GROWTH RESPONSE AND ANTIVIRAL POTENTIALS OF NEEM (AZADIRACHTA INDICA J.) AND SCENT (OCIMUM SANCTUM L.) LEAF MEALS AGAINST NEWCASTLE AND INFECTIOUS BURSAL DISEASES IN BROILER CHICKS

Résumé

Newcastle disease (ND) and infectious bursal disease (IBD) are the most feared viral disease of poultry. Viral reversion, vaccine failure, risk of autoimmune diseases and allergic disorder has led to the search for alternatives for vaccination. The effects of neem (Azadirachta indica) and scent (Ocimum santum) leaf meals fed singly or in combination on the growth performance and their antiviral potencies in broiler chicks were investigated. Two hundred 1-day old Ross 308 unsexed broiler chicks were randomly allotted to 5 treatments, consisting of 5 replicates with 8 birds each. Treatments 1 and 2 were basal diets with no leaf meals, treatments 3, 4 and 5 had the basal diets plus 3% neem leaf meal (NLM), 3% scent leaf meal (SLM) and the blend of 2% NLM + 2% SLM, respectively. Birds in treatments 2-5 were unvaccinated against Newcastle disease and Infectious bursal disease while birds in treatment 1 were vaccinated. Performance indices were measured on a weekly basis. At day-21, blood samples were randomly collected from 2 birds per replicate for haemagglutination inhibition and agar gel precipitation tests. Data were subjected to descriptive statistics and ANOVA at P<0.05. Birds fed diets supplemented with a combination of 2% neem + 2% scent leaves had the highest weight gain (819.49g/b) and lowest feed conversion ratio (1.83). In conclusion, birds fed diets supplemented with 3% neem and 3% scent leaf meals singly had haemagglutination inhibition titre values and conferred immunity above protective threshold against Newcastle disease and produced antibodies against Infectious bursal disease.