences neonatal histomorphology and expression of genes related to the intestinal function and health.