Influence of Progesterone Treatment on Post-Partum Reproductive Activity in Beef Cattle

Publisher Website
Google Scholar
Abstract
The effect of a single post-partum injection of progesterone (1 mg. per lb. body weight, subcutaneously, 14 days after calving) on the intervals from calving to involution of the uterus, first ovulation, and first heat were studied in 62 cows (44 Angus and 18 Shorthorn). Treatment had no effect on the interval from calving to involution of the uterus, 41.7 days for treated as compared to 41.4 days for the controls. The average post-partum interval to first ovulation was significantly longer in the treated than in the untreated group (61.1 vs. 41.7 days). The average intervals from calving to first heat for the treated and untreated groups were 83.0 and 65.6 days, respectively. The difference was significant. Although progesterone treatment tended to delay ovarian activity and consequently the expression of heat after calving, it did not decrease the variability of any of the intervals studied. Treatment had no significant effect on conception rate. For 27 treated and 25 untreated cows bred at first heat the average conception rates were 74.1% and 80.0%, respectively. Copyright © . .

This publication has 0 references indexed in Scilit: