Intramammary infections of mammary glands in unbred heifers: absolute and differential somatic cell counts.

摘要

Lavages from 204 mammary glands of 52 unbred Holstein X Bohemian Red Pied heifers were examined. The results of bacteriological examination were negative in 163 (78.4%) glands. Minor pathogens, mostly coagulase-negative staphylococci, were demonstrated in 34 (16.3%) glands. Five glands (2.4%) were infected by environmental pathogens. Two glands (1%) were infected by contagious agents. Absolute somatic cell counts in lavages, standardized to a volume of 20 ml, for the above 4 categories were 0.966,2.138, 3.267 and 3.138 X 106/ml, respectively. Macrophages predominated in differential somatic cell counts both in the noninfected (66.6%) and in the infected (62.2%) glands. The counts of polymorphonuclear leukocytes were higher in the infected than inthe noninfected glands (14.2 vs. 4.5%). On the other hand, lymphocyte counts were higher in the noninfected than in the infected glands (26.5 vs. 13.2%). It is concluded that the juvenile mammary gland of unbred heifers is a suitable object for health tests in heifers before their incorporation into breeding. Catheterization and lavage of mammary gland sinuses yield suitable means for sampling for both bacteriological and cytological examinations.