Observations on Corynebacterium bovis infection of the bovine mammary gland. II. Experimental infection.

Experiments are described in which lactating cows were exposed to Corynebacterium bovis either by dipping the teats in a suspension of the bacteria or by inoculating the bacteria into the teat duct or the teat sinus. All three methods readily led to 'infection' being established. The effect of these infections on somatic cell count was minor and no clinical mastitis resulted during the course of the experiments although some cases occurred subsequently. There was evidence that 44% of these infections were confined to the teat duct. Quarters excreting C. bovis in milk continued to do so during endotoxin-induced inflammation and showed a similar cellular response to that of uninfected quarters.