[The relationship between bovine clinical mastitis at the time of parturition and retained placenta]

868 parturitions were examined to determine the relation between the clinical mastitis around partition and the loosening process of the placenta in the bovine. The occurrence of mastitis in heifers and cows around parturition was 18.7%. The frequency of retained placenta in animals with mastitis was significantly higher (p less than 0.01) than that in animals without mastitis influenced the loosening process of the afterbirth. The results support an hypothesis, that mastitis and retentio secundinarum can regard as signs of the decrease in the activity of the immune system.