Factors Affecting the Incidence of Cystic Ovaries in a Herd of Holstein Cows

Abstract

Ment of the relatonship between the pituitary gland and the ovary. Garm (3) listed infections of the genital organs, high protein diet, insufficient range feeding, hereditary predisposition and high milk yield as potential etio- logical factors. He concluded from his own studies that infections of the genital organs did not seem to play any part, but that nymphomania is a multiglandular syndrome for which an hereditary predisposition usually exists. He also saw evidence in his material of a positive relationship between nymphomania and high milk yield. The present study is an examination of some of the possible causes of variation in the incidence of cystic ovaries in the purebred Holstein herd of the Pabst Farms, Oconomowoe, Wis. The incidence of the cystic condition in this herd is judged to be quite comparable to that in other herds of a similar level of milk production. This particular herd was studied because of the unique thorough- ness of daily observations on the animals and the completeness of the reproduction records. These records covered the interval from July, 1932, to November, 1942, during which time the care of the herd was under the direction of the late Howard Clapp. The careful observations and the detailed records used in this study are the work of this outstanding herd manager. They have been made available for this study through the courtesy of Fred Pabst. Records on 341 cows were collected during this interval. The number of service periods these cows spent in the herd ranged from one to 13. The occur-