The relationship between the number of mastitis pathogens placed on the teats of dry cows, their survival, and the amount of intramammary infection caused

Abstract

Summary: When the teats of dry cows were dipped in a culture containing 3–25 × 10⁶ mastitis organisms/ml only 25% of 71 quarters acquired an intramammary infection. Small numbers of organisms applied to teats caused negligible infection. The degree of contamination also determined the survival of the organisms on the exterior of teats, which was much greater at the teat apex than on the body of the teat.There was no evidence that swabbing the teat apex increased the chance of intramammary infection. Washing the udder of infected cows with a disinfectant increased the chance of recovering the organisms from the teat skin.