患腹水综合征的肉仔鸡甲状腺素和器官相对重量变化的研究

240只1日龄雄性Cobb肉仔鸡随机地分为24组,每组10只。1~16组饲喂颗粒饲料,在4~7周龄时实施低温处理(13℃),来诱导腹水综合征(AS)的发生;17~20组为饲喂颗粒饲料的常温对照组;21~24组为饲喂粉料的常温对照组。结果表明,低温诱导的AS的发病率为33.89%,死亡率为19%。低温处理可使肉仔鸡体重及血清中甲状腺素(T4)浓度明显下降(P<0.05),而使肉仔鸡心脏的相对重量和血清中三碘甲腺原氨酸(T3)浓度明显上升(P<0.05)。患AS鸡的体重明显降低(P<0.05),心脏、肺、右心室及肝的重量占活体重的百分比明显升高,血细胞压积上升。由此可知,血清T3浓度的增高是腹水症发病的诱导信号,而T3和T4浓度的下降是腹水症的发生信号。

Changes of T3/T4 levels and relative organ weights in the broilers with ascites syndrome

Two hundreds and forty one-day-old male Cobb broilers were assigned to 24 groups,10 broilers for each group.The broilers in group 1~16 were fed with pellet diet and kept under the lower ambient temperature(13 ℃) from 4 to 7 weeks old to induce ascites,while the broilers in group 17~20 and 21~24 were given with the pellet and mash diets under the standard ambient temperature,respectively.The results indicated that the lower ambient temperature could induce ascites incidence(33.89%) and mortality(19%),increase plasma triiodothyronine(T_3) and relative heart weight,and decrease plasma thyroxine (T_4) concentration(P<0.05).The body weight were decreased(P<0.05),while blood hematocrit,heart weight and the percentage of right ventricle,liver and lung(divided by body weight) were increased(P<0.05).The higher plasma T_3 concentration was the signal of inducing ascites,but the lower plasma T_3 concentration was the signal of the potential incidence of ascites.