[The selecting experiment of resistance to Marek's disease of chicken]

The Marek's Disease is an acute infectious disease in poultry production. The selecting experiment through blood-group gene inspection of adult parents and attack-test by using of Marek's Disease virus (MDV) for offspring chicks was carried out. The results showed as follows: (1) The rates of positive reaction by No. 614 blood-group gene inspection of adult parents in four generations were increased due to generation increase, as F0-68.8%, F1-77.3%, F2-81.8% and F3-90.5%. (2) In the attack-test by using of MDV at 10 days of age of chicks the mortalities of the experimental group at 60 days of age of chicks whose parents have positive reaction by No. 614 blood-group reagent detect in F2-F4 generations were 25.8%, 69.2% and 29.4% respectively, while the mortalities of the control group at same age of chicks whose parents have negative reaction were 30.6%, 81.0% and 52.9% respectively. These differences of mortality were significant (P < 0.01 or P < 0.05). (3) The rates of pathological change of 9 viscera tumor of the experimental group chicks in F2-F4 generations were 87.6%, 83.3% and 58.8% respectively, while chicks in the control group were 88.1%, 84.5% and 70.6% respectively. Except individual generation and viscera, these differences between the experimental group and the control group were almost not significant (P > 0.05). The experimental results and genetic control of resistance to Marek's Disease are discussed in this paper. The new strain of chicken resistant to Marek's Disease will be bred.