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...

Epithiospecifier protein (ESP), a ferrous ion dependent protein, has a potential role in regulating the release of elemental sulphur, nitriles, isothiocyanates and cyanoepithioalkanes from glucosinolates. Two classes of ESP polypeptides were purified with molecular masses of 39 and 35 kDa, and we show that the previously reported instability was conditionally dependent. The 39 kDa polypeptide was made up of two distinct isozymes (5.00, 5.14) whilst several were present for the 35 kDa form of ESP (5.40^5.66). An anti-ESP antibody reacted with both the 39 and 35 kDa ESP forms in Brassica napus and strongly with a polypeptide corresponding to the 35 kDa ESP form in Crambe abyssinica, but did not detect any ESP in Sinapis alba or Raphanus sativus. A cytochrome P-450 mediated iron dependent epoxidation type mechanism is suggested for ESP.z 2000 Federation of European Biochemical Societies.

1. Four combinations of metabolites produced from strains of Lactobacillus plantarum were used to study the performance of broiler chickens. 2. A total of 432 male Ross broilers were raised from one-day-old to 42 d of age in deep litter pens (12 birds/pen). These birds were divided into 6 groups and fed on different diets: (i) standard maize-soybean-based diet (negative control); (ii) standard maize-soybean-based diet + Neomycin and Oxytetracycline (positive control); (iii) standard maize-soybean-based diet + 0.3% metabolite combination of Lactobacillus plantarum RS5, RI11, RG14 and RG11 strains (com3456); (iv) standard maize-soybean-based diet + 0.3% metabolite combination of L. plantarum TL1, RI11 and RG11 (Com246); (v) standard maize-soybean-based diet + 0.3% metabolite combination of L. plantarum TL1, RG14 and RG11 (Com256) and (vi) standard maize-soybean-based diet + 0.3% metabolite combination of L. plantarum TL1, RS5, RG14 and RG11 (Com2356). 3. Higher final body weight, weight gain, average daily gain and lower feed conversion ratio were found in all 4 treated groups. 4. The addition of a metabolite combination supplementation also increased faecal lactic acid bacteria population, small intestine villus height and faecal volatile fatty acids and faecal Enterobacteriaceae population.

BackgroundPostbiotics (metabolic products by lactic acid bacteria) and prebiotics have been established as substitute to antibiotics in order to enhance immunity and growth performance in broiler chickens. Nonetheless, insufficient information is available on the effects of postbiotics and prebiotics combination on growth performance, faecal microbiota, pH and volatile fatty acids (VFA), as well as liver insulin like growth factor 1 (IGF1) and growth hormone receptor (GHR) mRNA expressions in broiler chickens. The aim of this experiment was to evaluate the effects of different types of postbiotics with different levels of prebiotic (inulin) on broiler for those parameters.ResultsThe results showed that birds fed T3: (0.3 % RI11 + 0.8 % Inulin), T4: (0.3 % RI11 + 1.0 % Inulin), and T6: (0.3 % RG14+ 1.0 % Inulin) had higher (p < 0.05) final body weight (BW) and total weight gain (WG) than other treatments. Birds fed T3 had lower feed conversion ratio (FCR) which was significantly different from those fed with negative control diet but was similar to other treatments. Postbiotic and inulin increased (p < 0.05) faecal lactic acid bacteria (LAB) and reduced (p < 0.05) Enterobacteriaceae count. Birds fed T4 and T6 had higher faecal acetic acid and propionic acid respectively, and both had higher total VFA and lactic acid bacteria but lower pH and Enterobacteriaceae (ENT) counts compared to other treatments. The liver of birds fed T4 and T6 had higher IGF1 expression compared to other treatments while T6 had higher GHR mRNA expression compared to other treatments.ConclusionsResults indicate that the addition of postbiotics and inulin combinations had beneficial effects on total BW, feed efficiency, mucosa architecture and IGF1 and GHR mRNA expression in broiler chickens.