肉用母牛乳房内感染的发生率及影响

Prevalence and effects of intramammary infection in beef cows.

作者信息

Watts J L, Pankey J W, Oliver W M, Nickerson S C, Lazarus A W

出版信息

J Anim Sci. 1986 Jan;62(1):16-20. doi: 10.2527/jas1986.62116x.

DOI:10.2527/jas1986.62116x

Abstract

Prevalence and effects of intramammary infection in 322 beef cows was determined during three calving intervals. Intramammary infection was confirmed in 37% of cows and 18.1% of quarters. Coagulase-positive staphylococci accounted for 17.9% of infections with Staphylococcus aureus isolated from 7.1% of cows. Coagulase-negative staphylococci and micrococci accounted for the remainder of infectious organisms. Butterfat and total protein levels were reduced 27.3 (P less than .05) and 25.5% (P less than .01), respectively, in milk from quarters infected with S. aureus. Somatic cell counts were elevated (P less than .001) with 3,827 X 10(3) cells/ml for S. aureus-infected quarters as compared with 555 X 10(3) cells/ml for uninfected quarters. Somatic cell counts were negatively correlated with 210-d calf weaning weights. Staphylococcus aureus-infected cows weaned calves weighing 19.1 kg less (P less than .01) than uninfected cows. At a present market value of $1.65/kg, economic losses were placed at $31.43/calf from cows infected with S. aureus in one or more quarters.

摘要

在三个产犊间隔期内，对322头肉用母牛的乳房内感染情况及其影响进行了测定。结果发现，37%的母牛和18.1%的乳腺区存在乳房内感染。凝固酶阳性葡萄球菌占感染的17.9%，从7.1%的母牛中分离出金黄色葡萄球菌。凝固酶阴性葡萄球菌和微球菌占其余的感染性生物体。感染金黄色葡萄球菌的乳腺区所产牛奶中的乳脂和总蛋白水平分别降低了27.3%（P<0.05）和25.5%（P<0.01）。金黄色葡萄球菌感染的乳腺区体细胞计数升高（P<0.001），每毫升达3827×10³个细胞，而未感染的乳腺区为555×10³个细胞/毫升。体细胞计数与210日龄犊牛断奶体重呈负相关。感染金黄色葡萄球菌的母牛所产犊牛断奶时体重比未感染的母牛轻19.1千克（P<0.01）。按目前每千克1.65美元的市场价值计算，一个或多个乳腺区感染金黄色葡萄球菌的母牛所产犊牛每头造成的经济损失为31.43美元。