Bacteriological Studies of Uteri of Clinically Normal Cows of Low Fertility

Abstract

This study was undertaken to determine if the uteri of clinically normal cows of low fertility contained microorganisms at 16 days postbreeding, a stage immediately followed by a high incidence of embryonic death. Sixty-nine cows were slaughtered, the uteri removed aseptically, and flushed with 15 ml of 0.1% tryptone broth. Various media were inoculated with the recovered fluid and incubated in air, in 15% CO2 and reduced air, and in an anaerobic jar. Triturated endometrial tissue of 35 animals in the study was similarly cultured. Microorganisms were recovered from the uteri of eight (11.6%) of the 69 repeat-breeders. A yeast, Candida krusei, was isolated from four uteri, an Escherichia species from one, a Pseudomonas from one, Brucella abortus from one, and a paracolon from one. Embryos were recovered from 31 of 62 uteri from cows with anatomically normal reproductive tracts; three embryos were recovered from the eight infected uteri. Vaginal mucus samples were obtained from 35 of the animals at from 11 to 13 days postbreeding and at slaughter. One cow had a positive mucus agglutination test for Vibrio fetus. Serum agglutination-lysis tests for leptospirosis were made on all animals. None was positive. Microbial infection apparently accounted for few of the embryonic deaths in these clinically normal animals of low fertility. It must be emphasized that this is a selected kind of cow and the findings of this study may have little bearing on the broad role of microorganisms in lowered fertility in cattle.