Mesobiliverdin IXα-enriched microalgae feed additive eliminates reliance on antibiotic tylosin to promote intestinal health of weaning piglets.

Weaning is a critical period in raising pigs. Novel animal feed additives that promote gut health and regulate immune function of piglets without antibiotics are needed. In this study, we aimed to test the ability of mesobiliverdin IXα-enriched microalgae (MBV IXα-enriched microalgae) to eliminate reliance on antibiotics to promote intestinal health in piglets. Eighty 28-day-old weaned piglets were randomly allocated to four groups each with four replicate pens and five piglets per pen. The dietary treatments were a basal diet as control (NC), basal diet plus 0.05% tylosin (PC), basal diet plus 0.1% or 0.5% MBV IXα-enriched microalgae as low (MBV-SP1) or high (MBV-SP2) dose respectively. All treated animals showed no significant differences in live weight, average daily gain and feed efficiency compared to control animals. Histological examination showed that MBV-SP1 and particularly MBV-SP2 increased the ratio of villus height to crypt depth in the jejunum and ileum compared to NC (p < 0.05). Similarly, tylosin treatment also increased villi lengths and the ratio of villus height to crypt depth in the jejunum and ileum compared to the NC (p < 0.05). MBV-SP1 and particularly MBV-SP2 reduced the levels of inflammatory cytokines interleukin-6 and tumour necrosis factor-alpha in the small intestine. MBV-SP2 and tylosin similarly reduced the lipid peroxidation marker (TBARS value) in the duodenum and ileum. In conclusion, feed supplementation with MBV IXα-enriched microalgae improved gut health by villus height and production of immunomodulators that correlated with down-regulated secretion of inflammatory cytokines.

A statistical approach to identify prevalent virulence factors responsible for post-weaning diarrhoeic piglets.

A statistical approach was carried out to identify the prevalent virulence factors responsible for post-weaning diarrhoea (PWD). Healthy piglets' faecal samples and diarrhoeic piglets' rectal swab specimens were secured. Twenty-six (26) and 100 independent enterotoxigenic Escherichia coli (ETEC) strains were subsequently isolated. These strains were assessed utilising polymerase chain reaction to identify the encoding genes of six virulence factors: heat-labile enterotoxin (LT; encoded by eltAB), heat-stable enterotoxin A (STa; encoded by estA), heat-stable enterotoxin B (STb; encoded by estB), enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1; encoded by astA), Shiga toxin 2e (Stx2e; encoded by stx2e), and F18 fimbriae (encoded by fedA). The LT and ST secretions were investigated using enzyme-linked immunosorbent assays. From direct observation, no stx2e was evident in the 126 strains. Among the 26 strains retrieved from the healthy piglets, none harboured fedA or secreted LT; 23% (6/26) secreted ST, and 50% (13/26) carried astA. A statistical regression was applied on the 100 E. coli strains retrieved from the diarrhoeic piglets, where fedA was set as the dependent variable and the enterotoxin secretions were set as the independent variables. The results exhibit that the LT secretion was the only significant factor (P < 0.000 1) correlated to fedA in the diarrhoeic piglets; thus, it is concluded that the prevalent virulence factors for PWD were the ECET strain with F18 fimbriae adhesion and LT secretion, but not astA or stx2e.

Inhibition of pro-inflammatory mediator expression in macrophages using wood vinegar from griffith's ash.

Macrophages are essential for host defense as they control foreign pathogens and induce acquired immune responses. Activated macrophages secrete pro-inflammatory reactive substances causing local cell and tissue inflammatory response, which helps an organism resist the invasion of foreign pathogens. Excessive or chronic inflammation can cause several diseases. Previous studies have reported that vinegar treatment decreases the levels of several inflammatory cytokines and biomarkers, including mitogen-activated protein kinases, cyclooxygenase-2, inducible nitric oxide synthase (iNOS), and nitric oxide (NO). However, the benefits of wood vinegar produced from Griffith's ash (Fraxinus formosana Hayata) in reducing inflammation have not been investigated yet. Thus, assuming that wood vinegar exerts anti-inflammatory effects in macrophages, in this study, we investigated the potential anti-inflammatory effects of the wood vinegar from Griffith's ash using a lipopolysaccharide (LPS)-induced inflammatory response model in RAW264.7 macrophages. We showed that the wood vinegar inhibited the production of iNOS, NO, and interleukin 6. In addition, we found that the wood vinegar reduced the phosphorylation levels of p38 and protein kinase C-α/δ in the LPS-stimulated RAW264.7 macrophages. Based on these results, we suggest that the produced wood vinegar can reduce inflammation in LPS-activated macrophages.

Bacillus licheniformis-Fermented Products Reduce Diarrhea Incidence and Alter the Fecal Microbiota Community in Weaning Piglets.

Prophylactic use of antibiotics in-feed has been effective in decreasing the incidence of diarrhea in weaning piglets. However, the overuse of antibiotics as prophylactic or therapeutic agents in animal feed leads to the evolution of drug-resistant bacteria and antibiotic residues in pigs. This study investigated the effects of Bacillus licheniformis-fermented products on diarrhea incidence and the fecal microbial community in weaning piglets. A total of 120 crossbred piglets with an average initial body weight of 9.87 ± 1.43 kg were randomly allotted to four dietary treatments consisting of three replicate stalls with 10 piglets in each. The dietary treatments comprised a basal diet as control, control plus 1 g/kg or 4.5 g/kg of B. licheniformis-fermented products, and control plus 30 mg/kg antibiotics (bacitracin methylene disalicylate). Results showed that 4.5 g/kg of B. licheniformis-fermented product supplementation significantly reduced diarrhea incidence in weaning piglets. Principal coordinate analysis and a heatmap of species abundance indicated distinct clusters between the groups treated with antibiotics and B. licheniformis-fermented products. The bacterial richness and evenness in the feces decreased in weaning piglets fed 1 g/kg of B. licheniformis-fermented products and antibiotics. The abundance of the genera [Ruminococcus] gauvreauii group, Ruminococcaceae UCG-005, and Ruminococcaceae UCG-008 in the feces decreased in weaning piglets fed B. licheniformis-fermented products or antibiotics. The average abundance of the genus Prevotella 9 in the feces was positively correlated with the concentration of B. licheniformis-fermented products and negatively correlated with the diarrhea incidence in weaning piglets. Furthermore, the average abundance of the genus Prevotella 9 in the feces was positively correlated with the growth performance of weaning piglets. These results demonstrate that B. licheniformis-fermented products can improve diarrhea incidence and fecal microflora composition in weaning piglets.

Medium-chain triglyceride as an alternative of in-feed colistin sulfate to improve growth performance and intestinal microbial environment in newly weaned pigs.

Five hundred and twenty-eight newly weaned pigs were given four treatments, with eight replicates per treatment. Sixteen to 18 pigs were assigned per replicate and were fed diets supplemented with 0 or 3% medium-chain triglyceride (MCT) and 0 or 40 ppm colistin sulfate (CS) in a 2 × 2 factorial arrangement for 2 weeks. The results showed that dietary supplementation with MCT improved the gain-to-feed ratio during days 3-7 and in the overall period (P < 0.05). Dietary supplementation with MCT decreased coliforms counts (C) in colon and rectum content (P < 0.05). Dietary supplementation with CS decreased C and lactic acid bacteria plus C counts (L + C) in cecum (P < 0.05), and C, L + C (P < 0.01) and ratio of L and C (P < 0.05) in colon and rectum contents. The lack of interactions between MCT and CS indicates different modes of action and additive effects between the two supplementations. In conclusion, supplementation with MCT in diet with or without CS could improve the intestinal microbial environment and the feed utilization efficiency of newly weaned pigs.