广西霞烟鸡抗马立克氏病选育报告

鸡的马立克氏病(MD)抗病育种是防制 MD 的一个新方向。经三年多的研究,采用马立克氏病病毒(MDV)强毒株攻击霞烟鸡1日龄雏鸡,选留幸存者进行繁殖,其后代未经MD 疫苗接种,以自然感染进行选择,并结合后裔攻毒测定法进行抗 MD 的选育。至三世代时,鸡抗 MD 的能力已大为提高。三世代雏鸡1日龄攻毒后,10周龄时 MD 总保护率为74%,与对照组的35%有非常显著的差异(P<0.001),其中自然死亡鸡的 MD 肿瘤阳性率为16%,与零世代的48.1%有非常显著的差异(P<0.001).与对照组的37.5%亦有显著差异(P<0.05);1日龄经火鸡疱疹病毒(HVT)疫苗免疫,14日龄以 MDV 强毒攻毒后,三世代10周龄时对 MD总保护率为96.9%,而对照组为87%。抗病核心群目前已有基本种鸡500羽。

A STUDY ON SELECTIVE BREEDING OF XIAYAN CHICKEN FOR MD RESISTANCE

Resistance selective breeding is one of the new trend for the control of Mareck's disease(MD).In a three-year study,challenge survival's breeding,unvaccinat- ed survival's breeding(through nature infection)and resistant parent's breeding(through the challenge of progeny)were combined to select a MD resistant breed of Xiayan chicken. After three generations'breeding,the unvaccinated progeny of the selected breed had a protection of 74% against the virulent strain of MD virus up to 10 weeks of age when chal- lenge at one-day-old while the chickens of the unselected breed only had a protection of 35%(P<0.001).The MD tumor occurrence in naturally dead birds of the selected breed (16%)was lower than those of the unselected breed(37.5%)(P<0.05)and those of chickens before selective breeding(48.1%)(P<0.001).When vaccinated with the com- mercial herpesvirus of turkey vaccine at one-day-old and challenged with virulent MDV strain at 14-day-old,the chickens of selected breed had a higher protection at 10-week-old (96.9%)than that of the unselected breed(87.0%).Now the number of the MD resis- tant breeder of Xiayan chicken has amounted to 500 birds.