ASSOCIATION OF ABNORMAL UTERINE DISCHARGE WITH NEW INTRAMAMMARY INFECTION IN THE EARLY POSTPARTUM PERIOD IN MULTIPAROUS DAIRY-COWS

The association of abnormal uterine discharge with the development of intramammary infection (IMI) was studied in 62 multiparous Holstein co ws during the nonlactating period and from lactation days 3 through 30 , Duplicate milk samples were obtained from each mammary gland at appr oximately day 30 of the nonlactating period. Milk samples for bacterio logic culture also were obtained from each gland from all cows at the end of the previous lactation, at parturition, and on a minimum of 7 a dditional dates during the first 30 days of lactation. Beginning after parturition and continuing once weekly for 4 weeks, each cow was exam ined, using a vaginal speculum to visually estimate the quantity of ab normal uterine discharge in the vagina. Additionally, uterine swab spe cimens were obtained for aerobic bacteriologic culture. Cows were allo tted to groups on the basis of the maximal amount of abnormal uterine discharge observed at any 1 of the 4 examinations. Cows in group 1 had normal discharge or < 30 ml of abnormal discharge; in group 2, greate r-than-or-equal-to 30 ml of abnormal discharge, observed only on exami nation by vaginal speculum; and in group 3, greater-than-or-equal-to 3 0 ml of abnormal discharge visible externally. A difference was not de tected in the development Of new IMI in the nonlactating period betwee n cows that subsequently developed uterine discharge and those that di d not. Although significant differences were not found, a tendency for lactating cows with abnormal uterine discharge to be at increased ris k for developing new imi was observed. Direct associations were not fo und between aerobic bacterial species isolated from the uterus and spe cies isolated from glands with newly developed IMI during lactation. T his lack of association indicated that development of IMI in lactation was not likely a direct result of teat-end exposure to bacteria origi nating from the uterus.