实验性雏鸭锌中毒症的病理学研究

1日龄天府肉鸭健雏100只随机分为2组，分别喂以止常对照(Zn100mg／kg日粮)和锌中毒(Zn1300mg／kg日粮)日粮4周，进行系统的病理学研究。中毒鸭13d出现症状，18只死亡。尸检主要见腿部肌肉色白或灰白色，外观似蜡样；肌胃平滑肌色淡灰白；消化道充满黑褐色煤焦油样内容物。光镜下，骨骼肌纤维肿胀变性坏死；心肌和肌胃平滑肌局灶性坏死；胸腺、腔上囊、脾脏淋巴细胞减少。电镜观察，免疫器官淋巴细胞线粒体肿胀、嵴断裂。血液病理学变化主要是碱性磷酸酶活性、血清总蛋白与球蛋白含量以及红细胞总数和血红蛋白含量降低，血清谷丙转氨酶活性和锌含量升高。结果表明，高锌对鸭可产生明显的毒害作用。文中还对发病机理进行了探讨。

Studies on Pathology of Zinc toxicity in Ducklings

100- day- old Tianfu ducklings were divided into two groups,and fed on diets as follow:Zn toxic (1 300 mg/kg diet) and controls (100 mg/kg diet) for four weeks.Zn toxic ducklings showed symptoms at the age of 13 days.All were ill in the end of experiment and 18 died.At necropsy,muscles in the leg were white or greyish-white.The white stain appeared in the section of smooth muscle of gizzard.The digestive tract was full of the black- brown substance.Histopathologically,the skeletal muscle of legs was degenerated and necrotic.The cardiac muscle and smooth muscle of the gizzard showed local necrosis.Lymphocytes of the immune organs was depleted.Ultrastructurally,the mitochondria of lymphocytes were swelled.The serum alkaline phosphatase (AKP) activities,serum total albumen,globulin contents,red blood cells and hemoglobin contents were much lower in Zn toxic group than those in the control group (P<0.05).In Zn toxic ducklings,the serum glulamic- pyruvic transaminase and serum Zn concentrations were much higher (P<0.01).Results demonstrated that dietary high zinc caused toxic injure in ducklings.