The Research Of Disease Resistance-Associated Parameters To Coccidian And Selection In Jinghai Yellow Chickens

From a long time, the main target of poultry breeding was concentrated on improving economic traits, various kinds resource were most used to enhance the performance trait associated with the economic profit. Meanwhile, the other physio-functions were degraded, including immune response function. The result is that the poultry were more sensitive to disease while the performance traits were improved. It can't solve the problems at basic, although the medicine,vaccine were unceasing improvement. It should initiate with breeding, a significant study aspect is bolting and cultivating of disease resistance animal strains.To determine an optimal dose for coccidial inoculation and to evaluate genetic resistance in jinghai yellow chickans, broilers were inoculated with different doses of Eimeria tenella oocysts. Postinoculation (PI) observed pathological changes of the inoculated broilers, calculated fecal oocyst shedding from postinoculation (PI) 6 to 9, and body weight gain,concentrations of plasma NO,β-carotene were measured at three different periods (pro-inoculation,PI6,PI9 ).The purpose is to establish the foundation of disease resistance breeding for jinghai yellow chicken. The results showed significant dose and sex effects on most parameters and interaction between dose and sex in someparameters.1. The fecal oocyst shedding was positively correlated to inoculation doses; there are difference between male and female in fecal oocyst shedding; the fecal oocyst shedding reduced from the day 6 postinoculation..2. The body weight gain was negatively correlated to inoculation doses; there are no significant difference between male and female in body weight gain, but the body weight gain of female is lower the the male. 3.The concentrations of plasma NO were positively correlated to inoculation doses; there are no significant difference between male and female, the concentration NO of in male's plasma was slightly lower than female's.; the concentrations of plasma NO at days 6 and 9 postinoculation were higher than pro-inoculation.4.The concentration of plasmaβ-carotene were negatively correlated to inoculation doses; there are significant difference between male and female, the female's concentration of plasmaβ-carotene were lower than the male's; the concentration of plasmaβ-carotene at days 6 and 9 postinoculation were lower than pro-inoculation.5.The correlation of all parameters: The Body weight gain of postinoculation 6-9 and 0-9,plasmaβ-carotenoid of the days 6 and 9 postinoculation were negatively correlated to fecal oocyst shedding, plasma NO was positively correlated to fecal oocyst shedding; the body weight gain of postinoculation 6-9 and 0-9 were positively correlated to plasmaβ-carotenoid of the days 6 and 9 postinoculation, but negatively correlated to plasma NO.6.Comparison of the two generations, fecal oocyst shedding and concentration of plasmaβ-carotene in the first generation were higher than the second generation, body weight gain and concentration of plasma NO in the first generation were lower than the second generation. It showed immunity and resistance to coccidian of the second generation were higher than the first generation.