锌对雏番鸭淋巴器官中肥大细胞数量的影响

选择1日龄健康雏番鸭45只,随机分为3组,分别喂以每kg含锌离子20mg、40mg、200mg的饲料,饲养期为45d。于15日龄、30日龄和45日龄每组随机宰杀5只,取法氏囊、脾脏、胸腺,Carnoy法固定,甲苯胺蓝染色,显微镜观察肥大细胞数量的变化规律。结果表明：15日龄时,低锌日粮组鸭子胸腺和脾脏的肥大细胞数量均比另外两组高,（P〉0.05）,而法氏囊中低锌日粮组肥大细胞数量比另外两组明显高（P〈0.01）。30日龄时,低锌日粮组鸭子胸腺、脾脏和法氏囊中肥大细胞数量均比高锌日粮组显著增多（P〈0.05）,而与正常锌日粮组相比,差异不显著（P〉0.05）。45日龄时,法氏囊高锌日粮组与低锌日粮组和正常锌日粮组差异显著（P〈0.05）;脾脏各组间差异不显著（P〉0.05）,但高锌日粮组肥大细胞数量最多;胸腺低锌日粮组与高锌日粮组和正常锌日粮组差异极显著（P〈0.01）。因此,锌具有稳定免疫器官中肥大细胞数量的重要作用,但长时间添加高剂量锌反而会增加肥大细胞数量。

The Influence of Zinc on the Mast Cell Quantity to the Young Muscovy Duck Lymphatic Organs

In the present experiment, forty-five 1-day old ducks were chosen and randomly divided into three groups. Ducks were fed for 45 days with food that included zinc content at 20mg · Kg^-1 , 40 mg · Kg^-1 and 200mg · Kg^-1 respectively. Five ducks were randomly terminated at three intervals： 15 days, 30 days, and 45 days. The thymus gland, spleen, bursa of fabricius were removed and observed under microscope to compare mast cell quantities in the lymph organ. The results showed that the quantity of mast cells in both thymus gland and spleen of the ducks in the low zinc daily ration group are more than the other two. Results, however, were not significantly different（ P 〉 0.05 ）. In the 15-day-old ducks of low zinco group, the bursa of fabricius mast cell quantities were higher when compared to the others, at very significant difference （ P 〈 0.01 ）. At 30 days old , the mast cells quantities of ducks of low Zinc content thymus gland, spleen and bursa of fabricius all increased notably when compared to the high zinc group（ P〈 0.05 ）. When compared with the normal zinc content duck group, the 30-day-old low Zinc content ducks still had the higher mast cell quantities in the three organs, although mast cell quantities were not notable, At 45 days old,the mast cells quantities in the spleen and thymus gland in ducks of low zinc and high zinc groups were both higher than that of the normal zinc content duck group. The bursa of fabricius mast cells quantities of the high zinc content duck were the highest of the three groups and were statistically significant （ P 〈 0.05 ） as compared to both the low and normal zinc content ducks . The normal zinc content ducks had the second highest quantity of bursa of fabricus mast cell quantities followed by the low zinc content ducks. The above experiment indicates the importance of zinc in leveling off the mast cell quantity. But if ducks are fed high zinc feed for a longer period, the mast cell quantity will increase instead.