皮质醇混饲投喂对黄颡鱼幼鱼生长及外周血细胞的影响

采用皮质醇混饲投喂的试验方法,模拟自然条件下的慢性应激,观察和分析了应激激素皮质醇对黄颡鱼(Pelteobagrus fulvidraco)幼鱼生长和外周血细胞的效应。试验组饲料中皮质醇添加剂量为100 mg/kg,日投饵率为3%,试验期5周。结果表明:(1)外源皮质醇通过减少肠道黏膜皱褶和促进糖异生作用使黄颡鱼幼鱼增重受阻;(2)外源皮质醇使黄颡鱼幼鱼外周血白细胞数量显著减少、淋巴细胞百分比显著降低,但是中性粒细胞和单核细胞百分比则呈上升趋势;(3)外源皮质醇能促进红细胞增生,增加黄颡鱼幼鱼外周血红细胞数量。

The Effects of Dietary Intake of Cortisol on the Growth and Circulating Blood Cells in Fingerling Yellow Catfish(Pelteobagrus fulvidraco)

Method of incorporation of cortisol in the diet,simulating natural chronic stress,was used to study the growth and circulating blood cells in the cortisol-fed fingerling yellow catfish(Pelteobagrus fulvidraco).Cortisol was incorporated into diet in a concentration of 100 mg/kg.The cortisol containing diet was administrated at 3% of the body weight per day for five weeks.The main effects of long-term oral administration of exogenous cortisol included:(1)Reduced growth in fingerling yellow catfish by reduction of intestinal mucosal folds and enhancement of gluconeogenesis;(2)Reduced the number of circulating white blood cells and the lymphocyte percentage in differential leucocyte counting(DLC),but increased the percentage of neutrophils and monocytes in DLC.(3)Increased the number of circulating red blood cells(RBC)and enhanced RBC proliferation.