Marek's Disease (MD) is a neoplastic disease of chickens and remains as a chronic infectious disease that threatens the poultry industry. Improving genetic resistance to MD in poultry is an important long-term goal, which would significantly augment the current control measures against MD and eventually reduce the annual economic loss. In this study, survival patterns of F2 birds from 2 reciprocal crosses were compared to examine possible difference in survival between the reciprocal crosses in response to MD virus (MDV) challenge. A total of 246 and 224 F2 chicks derived from reciprocal crosses of lines 63 × 72 and lines 72 × 63, respectively, were sampled from an MDV challenge trial and survival days were recorded from the MDV-inoculation date to the end of experiment. Statistical analyses, including Principal Component Analysis (PCA) followed by a cox-regression model, showed there was no significant difference in survival days between reciprocal crosses (P > 0.05). To the best of our knowledge, this is the first MD survival study on reciprocal crosses of 2 genetically diversified lines of chickens differing in MD resistance. This report documented the experimental evidence that the genetic lineage of grandparental (maternal or paternal) effect on survival days was minimal, if present at all.
Keywords: Marek's disease; grandparental effect; reciprocal crosses; survival analysis.
© 2019 Poultry Science Association Inc.