Effect of protein rich diet on experimental pathology of necrotic enteritis in broilers

Abstract

This study was designed to know the effect of protein rich diet (50% fish meal) on the experimental pathology of necrotic enteritis in broilers. The Clostridium (Cl.) perfringens was obtained from the Department of Pathology, Bangladesh Agricultural University. Reconfirmation and recharacterization of Cl. perfringens were performed by culture, microscopic examination, staining and biochemical tests. The experimental pathologic studies were performed with supplementation of protein rich diet and challenged with Cl. perfringens in broilers. The dose of the inoculum for experimental infection with Cl. perfringens was 1x108 CFU/2.5ml. Fifteen birds of 21 days old were divided into 3 (A, B and C) groups each containing 5 birds. Birds of group A were fed with 50% fish meal at a rate of 500gm /kg of feed from day 21 to day 34 and challenged from day 28 to day 32 with 1x108 CFU/2.5ml. Birds of group B were fed with normal feed and challenged on day 28 for consecutive five days. Group C was kept as control with commercial normal pellet without Cl. perfringens. Birds of all groups were observed up to 34 days of age for clinical signs. Eighty percent (4/5) of the birds of group A developed moderate clinical signs like diarrhoea, ruffled feather and less feed intake whereas 40% (2/5) birds of group B developed same clinical signs like group A but in mild form. There was no mortality in any groups. All the birds were sacrificed at Day 35. Severe necrosis and hemorrhage in intestine, enlarged liver and hemorrhage in the base of heart were noted in the birds of group A. On an average 2-5 bacteria were found in impression smear of intestines in higher magnification (100x), and anaerobic bacteria counted from intestinal content was 1.51x107CFU/ml. In histopathology, necrosis and reactive cells were found in liver, heart, lung and sloughing off intestinal epithelium was also found in intestines. On the other hand similar lesions like group A were observed in the birds of group B but in moderate form and no bacteria was found in impression smears of intestines. Anaerobic bacteria counted from intestinal content of this group was 1.1x107CFU/ml. In histopathology necrosis, reactive cells were found but less than group A. The birds of group C were normal in all parameters. However, anaerobic bacteria count from the intestinal content was 0.8x107CFU/ml. From this study, it may be concluded that protein rich diet is a predisposing factor for necrotic enteritis in broilers. DOI: http://dx.doi.org/10.3329/bjvm.v11i1.17729 Bangl. J. Vet. Med. (2013). 11 (1): 21-29