奶牛隐性乳房炎的流行病学调查

Epidemiological Survey of Recessive Mammitis in Dairy Cow

为了解开封市奶牛隐性乳房炎的发病情况,选择年龄2.5~10岁,胎次为1~8次的250头健康荷斯坦牛970个乳区进行连续检测,结果表明：隐性乳房炎的发病率在不同牛舍间差异不显著;在2—4月份隐性乳房炎的头阳性率和乳区阳性率均随着月份的增加而不断下降;在各胎次均有发生,且随胎次的增加头阳性率增加;随着泌乳期的延长乳区阳性率增加;日产奶量≤20 kg的奶牛的隐性乳房炎感染率高于日产奶量≥20 kg的奶牛。

970 mammary regions of 250 healthy 2.5～10 years old Holstein cattle and 1～8 gravidities were continuously determined to know the morbidity of recessive mammitis in Kaifeng city.The results showed that there was no significant difference in morbidity of recessive mammitis among different cowhouses,the positive rate of dairy cows with recessive mammitis and the positive rate of mammary region continuously reduced with month increase from February to April,the positive rate of dairy cows increased with gravidity increase,the positive rate of mammary region increased with extension of lactation period,and the infection rate of dairy cows with ≤20kg daily yield was higher than that of dairy cows with≥20kg daily yield.