Effect of Butyric Acid on Performance, Gastrointestinal Tract Health and Carcass Characteristics in Broiler Chickens

An experiment was conducted to study the effect of graded levels of butyric acid (butyrate) on performance, gastrointestinal tract health and carcass characteristics in young broiler chickens.Control starter (0-3 wk) and finisher (4-5 wk) diets were formulated to contain 2,900 kcal ME/kg and 22% CP, and 3,000 kcal ME/kg and 20% CP, respectively.Subsequently, four other experimental diets were formulated to contain 0.05% antibiotic (furazolidone) or 0.2, 0.4 and 0.6% butyric acid.Each diet was fed at random to 8 replicates of 6 chicks each throughout the experimental period (0-5 wk).The results showed that 0.4% butyrate in the diet was similar to antibiotic in maintaining body weight gain and reducing E. coli numbers but superior for feed conversion ratio.No added advantage on these parameters was obtained by enhancing the concentration of butyrate from 0.4 to 0.6% in the diet.Feed intake and mortality were not influenced by the dietary treatments.A reduction in pH of the upper GI tract (crop, proventiculus and gizzard) was observed by inclusion of butyrate in the diets of broilers compared to either control or antibiotic-fed group.Butyrate at 0.4% was more effective in reducing the pH than 0.2% butyrate.Within the lower GI tract, 0.4 and 0.6% butyrate was effective in lowering pH in the duodenum, but no effect was found in either the jejunum or ileum.The villus length and crypt depth in the duodenum increased significantly in all the butyrate treated diets irrespective of the level tested.Carcass yield was higher and abdominal fat content was lower significantly in all the butyrate treatment groups compared to the control or antibiotic group.From these findings, it is concluded that 0.4% butyric acid supplementation maintained performance, intestinal tract health, and villi development and carcass quality in broiler chickens.