Abstract

---

A study involving 35 Friesian x Indigenous (CROSSBRED) and 35 Indigenous (INDIGEN) nonlactating multiparous cows was conducted in Mazabukato investigate the effect of Prostaglandin F2α (PGF2α) on estrus synchronization. On day 0, the cows were intramuscularly injected with 2 ml of PGF2αand observed for estrus. On day 11, the injection was repeated in those cows that did not respond to the first injection. The Estrus Response (%) and the Response Time (hours) were statistically compared between the two groups of cows. Twelve (34%) CROSSBRED and five (14%) INDIGEN cows came into estrus following administration of PGF2α. While the Estrus Response was low in both groups of cows, the number of responsive CROSSBRED cows was numerically higher than that of INDIGEN cows. The Response Time was, however, similar (P>0.05) in both groups of cows. It is concluded that estrus synchronization with PGF2αhad more effect in CROSSBRED cows than in INDIGEN cows. For practical purposes, however, the apparent greater effect of PGF2α in CROSSBRED cows was not significant to warrant recommendation. This technique is therefore not recommended for smallholder dairy farmers under the current management levels. Further research on how to improve the effectiveness of estrus synchronization is recommended.

---