Effect of coated sodium butyrate in diet on performance, gut microbiota, ileal digestibility, serum nutrient fractions, immune responses and bone mineral variables in broiler chicken fed antibiotic-free diet

Abstract

Content Antibiotic growth promoters (AGP) are not recommended in broiler diets due to the possible threat of microbial resistance and residues in meat. Aim Two experiments were conducted to study the possibility of utilising coated sodium butyrate (CSB) as an alternative to AGP (500 g/t) in broiler (1–42 days) chicken diet. Method In Experiment 1, a positive control (PC with AGP), a negative control (NC, without AGP) and CSB diet (150 g/t), and in Experiment 2, four diets, i.e. PC, NC, and CSB at two concentrations (75 and 150 g/t) were prepared. Each diet was offered ad libitum to 10 floor pens (25 broilers) with built up litter as bedding material. Key results Bodyweight gain (BWG) and feed intake (FI) were not affected, while feed efficiency (FE) at both Day 21 and Day 42 reduced in broilers fed the NC compared with those in the AGP-fed group (Experiment 1). Inclusion of CSB (150 g/t) improved the FE similar to the AGP group. In Experiment 2, BWG and FI were not affected, while FE improved in CSB groups compared with the AGP or NC. The colony count of E. coli and C. perfringes increased in the NC group compared with the AGP group and the count in CSB groups was similar to that in the AGP group. The ileal digestibility of nitrogen (CSB150 g) and energy (CSB75 and CSB150 g) and tibia variables (total ash and breaking strength) reduced in the NC group compared with the AGP groups and supplementation of CSB improved all these parameters similar to the AGP group. Conclusions On the basis of the data, it is concluded that CSB (75 or 150 g/t) can be used as an alternative to the AGP (bacitracin methylene disalysilate) in broiler chicken diet. The improvement in broiler performance with CSB in diet could be attributed to the increased ileal digestibility of nitrogen and energy, bone mineralisation and reduction in pathogenic bacterial count (E. coli and C. perfringes) in the gut. Implications Use of AGP in broiler diets can be avoided with inclusion of coated butyric acid, without affecting the broiler performance.