Effect of Exogenous Progesterone on the Bovine Corpus Luteum of Early Pregnancy

Abstract
The effects of injecting progesterone in starch suspension on day-3 5, -42, and -49 of pregnancy were studied in nine heifers. Ten uninjected heifers served as controls, animals from both groups being slaughtered on day-56 of pregnancy. Progesterone had. no significant effect on corpus luteum weight; the mean weight for treateds was 4.85 gm. as compared to 5.41 gm. for controls. A significant (P< 0.05) decrease in the progestogen content from 84 mcg. per gland in the controls to 36 mcg. in the treated group resulted from injections of progesterone. Histological examination of the corpora lutea from untreated heifers indicated a marked difference from the histological picture present at day-14 of the estrual cycle in other studies. Copyright © . .