Effects of Antibiotic Growth Promoter Replacement with Organic Acids, on Small Intestinal Morphology, Performance and Carcass Characteristics of Broiler Chickens

The present study was conducted to evaluate the effects of growth promoters Avilamycin, Butyric acid and Nutracid Focus® on performance, carcass characteristics and intestinal morphology of broiler chickens. A total of 176 one-day old male broiler chicks (Ross 308) were randomly allocated to four treatments with 4 replicates and 11 birds each according a completely randomized design and fed a basal diet or diets supplemented with 0.01% Avilamycin, 0.25% Butyric acid and 0.1% Nutracid Focus throughout the experimental period respectively. At days 21 and 42 of age, three and four birds per treatment were selected respectively and killed for analysis of carcass characteristics and intestinal morphology. In analysis of variance, no significant differences were observed between the treatments for feed consumption, body weight gain and feed conversion ratio, and also relative weights of carcass, liver, heart and gizzard (P>0.05). Furthermore in orthogonal array test, the supplementation of organic acids in comparison with control group decreased the abdominal fat weight and increased the goblet cell numbers in jejunum (P<0.05). In addition, the villus length and villus length to crypt depth ratio in duodenum were higher than those for Avilamycin fed birds (P<0.05). It was concluded that dietary supplementation of organic acids instead of growth promoter antibiotics could have some advantages on abdominal fat weight and intestinal morphological parameters in broiler chickens.