日粮锌、硒添加量对肉鸡肠黏膜结构及上皮内淋巴细胞和杯状细胞数量的影响

为了探讨微量元素锌和硒互作对肉鸡肠道黏膜屏障结构的影响,将24只1d龄从肉鸡随机分3组,分别饲喂添加有高锌高硒(锌1000mg/kg、硒5mg/kg)、低锌低硒(锌34mg/kg、硒0．08mg/kg)和常锌常硒(锌50mg/kg、硒0．15mg／kg)的日粮45d后,观察小肠黏膜上皮细胞、上皮内淋巴细胞、杯状细胞的形态结构变化。结果表明：高锌高硒或低锌低硒组肉鸡的肠黏膜结构有明显的损伤,表现为肠黏膜上皮细胞萎缩,上皮内淋巴细胞数量和杯状细胞数量减少;尤其是高锌高硒组的损伤最为严重。而常锌常硒组肉鸡肠黏膜结构和上皮内淋巴细胞数和杯状细胞数正常。结论：日粮中按锌50mg/kg、硒0．15mg/kg的比例添加,对于维持肠道黏膜的正常屏障结构是合适的。过高或过低的锌和硒对肠黏膜有毒性作用,破坏其屏障功能;而且高锌和高硒可相互促进以增强其毒性作用。

Effect of Different Quantities of Zinc and Selenium Level in Diet on the structure of Mucous Epithelium and Intraepithelial Lymphocyte and the Goblet Cells in the Small Intestine of Broiler

To explore the effect of trace elements zinc, selenium and their interaction on the gut barrier function in the broiler, twenty-four one-day-old AA broilers were divided into three groups, and were fed with the different diets including high zinc-selenium (Zn 1 000 mg/kg, Se 5 mg/kg), low zinc-selenium (Zn 34 mg/kg, Se 0.08 mg/kg), and normal zinc-selenium (Zn 50 mg/kg, Se 0.15 mg/kg), respectively. After forty-five days, the broilers were killed and the structure of mucous epithelium in the small intestine was observed. The results showed that in two groups of high zinc-selenium and low zincselenium, the epithelium of mucasa was atrophy and defluxion, especially in the high zinc-selenium group. The numberof intraepithelial lymphocyte and the goblet cells decreased. But the structure of mucous epithelium, the number of intraepithelial lymphocyte and the goblet cells were normal in the normal zinc-selenium group. This study indicated that the supplementary level of selenium at 0.15 mg/kg and zinc at 50 mg/kg in diet should be an appropriate ratio which would keep the normal gut barrier function in the broiler.