Gut Microbiota, Blood Metabolites, and Spleen Immunity in Broiler Chickens Fed Berry Pomaces and Phenolic-Enriched Extractives
Citation
Das, Q., Islam, M.R., Lepp, D., Tang, J., Yin, X., Mats, L., Liu, H., Ross, K., Kennes, Y.M., Yacini, H., Warriner, K., Marcone, M.F., Diarra, M.S. (2020). Gut Microbiota, Blood Metabolites, and Spleen Immunity in Broiler Chickens Fed Berry Pomaces and Phenolic-Enriched Extractives. Frontiers in Veterinary Science, [online] 7 http://dx.doi.org/10.3389/fvets.2020.00150
Plain language summary
Antibiotics have been used to prevent diseases such as intestinal necrosis called necrotic enteritis in broilers. Due to the recent restriction of antibiotics use in food animal production and the increasing consumers’ demand for antibiotic-free and organic broiler meat, there is an urgent need to develop cost-effective strategies for antibiotic-free and organic broilers to maintain and or improve their health, productivity and safety. Berry pomaces, a by-product of the fruit processing industry, contain several compounds with heath promoting and antimicrobial properties against pathogenic bacteria regardless of their antibiotic resistance profile. Currently, the use of berry by-products as feed supplements during broiler chicken production is limited. Therefore, the present study investigated the effects of feed supplementation with different doses (1 or 2%) of organic cranberry (CP1 and CP2) and wild blueberry (BP1 and BP2) pomaces as well as their extracts at 150 (COH150 and BOH150) or 300 ppm (COH300 and BOH300) in broilers raised for 30 days. Results showed that COH300 and BOH300 in feed increased the bodyweight during the first 10 days and from 10 to 20 days-old of age, respectively; while COH150 improved the overall feed efficiency compared to control. The lowest prevalence of necrotic enteritis was observed with CP1 and BP1 compared to the traditional antibiotic bacitracin in feed. Although, no clear evidence of a dose-dependent response was noted, feed supplementation with berry products improved intestinal health by modulating the abundance of gut microbes such as Acidobacteria and Lactobacillaceae, while simultaneously influencing immunity in broilers.
Abstract
This study evaluated the performance, gut microbiota, and blood metabolites in broiler chickens fed cranberry and blueberry products for 30 days. A total of 2,800 male day-old broiler Cobb-500 chicks were randomly distributed between 10 diets: control basal diet; basal diet with bacitracin (BACI); four basal diets with 1 and 2% of cranberry (CP1, CP2) and blueberry (BP1, BP2) pomaces; and four basal diets supplemented with ethanolic extracts of cranberry (COH150, COH300) or blueberry (BOH150, BOH300) pomaces. All groups were composed of seven replicates (40 birds per replicate). Cecal and cloacal samples were collected for bacterial counts and 16S rRNA gene sequencing. Blood samples and spleens were analyzed for blood metabolites and gene expressions, respectively. The supplementation of COH300 and BOH300 significantly increased the body weight (BW) during the starting and growing phases, respectively, while COH150 improved (P < 0.05) the overall cumulated feed efficiency (FE) compared to control. The lowest prevalence (P = 0.01) of necrotic enteritis was observed with CP1 and BP1 compared to BACI and control. Cranberry pomace significantly increased the quinic acid level in blood plasma compared to other treatments. At days 21 and 28 of age, the lowest (P < 0.05) levels of triglyceride and alanine aminotransferase were observed in cranberry pomace and blueberry product–fed birds, respectively suggesting that berry feeding influenced the lipid metabolism and serum enzyme levels. The highest relative abundance of Lactobacillaceae was found in ceca of birds fed CP2 (P < 0.05). In the cloaca, BOH300 significantly (P < 0.005) increased the abundances of Acidobacteria and Lactobacillaceae. Actinobacteria showed a significant (P < 0.05) negative correlation with feed intake (FI) and FE in COH300-treated birds, whereas Proteobacteria positively correlated with the BW but negatively correlated with FI and FE, during the growing phase. In the spleen, cranberry products did not induce the release of any pro-inflammatory cytokines but upregulated the expression of several genes (IL4, IL5, CSF2, and HMBS) involved in adaptive immune responses in broilers. This study demonstrated that feed supplementation with berry products could promote the intestinal health by modulating the dynamics of the gut microbiota while influencing the metabolism in broilers.