ABSTRACT
The potential benefits of local chickens to the rural economy is compromised annually by regular outbreaks of Newcastle Disease (ND). Every year over 80% of the local chicken population is lost to ND, depriving the rural people of the much needed protein and income from chicken. In an effort to reduce the effect of Newcastle Disease on local chicken production, this study was conducted to determine if there is variation in the genetic resistance to NDV in three local chicken ecotypes of Ghana. Local chicken sampled from the Forest, costal savanna and Interior savanna eco-zones were bred and their offspring challenged with the La Sota strain of the Newcastle Disease Virus (NDV) at four weeks old. Antibody titre levels were determined using ELISA before infection and ten days post-infection. Chickens from the Forest ecozone were found to have significantly higher antibody titres (p<0.05) against the La Sotastrain of the virus. Chickens from the Interior Savannah ecozone had significantly higher body weight and growth rate than the other ecotypes. Heritability for growth rate (before and after challenge) and antibody titres (Log10 titre and average titre) were found to be 0.9322 ± 0.1448, 0.8909 ±0.1437 and 0.2096 ± 0.0850 0.2635 ± 0.0960, respectively. Genetic correlation between both traits was 0.37. From the study, local chicken ecotypes showed genetic differences in immune response to NDV. This study provides evidence substantial enough for selection for improved antibody production against NDV and higher growth rates among local chicken ecotypes. Thus, selection for improved growth rate will lead to a correlated in response ND resistance.
