Butyric acid as a promising alternative to antibiotic growth promoters in broiler chicken production

The current work studied the effects of butyric acid (BA) supplementation on the growth performance, carcase characteristics, immunity, gut histology and serum biochemistry of broiler chicken. Four experimental diets were formulated: control, 20 mg bacitracin methylene di-salicylate/kg diet (BMD-supplemented), 3 g BA/kg diet and 4 g BA/kg diet. The results revealed higher body weight gain (BWG) in BA and BMD-supplemented groups. Only BMD supplementation increased the feed intake (FI) of birds, whereas BA supplementation improved feed efficiency. Expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT1) and peptide transporter (PepT1) were up-regulated due to BMD and BA supplementation. However, at 21 days post-hatching SGLT1 expression in the BMD-supplemented group was down-regulated with respect to the BA-supplemented groups. The 4 g BA/kg diet yielded better humoral and cell-mediated immune responses than the other groups. No dietary effects were observed on carcase characteristics and histomorphometry of jejunum at 7 days post-hatching. However, at 42 days old, the 4 g BA/kg diet increased villus length and width significantly. There was a significant increase in serum protein, albumin, creatinine, aspartate aminotransaminase (AST), phosphorus and calcium due to BA supplementation. However, the reverse trend was observed in serum uric acid and cholesterol, where BA supplementation decreased both and BMD supplementation decreased uric acid levels only. Based on the results it was concluded that 4 g BA/kg diet supplementation in feed is optimal for desirable broiler production.

Key words: Broiler performance; butyric acid; gut histomorphometry; immunity; nutrient transporters; serum.

Abstract published in The Journal of Agricultural Science. 2019;157(1):55-62. doi:10.1017/S0021859619000212.