Abstract

Infectious bursal disease is an acute and highly contagious viral disease of chickens. it is one of the most economically important viral diseases that threatens the survival of the poultry industry in Nigeria. Clinico-pathological changes that could lead to high morbidity and mortality caused by infectious bursal disease have been linked to changes associated with oxidative stress. This study investigated the effects of selected antioxidants on antibody response, morbidity and mortality rates in chickens infected with infectious bursal disease. An experiment was conducted to determine the combined effects of vitamin E-selenium complex, vitamin C and, E-selenium complex and vitamin C on the antibody responses of Novagen cockerels to intermediate infectious bursal disease vaccine; investigate the effects of the antioxidants on clinical signs, morbidity and mortality rates in infectious bursal disease-vaccinated and non-vaccinated birds experimentally infected with a very virulent infectious bursal disease virus. Results showed that, cumulative mean antibody titre of birds supplemented with vitamin C (8,612.6 ± 2370.28) was significantly (p <0.05) higher than group supplemented with vitamin E-selenium (8,053.7 ± 3053.07), positive control group (7,769.5 ± 3044.70) and group supplemented with their combination (7,509.6 ± 1155.08). Morbidity rates in infectious bursal disease vaccinated, and non-vaccinated birds in group supplemented with vitamin E-selenium was 38%, and 74%, respectively; vitamin C, 36%, and 68%, respectively and vit E-Se combined with vitamin C, 30%, and 66%, respectively, was lower when compared to positive control groups 40%, and 82%, respectively. Mortality rates in infectious bursal disease vaccinated and non-vaccinated birds in group supplemented with vit E-Se was 8%, and 54%, respectively; vitamin C, 6%, and 46%, respectively, vit E-Se combined with vitamin C, 6% and 50%, respectively, was lower when compared to positive control groups 8%, and 62%, respectively. It was concluded that vitamin C supplement used in drinking water of Novagen cockerels improves antibody titre to intermediate infectious bursal disease vaccines, reduced morbidity and mortality rates in cockerels infected with a very virulent infectious bursal disease virus. It is therefore recommended that vitamin C should be supplemented in poultry drinking water from day 1-50 of age to improve antibody response to infectious bursal disease vaccine, reduce morbidity and mortality rates associated with a very virulent infectious bursal disease virus infection in chickens.

Keywords

cockerels, antioxidants, infectious bursal disease virus, antibody, morbidity, mortality