不同氨气浓度对肉鸡福利的影响

Effect of Different Ammonia Concentrations on Broiler Welfare

试验旨在探讨养殖环境中氨气不同程度的聚集对肉鸡福利状况的影响。本研究选择21日龄健康状况良好、体重相近(743.6±8.2g)的爱拔益加(AA)肉鸡320只,平均分在4个呼吸舱中饲养,网上平养,舱内氨气浓度分别控制在0、25、50、75mg·kg-1。42日龄时对各处理肉鸡的福利状况进行评估。结果显示,不同浓度的氨气处理对肉鸡死亡率与羽毛清洁度评分无显著影响(P>0.05),但显著影响了肉鸡的脚垫评分、跗关节评分及步态评分(P<0.05)。氨气浓度为75mg·kg-1处理的鸡只脚垫及步态评分显著高于其他3个处理(P<0.05)。暴露于75mg·kg-1氨气浓度下的肉鸡跗关节损伤程度显著高于50mg·kg-1处理(P<0.05),50mg·kg-1处理下的肉鸡跗关节损伤程度显著高于0和25mg·kg-1处理(P<0.05)。由此可见,舍内氨气的积聚会影响肉鸡的福利水平。随着氨气浓度的升高,肉鸡出现羽毛污损、足跗关节及脚垫感染、跛行、行走不稳等状况的几率和程度加大。为保证肉鸡的健康和福利,鸡舍内氨气浓度最好控制在25mg·kg-1以内。

The experiment was designed to investigate the effect of different ammonia concentration on broilers＇ welfare condition in the breeding environment.Three hundred and twenty healthy AA broilers 20 days old with similar weight（（743.6±8.2）g）,were randomly divided into 4respiratory chambers,and raised on the net.The ammonia concentrations in the 4chambers were controlled at 0,25,50,75mg·kg-1,respectively.The broilers＇ welfare situation in 4treatments was assessed at the age of 42 day.The results showed that different ammonia concentrations had no significant effect on broilers＇ mortality and feather cleanliness score（P〉0.05）,but significantly influenced the foot pad damage score,elbow damage degree score and gait score（P〈0.05）.The foot pad damage score and gait score of broilers under 75mg·kg-1 ammonia concentration were significantly higher than the other treatments（P〈0.05）.The broilers＇ elbow damage degree score under 75mg·kg-1 ammonia concentration was significantly higher than the 50mg·kg-1 treatment（P〈0.05）,and the 50mg·kg-1 treatment was significantly higher than the0 and 25mg·kg-1 treatments（P〈0.05）.In conclusion,the accumulation of ammonia could affect the broilers＇ welfare.As ammonia concentration rise,the broilers have higher probability anddegree of feathers dirt,elbow and foot pad infection,lameness and unsteady gait.In order to ensure the broilers＇ health and welfare,the ammonia concentration in the henhouse have better be controlled within 25mg·kg-1.