The Effect of an Herbaceous Feed Additive and Zn-Bacitracin on Performance and Gut Morphology in Broilers Experimentally Infected with Clostridium perfringens Type A cpe-cpb2

摘要

Type A strains of C.perfringens are commonly found as part of the normal intestinal microflora of broilers and produce lethal and necrotising α toxins that are incriminated in necrotic enteritis in poultry.These strains carry a chromosomal enterotoxin gene (cpe)and in gastro intestinal diseases a gene associated with production of beta2 toxin (cpb2).Laboratory trials were conducted with Cobb broilers kept on standard corn-soy diets.Four hundred-and-sixty,day old broilers,were assorted randomly into 4 groups of 115 with 5 replicates of 23 birds per group.The birds were kept in optimal environment in pens of 1.5 × 1.5 m embedded with wood shavings.Feed and water was available ad lib.from dispensers.Of the 4 groups' one negative and one positive control group was formed.No feed additive was added either of these groups.The feed of the 1st and 2nd experimental group was supplemented at I kg/ton concentration with an herbal preparation (Herbanoplex)and Zn-bacitracin,respectively.On day 18,21 and 24 the birds of the positive control group and of the two experimental groups were inoculated orally with 2 ml of 108 CUF/ml inoculum containing Clostridium spp.Clinical signs were observed and data of production was collected and processed.Gross pathological findings of the small intestines were scored.Morphopathological measurements on villi and crypt of the small intestine were also included.Mild to severe signs of necrotic enteritis developed in each treatment groups following the experiruental infection.Of the bacteriologically challenged group,the one that received Herbanoplex additive in the daily ration proved in every respect superior to the other challenged groups.