Is estradiol valerate an alternative to estradiol benzoate in promoting the synchronization of ovulation and timed artificial insemination in suckled Bos indicus beef cows?

The objective of the present study was to evaluate the effect of estradiol valerate administered at the beginning of the ovulation synchronization protocol on the pregnancy rate of Bos indicus cows. In the experiments, the following products from MSD, Sao Paulo, Brazil were used: estradiol valerate (EV), estradiol benzoate (EB), intravaginal progesterone device (P4), estradiol cypionate (EC), equine chorionic gonadotropin (eCG) and cloprostenol (PGF). In Experiment 1, Bos indicus cows (n=899) with a body condition score (BCS) of 2.

Use of injectable progesterone to replace the intravaginal progesterone device on the ovulation synchronization protocol reduces the pregnancy rate in Bos indicus cows.

The aim of this study was to evaluate the effectiveness of using different doses of injectable progesterone (P4i) in a new ovulation synchronization protocol in place of progesterone (P4)-releasing intravaginal devices in Bos indicus cows. For this, three experiments were carried out. To determine the P4-release curve (Experiment 1), 55 Bos indicus cows were distributed into 5 experimental groups for the administration of different doses of P4i at D0 (P4i60, n = 11; P4i105, n = 11; P4i150, n = 11; P4i195, n = 11 and P4i240, n = 11) and submitted to the ovulation synchronization protocol (D0: P4i + EB; D8: PGF2α + EC + eCG).