Effect of a probiotic mixture on intestinal microflora, morphology, and barrier integrity of broilers subjected to heat stress

Abstract

The current study investigated the efficacy of a probiotic mixture on ameliorating heat stress-induced impairment of intestinal microflora, morphology, and barrier integrity in broilers. The probiotic mixture contained Bacillus licheniformis, Bacillus subtilis, and Lactobacillus plantarum. Three hundred sixty 21-d-old Ross 308 male broilers were allocated in 4 experimental treatments, each of which was replicated 6 times with 15 broilers per replicate. A 2 × 2 factorial design was used in the study, and the main factors were composed of diet (basal diet or addition of 1.5 g/kg of probiotic mixture) and temperature (thermoneutral zone or heat stress). From d 22 to 42, birds were either raised in a thermoneutral zone (22°C) or subjected to cyclic heat stress by exposing them to 33°C for 10 h (from 0800 to 1800) and 22°C from 1800 to 0800. Compared with birds kept in the thermoneutral zone, birds subjected to heat stress had reduced ADG and ADFI; lower viable counts of Lactobacillus and Bifidobacterium and increased viable counts of coliforms and Clostridium in small intestinal contents; shorter jejunal villus height, deeper crypt depth, and lower ratio of villus height to crypt depth; decreased jejunal transepithelial electrical resistance and a higher level of jejunal paracellular permeability of fluorescein isothiocyanate dextran 4 kDa; and downregulated protein levels of occludin and zonula occludens-1 (P < 0.05). Supplemental probiotics increased (P < 0.05) small intestinal Lactobacillus and Bifidobacterium, jejunal villus height, protein level of occludin, and decreased (P < 0.05) feed to gain ratio and small intestinal coliforms. These results indicate that dietary addition of probiotic mixture was effective in partially ameliorating intestinal barrier function. But no temperature × diet interaction was observed in the present study, revealing that the supplemented probiotics had the same effect at both temperatures.

Effect of dietary supplementation with &lt;i&gt;Rhizopus oryzae&lt;/i&gt; or &lt;i&gt;Chrysonilia crassa&lt;/i&gt; on growth performance, blood profile, intestinal microbial population, and carcass traits in broilers exposed to heat stress

“…This finding was in accordance with Sohail et al (2013Sohail et al ( , 2015, who reported that neither chronic HS nor probiotic treatments affected the intestinal microbial communities of broilers. Nevertheless, our finding was in contrast to Song et al (2014), who showed an improvement of microbial communities of the intestine in HS broilers fed probiotics. With regard to the HS effect, it was most likely that the acclimatization of birds to chronic HS may ameliorate the adverse effect of HS on the intestinal microbial population in HS birds.…”

“…Sohail et al (2010) reported that probiotics improved the physiological condition of HS birds. Likewise, probiotics prevented an intestinal microbial shift (Song et al, 2014;Jahromi et al, 2015) and improved humoral immunity in birds during HS (Sohail et al, 2010). With regard to antioxidants, supplementations of vitamin C, E and chromium in feed improved blood profile, immune responses, antioxidant status and performance (Khan et al, 2011Tawfeek et al, 2014) and reversed the increased fat yield in HS broilers (Tawfeek et al, 2014).…”

Short-term exposure to heat stress attenuates appetite and intestinal integrity in growing pigs1

“…In rodents (Lambert et al, 2002) and poultry (Song et al, 2013(Song et al, , 2014, HS significantly affects small intestinal permeability as assessed by either TER or FD4 permeability. Even within a short time period (60 minutes), heat-stressed rodents at 41.5 to 42°C core temperature had increased FD4 permeability.…”

Breast Meat Quality and Protein Functionality of Broilers with Different Probiotic Levels and Cyclic Heat Challenge Exposure

“…For these reasons, application of commercial probiotic products has been increasingly adopted in the poultry industry (Park and Kim, 2014). Recent studies have reported that probiotic supplementation could be an effective feeding strategy to reduce detrimental impacts of heat stress on growth performance and health of broiler chickens (Song et al, 2014;Jahromi et al, 2016). In addition, some previous studies found the beneficial impacts of probiotic feeding on broiler meat quality, such as WHC, oxidation stability, and tenderness (Aksu et al, 2005;Ali, 2010;Bai et al, 2016Bai et al, , 2017Kim et al, 2017;Zhou et al, 2010).…”