effect of genetic strains (ross 308, cobb 500 and hubbard f15) on immune response against newcastle disease vaccine in broiler chickens

Background: immune responses are crucial for optimal health and can be affected by several factors including host genetics. genetic selection would seem to have some effects on immunological memory. some genes control disease resistance in broiler chickens. noticeable increase in the production potential of broiler chickens has been observed recently. one way to increase the production potential of commercial broiler chickens is utilization of genetic selection. genetic enhancements in growth rate and carcass weight reported in new broiler lines, and these new lines have shorter breeding period. high growth rate in broiler chickens has some negative consequences. fast- growing birds as compared to slower-growing birds, have high mortality, because high growth rate may lead to metabolic diseases or infections. objectives: the current study examines immune response against newcastle disease vaccine in ross 308, cobb 500, and hubbard f15 strains. materials and methods: a total of 36 000 one-day-old broiler chicks of hubbard f15, cobb 500, and ross 308 strains were divided into 3 equal groups with 2 replicates and 6000 birds per replicate. the birds were reared under similar conditions from 1-day-old to 49 days of age. all groups were vaccinated against newcastle disease. blood samples were collected before vaccination and on 7, 17, 27, 35, 42, 48 days of age and antibody titer against newcastle disease vaccine was determined by hemagglutination inhibition (hi) test. results: the cobb 500 and hubbard f15 stains, respectively, had the highest and the lowest immune responses against newcastle disease vaccine. ross 308 had the second status among the strains. conclusion: on the basis of present study, cobb 500 and ross 308 chickens had better immune responses against newcastle disease vaccine and therefore are recommended for rearing, respectively.