地衣芽孢杆菌对热应激公兔甲状腺和甲状旁腺组织的影响

将成年塞北兔公兔随机分成3组:常温组、热应激组(基础日粮)和地衣芽孢杆菌组(基础日粮+1 000 mg/kg地衣芽孢杆菌),常温组温度为20?25℃,其他2个组人工模拟夏季温度.在试验期间测定血浆皮质醇含量.试验结束后测定甲状腺质量,计算甲状腺指数;观察光镜下甲状腺组织、透射电镜下甲状腺滤泡上皮细胞和甲状旁腺嗜酸性细胞...

Effects of Bacillus licheniformis on thyroid and parathyroid gland tissue in male rabbits with heat stress

To investigate the mechanism of Bacillus licheniformis in relieving heat stress in male rabbits,adult male rabbits were randomly divided into 3 groups:normal temperature group,heat stress group(basic diet)and Bacillus licheniformis group(basic diet+1000 mg/kg Bacillus licheniformis).The temperature of the normal temperature group was 20-25℃,while that of the other two groups was artificially simulated the summer temperature.The plasma cortisol content was determined during the experiment.After the test,thyroid weight was measured and thyroid index was calculated.The changes of thyroid tissue under light microscope were observed,and changes of thyroid follicular epithelial cells and parathyroid eosinophils were observed under transmission electron microscope.The results showed that Bacillus licheniformis could significantly reduce cortisol content and increase thyroid weight and index in male rabbits exposed to heat stress for 15 d(P<0.01).Bacillus licheniformis significantly improved the structure of thyroid follicles,as evidenced by a clearer membrane structure,reduced nuclear atrophy and intracellular organelle damage,and it reduced mitochondrial vacuolation in parathyroid eosinophils.Therefore,adding 1000 mg/kg Bacillus licheniformis to the diet of male rabbits could effectively reduce the content of plasma cortisol and relieve heat damage to the thyroid and parathyroid glands in heat-stressed male rabbits.Bacillus licheniformis played an important role in ensuring the normal reproduction function of male rabbits.