Abstract

This study investigated the in vitro efficacy of extracts of Mangifera indica and Azadirachta indica bark obtained by different extraction methods. Also, in an eight-week trial, the effect of these extracts on the performance of broiler chickens were evaluated. The barks were collected, air-dried and pulverized. The samples were extracted using maceration, infusion, and decoction methods. The extracts were screened for their activity against Escherichia coli and Streptococcus aureus. Two hundred and eighty-eight birds were divided into two groups (144 each) administered with A. indica or M. indica. Each group was subdivided into four subgroups, including control subgroup (no herb) and subgroups administered with bark extracted by one of the three extraction methods. The birds on herbal treatments were not given antibiotics. Results showed that the growth of E. coli was more inhibited by the various extracts irrespective of the methods of extraction. Weights were significantly influenced by the interaction between herb types and extraction methods at the starter phase. Infused herbs induced mortality at the finisher phase. In conclusion, S. aureus was more susceptible to the extracts compared to E. coli. However, decocted A. indica and M. indica bark, as well as macerated M. indica, showed antimicrobial potency against E. coli. It can be recommended that neem or mango bark extracted by maceration or decoction can be administered orally to broiler chickens especially at the starter phase, for improved performance and reduced mortality.