Factors associated with the determination of antibiotic activity in bovine semen.

Rosaramicin, an agent shown to be effective in vitro against ureaplasma of bovine origin was tested as an additive to bovine semen extender. Although some reduction in semen quality occurred it was still deemed satisfactory for use. In a test involving 41 cows inseminated once at estrus with rosaramicin-treated semen (162 mcg/mL) the nonreturn rate was 24% compared to a calculated average for this semen of 63% (n = 3310). The effect of centrifugation, time and temperature was examined in vitro using a combination of 150 mcg of lincomycin, 300 mcg of spectinomycin and 450 mcg of tylosin against ten strains of bovine ureaplasma. This combination has ureaplasmacidal activity and is suggested as an additive to semen extenders for the control of ureaplasma.     

牛奶中抗生素残留及其检测方法研究进展

抗生素在畜牧业中的广泛应用，不可避免地造成牛奶中残留抗生素。抗生素残留不仅危害人类健康，同时也影响牛奶的品质，造成经济损失。本文综述牛奶中抗生素残留的来源和危害、现状以及残留的检测方法。     

二甲酸钾的化学结构分析及含量测定

二甲酸钾是由2个甲酸根离子和1个钾离子组成的白色结晶体，是一种新型饲料添加剂。饲用试验结果表明，在猪日粮中添加0.6%一1.2%的二甲酸钾，可显著提高猪的增重，减少由于细菌感染造成的死亡数量(Mroz等，2003)。二甲酸钾是非抗生素饲料添加剂，但在养猪生产中起到抗生素促生长剂的作用，2001年被欧盟批准使用，是欧盟批准的第一种用于替代抗生素促生长剂的非抗生素饲料添加剂产品，其除了对仔猪的促生长和防治下痢有显著效果外，还可提高奶牛的产奶率，因此，具有广阔的应用前景。本研究对二甲酸钾的化学结构进行了研究，同时采用反相高…     

老鹳草抗菌物质提取工艺及其抗菌效果研究

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