Effects of substitution of soybean meal with rapeseed meal and glutamine supplementation on growth performance, intestinal morphology, and intestinal mucosa barrier of Qiandongnan Xiaoxiang Chicken

Abstract

Objective The present study was to evaluate the effects of different rapeseed meal substitution (RSM) and glutamine (Gln) supplementation on growth performance, intestine morphology, and intestinal mucosa barrier of broilers. Methods Four hundred and twenty Qiandongnan Xiaoxiang Chicken at 1 day of age with similar weight were chosen and were randomly assigned into 7 groups, consisting of 10 replicates per group and 6 broilers per replicate. Three groups were provided with diets separately containing 0%, 10%, and 20% RSM, and the other four groups were fed with diets separately supplemented with 0.5% and 1% Gln based on the inclusion of 10% and 20% RSM. At 21 and 42 days of age, 10 broilers per group were chosen to collect plasma and intestinal samples for further analysis. Results The results showed that 10% RSM decreased average daily feed intake (ADFI) and average daily weight gain (ADG) of broilers at 21 days of age (p<0.05). Furthermore, both ADFI and ADG of broilers at 21 and 42 days of age were decreased by 20% RSM, while feed conversion ratio (FCR) was increased (p<0.05). Besides, 10% RSM resulted in lower intestinal villus height and the ratio of villus height to crypt depth, deeper crypt depth (p< 0.05), combined with the lower mRNA expressions of occludin, claudin-1, and zonula occludens-1 (ZO-1) in broilers at 21 days of age (p<0.05). Similar results were also observed in broilers at 21 and 42 days of age fed with 20% RSM. However, 1% Gln improved the growth performance of broilers fed with 10% and 20% RSM (p<0.05), ameliorated intestine morphology and elevated mRNA expressions of occludin, claudin-1 and ZO-1 (p<0.05). Conclusion In conclusion, the increasing inclusion of RSM resulted in more serious effects on broilers, however, 1.0% Gln could reverse the negative effects induced by the inclusion of RSM.

Keywords

• glutamine
• intestinal morphology
• qiandongnan xiaoxiang chicken
• rapeseed meal
• tight junction protein