Effect of organic zinc on production performances, meat performances, apparent nutrients digestibility and gut microbiota of broilers in low protein diets

Abstract

The high cost of feed and nitrogen pollution caused by high protein diets, which have become major challenges restricting sustainable development in China’s animal husbandry. Properly reducing the protein level and improving protein utilization in feed are a promising approach in solving this problem. To determine the optimal dose of methionine hydroxyl analog chelated zinc (MHA-Zn) in reduced 1.5% protein diets of broilers, total 216 1-day-old broilers were randomly allotted into 4 treatments and assess the index of growth and development at 42-days. Results showed no significant difference was observed for edible part between low protein (LP) diet group (90 mg/kg MHA-Zn) and normal diet group (P > 0.05), and adding 90 mg/kg MHA-Zn in LP diet significantly improved ileum morphology and apparent total tract digestibility (ATTD) of nutrients (P < 0.01; P < 0.05). A 16S rRNA sequencing analysis indicated that supplementing LP diet with 90 mg/kg MHA-Zn was adequate for production performance of broilers, it can promote beneficial bacteria of cecum (Lactobacillus, Butyricoccus, Oscillospira et al.) (P < 0.01). These findings will be useful for guiding organic Zn concentration optimization in LP of broilers to improve production performance through restoring the imbalance of intestinal microbiome under the premise of reducing environmental pollution.