Effects of estradiol cypionate (ECP) on ovarian follicular dynamics, synchrony of ovulation, and fertility in CIDR-based, fixed-time AI programs in beef heifers.

Estradiol cypionate (ECP) was used in beef heifers receiving a controlled internal drug release (CIDR; insertion = Day 0) device for fixed-time AI (FTAI) in four experiments. In Experiment 1, heifers (n = 24) received 1mg ECP or 1mg ECP plus 50mg commercial progesterone (CP) preparation i.m.

Effects of dose and route of administration of cloprostenol on luteolysis, estrus and ovulation in beef heifers.

Four experiments were conducted (with crossbred beef heifers) to determine the effects of dose and route of administration of cloprostenol on luteolysis, estrus and ovulation. In Experiment 1, 19 heifers with a CL > or = 17 mm in diameter were randomly allocated to receive cloprostenol as follows: 100 microg s.c.