慢性氨气暴露对肉鸡NK细胞杀伤活性和血清新城疫抗体效价和溶菌酶的影响

为探讨氨气对肉鸡免疫功能的影响,选择240只1日龄AA肉公鸡,随机分成4个处理组,分别饲养在4个独立的、环境可控制的实验舱内。4个环控仓氨气浓度设计为0～3周龄分别为0、13、26mg/kg和52mg/kg;3～6周龄分别为0、20、40mg/kg和80mg/kg。结果表明:高浓度氨气暴露3周和6周,肉鸡血清溶菌酶均表现降低,其中3周龄溶菌酶降低较显著(P<0.05);肉鸡氨气暴露6周后,NK细胞杀伤活性显著下降(P<0.05),新城疫弱毒疫苗免疫效能显著降低(P<0.05)。这一结果表明肉鸡暴露在高浓度氨气环境中,其免疫功能会表现降低。

Effects of Chronic Ammonia Exposure on Natural Killer Cell Activity,Newcastle Disease Antibody Titer and Serum Lysozyme Levels of Broiler

The present study was carried out to investigated the effect of chronic ammonia exposure on natural killer cellactivity, Newcastle Disease antibody titers and serum lysozyme levels of broiler.Two hundred and forty male commercial AA broilers at 1 day of age were randomly allotted to one of four treatments with six pens per treatment and ten broilers per pen.Each treatment was placed in a separated, environmentally controlled chamber(four chambers).Anhydrous ammonia was metered continuously into the chambers to maintain 24-h levels of 13, 26, or 52 mg/kg ammonia from 0 to 3 week.At 22 day of age, ammonia concentration in all chambers was adjusted in turn to 20, 40, or 80 mg/kg and maintained until 6 weeks of age.No ammonia was added to the remaining chamber to maintain near 0 mg/kg(the control).The results showed that high levels of ammonia(>50 mg/kg) could significantly decrease serum lysozyme levels at ages 21 and 42 days and ND antibody titers at age 42 day(P < 0.05).Chronic ammonia exposure showed a significant(P < 0.01) decreased effect on natural killer cell activities.In conclusion, chronic ammonia(> 50 mg/ kg) exposure reduced immunocompetence of broilers.