ANTIBODY TITERS AGAINST NEWCASTLE DISEASE AND INFECTIOUS BRONCHITIS VIRUSES IN BROILER BREEDERS RAISED UNDERFLOOR VERSUS CAGE SYSTEM

Abstract

The experiment was evaluated to find out the serum antibody titer of broiler breeders raised under different rearing systems (cage vs. floor) against Newcastle disease virus and infectious bronchitis disease virus. Two hundred and forty-day-old broiler breeders were equally divided into six groups Floor (V+CH), (V+Not CH) and (Not V+CH) and cage (V+CH), (V+Not CH), and (Not V+CH). Birds were vaccinated with Mukteswar, La Sota, and Massachusetts M41 in 1st week, 3rd week, and 4th week. Blood /serum samples were collected at 42 days of age. Collected data were analyzed by using a complete randomized design. The geometric mean titer (GMT) for Newcastle disease virus (NDV) of broiler breeders reared under floor versus cage housing system was measured by using the hem agglutination inhibition test and the defensive potentiality of vaccines was measured by determining the survivability rate of chickens by challenge infection. Birds vaccinated and virus-challenged showed a protective antibody titer against Newcastle disease virus in both housing systems. Significantly higher GMT was recorded for the non-vaccinated group having virus-challenged in cage female (9.76 ±0.34) and floor female (9.94 ±0.23). Protective antibody titer was calculated for broiler breeders who were regularly vaccinated. There were no significant differences (P≥0.05) observed in the cage versus floor housing system. Higher serum antibody titer in caged females (9.22±0.36) and floor (8.98±0.32) was calculated due to infection challenges. Morbidity and mortality were significantly affected by the cage and floor-rearing system. Frequencies of diseased birds and mortality were found higher on the floor compared to cages in the non-vaccinated group. Despite the regular vaccination sick female broiler breeders were found higher compared to cage broiler breeders. In the non-vaccinated group floor reared birds have a higher percentage of morbidity and mortality compared to cages. In conclusion cage and floor-rearing systems have no adverse effect on serum antibody titer and survivability of broiler breeders.