环境低温和T_3致肉鸡腹水、肺动脉高压和肺微细动脉肌型化

Ascites,Pulmonary Hypertension and Muscularization of Pulmonary Arterioles Induced by Cool Environmental Temperature and Dietary T_3 in Broilers

21 0羽 AA商品肉鸡随机分为 A、B、C 3个组 ,常规饲养。 1 4日龄后 A组鸡正常对照 ,而 B、C组鸡舍温按每日1～ 2℃由 2 5℃逐步降至 1 2℃ ,同时 C组在日粮中按 1 .5 mg/ kg的剂量添加甲状腺素 T3以诱发肉鸡腹水综合征 ( as-cites syndrom e,AS)。结果表明 :低温和 T3能显著增加 AS发病率、红细胞压积 ( PCV)值、右心室与全心室重量比( RV/ TV)、平均肺动脉压 ( m PAP)和厚壁末梢血管百分率 ( TWPV % ) ( P<0 .0 1 )。从而揭示了环境低温和

Two hundred and ten 1-day-old AA commercial broilers were divided randomly into control(Group A) and two experimental groups(B and C).Broilers in different experimental groups and group A were fed with a normal diet before 14 days of age.In different experimental groups,broilers were subjected to a change of temperature by lowering 1-2℃ per day from 25℃(day 14) down to 12℃,and then maintained at this ambient temperature until 7 weeks of age.At the same time,1.5 mg/kg 3,3,5-triiodothyronine(T_3) in the diet was added to in group C in order to induce ascites syndrome(AS).The result indicated that the lower ambient temperature and dietary T_3 significantly increased AS incidence,the packed cell volume(PCV),the ratio of right ventricle to total ventricle(RV/TV),the mean pulmonary arterial pressure(mPAP),and the percentage of thick-walled peripheral lung vessels(TWPV%)(P<0.01).It might be concluded that the muscularization of pulmonary arterioles and the pulmonary hypertension had occurred in broilers with ascites syndrome induced by cool environmental temperature and dietary T_3.