Comparative study of the effect of alternative and antibiotic feed additives on the performance and intestinal histomorphometrical parameters of broiler chickens

A four replicate study was conducted to compare the effects of alternative feed additives (prebiotic, ECOCELL® and butyric acid, Baby c4®) to an antibiotic growth promoter (bacitracin) on the performance and histomorphometrical parameters of the small intestine of 192, 1-day-old Ross broiler chicks. The used chicks were randomly assigned to one out of four dietary treatments for 6 weeks (each treatment contained four replicates, 12 birds each). Replicate dietary treatments were as follow: 1- control (basal diet), 2-basal diet + prebiotic, 3-basal diet + butyric acid and 4-basal diet + antibiotic growth promoter. The results showed that body weight, weight gain and feed intake were not affected by dietary treatments. Prebiotic had significantly improved (p<0.05) feed conversion ratio (FCR) in 22-42 days and total period compared with the control nontreated and butyric acid fed broilers. The addition of either prebiotic or antibiotic significantly increased the villus height in duodenum (P<0.001), while prebiotic increased duodenum and ileum villus width compared with other treatments. The duodenal crypt depth was significantly increased by antibiotic or organic acid compared with prebiotic and control (P<0.01). In conclusion, prebiotic displayed a greater efficacy as growth promoter for broilers, but butyric acid glycerides do not promote broiler’s growth.   Key words: Prebiotic, organic acid, antibiotic, performance, histomorphometry, small Intestine, broiler chicken.