Simple SummaryHeat stress is a serious issue in commercial broiler production in hot and humid countries, including Malaysia. Exposure of broilers to heat stress affects their health and productivity. In this context, antibiotics are widely used at sub-therapeutic levels as growth promoters to reduce stress and infectious diseases in order to sustain productivity in commercial broiler farms. However, the extensive use of antibiotics as growth promoters for a long time leads to the development of antibiotic-resistant bacteria and the possibility of antibiotic-resistant genes being transferred among organisms. Recently, postbiotics produced by Lactobacillus plantarum have been widely studied as a feed additive in order to replace in-feed antibiotics. However, to date, no studies have investigated the role of postbiotics in feed for broilers under heat stress.AbstractThe effects of feeding different postbiotics on growth performance, carcass yield, intestinal morphology, gut microbiota, immune status, and growth hormone receptor (GHR) and insulin-like growth factor 1 (IGF-1) gene expression in broilers under heat stress were assessed in this study. A total of 252 one-day-old male broiler chicks (Cobb 500) were randomly assigned in cages in identical environmentally controlled chambers. During the starter period from 1 to 21 days, all the birds were fed the same basal diet. On day 22, the birds were weighed and randomly divided into six treatment groups and exposed to cyclic high temperature at 36 ± 1 °C for 3 h per day from 11:00 to 14:00 until the end of the experiment. From day 22 to 42 (finisher period), an equal number of birds were subjected to one of the following diets: NC (negative control) basal diet; PC (positive control) basal diet + 0.02% oxytetracycline; or AA (ascorbic acid) basal diet + 0.02% ascorbic acid. The other three groups (RI11, RS5 and UL4) were basal diet + 0.3% different postbiotics (produced from different Lactobacillus plantarum strains, and defined as RI11, RS5 and UL4, respectively). The results demonstrated that birds fed RI11 diets had significantly higher final body weight, total weight gain and average daily gain than the birds that received the NC, PC and AA treatments. The feed conversion ratio was significantly higher in the RI11 group compared with the other groups. Carcass parameters were not affected by the postbiotic-supplemented diet. Postbiotic supplementation improved villi height significantly in the duodenum, jejunum and ileum compared to the NC, PC and AA treatments. The crypt depth of the duodenum and ileum was significantly higher in NC group compared to other treatment groups except RI11 in duodenum, and UL4 in ileum was not different with NC groups. The villus height to crypt depth ratio of duodenum and ileum was significantly higher for the postbiotic treatment groups and AA than the PC and NC treatment groups. The postbiotic RI11 group recorded significantly higher caecum total bacteria and Lactobacillus count and lower Salmonella count compared to the NC and PC tr...

Postbiotics from Lactobacillus plantarum have been reported to improve growth performance, nutrient utilization, immune status and gut health in livestock. However, there is scarce information on the antioxidant activity of postbiotics and its modulation of antioxidant activity and rumen barrier function in animals. We investigated the antioxidant activity of postbiotics from L. plantarum RG14, RG11 and TL1 and dietary effects in post-weaning lambs on serum and ruminal antioxidant activity, hepatic antioxidant enzymes and ruminal barrier function. Postbiotic RG14 showed the highest antioxidant activity in both 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay and was chosen to be evaluated in animal trials. Twelve post-weaning Dorper lambs were allotted to the control group and postbiotic group (0.9% (v/w) postbiotic RG14). The improvement in antioxidant activity of the postbiotic group was observed by greater glutathione peroxidase (GPX) in serum and ruminal fluid and lower serum TBARS. The findings were strengthened by the upregulation of hepatic GPX1, GPX4 and copper, zinc superoxide dismutase (Cu/Zn SOD) in the postbiotic group. Lambs received postbiotics had higher regulation of rumen barrier function through upregulation of tight junction protein (TJP), occludin (OCLD), claudin-1 (CLDN1) and CLDN4. The current study demonstrated that dietary postbiotics enhanced the serum and ruminal fluid antioxidant activity, reduced the serum lipid peroxidation and upregulated hepatic antioxidant enzymes and ruminal barrier function.

We investigate the effects of postbiotic Lactobacillus plantarum RG14 on gastrointestinal histology, haematology, mucosal IgA concentration, microbial population and mRNA expression related to intestinal mucosal immunity and barrier function. Twelve newly weaned lambs were randomly allocated to two treatment groups; the control group without postbiotic supplementation and postbiotic group with supplementation of 0.9% postbiotic in the diet over a 60-day trial. The improvement of rumen papillae height and width were observed in lambs fed with postbiotics. In contrast, no difference was shown in villi height of duodenum, jejunum and ileum between the two groups. Lambs received postbiotics had a lower concentration of IgA in jejunum but no difference in IgA concentration in serum and mucosal of the rumen, duodenum and ileum. In respect of haematology, postbiotics lowered leukocyte, lymphocyte, basophil, neutrophil and platelets, no significant differences in eosinophil. The increase in of IL-6 mRNA and decrease of IL-1β, IL-10, TNF mRNA were observed in the jejunum of lambs receiving postbiotics. Postbiotics also improved the integrity of the intestinal barrier by the upregulation of TJP-1, CLDN-1 and CLDN-4 mRNA. Postbiotic supplementation derived from L. plantarum RG14 in post-weaning lambs enhance the ruminal papillae growth, immune status and gastrointestinal health.

Background Postbiotics have been established as potential feed additive to be used in monogastric such as poultry and swine to enhance health and growth performance. However, information on the postbiotics as feed additive in ruminants is very limited. The aim of this study was to elucidate the effects of supplementation of postbiotics in newly-weaned lambs on growth performance, digestibility, rumen fermentation characteristics and microbial population, blood metabolite and expression of genes related to growth and volatile fatty acid transport across the rumen epithelium. Results Postbiotic supplementation increased weight gain, feed intake, nutrient intake and nutrient digestibility of the lambs. No effect on ruminal pH and total VFA, whereas butyrate and ruminal ammonia-N concentration were improved. The lambs fed with postbiotics had higher blood total protein, urea nitrogen and glucose. However, no difference was observed in blood triglycerides and cholesterol levels. Postbiotics increased the population of fibre degrading bacteria but decreased total protozoa and methanogens in rumen. Postbiotics increased the mRNA expression of hepatic IGF-1 and ruminal MCT-1. Conclusions The inclusion of postbiotics from L. plantarum RG14 in newly-weaned lambs improved growth performance, nutrient intake and nutrient digestibility reflected from better rumen fermentation and microbial parameters, blood metabolites and upregulation of growth and nutrient intake genes in the post-weaning lambs.

The purpose of this work was to evaluate the impacts of feeding different postbiotics on oxidative stress markers, physiological stress indicators, lipid profile and meat quality in heat-stressed broilers. A total of 252 male Cobb 500 (22-day-old) were fed with 1 of 6 diets: A basal diet without any supplementation as negative control (NC); basal diet + 0.02% oxytetracycline served as positive control (PC); basal diet + 0.02% ascorbic acid (AA); or the basal diet diet + 0.3% of RI11, RS5 or UL4 postbiotics. Postbiotics supplementation, especially RI11 increased plasma activity of total-antioxidant capacity (T-AOC), catalase (CAT) and glutathione (GSH), and decreased alpha-1-acid-glycoprotein (α1-AGP) and ceruloplasmin (CPN) compared to NC and PC groups. Meat malondialdehyde (MDA) was lower in the postbiotic groups than the NC, PC and AA groups. Plasma corticosterone, heat shock protein70 (HSP70) and high density lipoprotein (HDL) were not affected by dietary treatments. Postbiotics decreased plasma cholesterol concentration compared to other groups, and plasma triglyceride and very low density lipoprotein (VLDL) compared to the NC group. Postbiotics increased breast meat pH, and decreased shear force and lightness (L*) compared to NC and PC groups. The drip loss, cooking loss and yellowness (b*) were lower in postbiotics groups compared to other groups. In conclusion, postbiotics particularly RI11 could be used as an alternative to antibiotics and natural sources of antioxidants for heat-stressed broilers.