地衣芽孢杆菌对热应激公兔精液品质及激素水平的影响

Effects of Bacillus licheniformis on the semen quality and hormonal levels of male rabbits with heat stress

选择体质量基本一致、性欲旺盛的健康公兔25只,设常温对照组、热应激对照组(饲喂配合日粮)和热应激试验1~3组(分别在配合日粮中添加地衣芽孢杆菌500,1 000,1 500mg/kg),热应激温度控制在33~35℃。测定采食量和体质量;采用动物精子测定仪检测精液品质;放射免疫法测定血浆FSH、LH、TSH、T、T_3、T_4含量。结果显示:日粮中添加1 000mg地衣芽孢杆菌采食量除第10,15天显著高于热应激对照组外,其他日期差异不显著;体质量略高于热应激对照组,较常温对照组低;对采精量无明显影响,10d后精子密度和精子活力极显著低于常温对照组,极显著高于热应激对照组,精子畸形率明显降低;对血浆FSH影响不明显,能提高热应激公兔前20d血浆LH和TSH浓度,提高血浆睾酮(T)和T_3、T_4含量。结果表明:在公兔日粮中添加1 000mg/kg地衣芽孢杆菌能够短期缓解热应激,提高精液品质,有升高血浆LH、TSH、T、T_3、T_4浓度的作用,并对地衣芽孢杆菌的添加量有剂量依赖性。

To study the effects of feeding Bacillus licheniformis on the semen quality and male rabbits with heat stress,25 sexually active male rabbits with equal body weight were randomly di- vided into 5 groups of 5 each. The normal control group and heat stress control group were fed with the complete feed,the 3 heat stress test groups were fed with the basic die supplemented with Bacillus licheniformis（500,1000 and 1500 mg/kg,respectively）. Heat stress temperature was controlled within 33-35℃. Feed intake,body quality and semen quality was measured respec- tively,and follicle stimulating hormone（FSH）, luteinizing hormone（LH）, thyroid stimulating hor- mone （TSH）, testosterone （T）, triiodothyronine （T3） and thyroxine （T4） in plasma were deter- mined with RIA. The results showed that supplementation of 1000 mg/kg Bacillus licheniformis could improve the feed intake at the 10th and 15th day significantly compared with the heat stress control group, but had no difference at other days. The additive could increase the body quality slightly compared with heat stress control group, and reduced the body quality compared with normal control group,but had no effect on the quantity of semen production. The spem concentra- tion and viability in added group was lower than normal control group, and higher than heat stress control group significantly,the sperm deformation rate reduced significantly after 10 days. 1 000 mg/kg supplementation could increase the plasma LH, TSH of heat stress male rabbits first 20 days, and T, T4 and T3 content raised, but had no obvious effect on the FSH. Adding 1 000 mg/kg Bacillus licheniformis in the diet of male rabbits could relieve the heat stress in the short term,improve the semen quality, in-crease the concentration of plasma LH, TSH, T, T3 and T4, and with dose-dependent.