Progesterone supplementation improves fertility of lactating Holstein cows without a corpus luteum at initiation of the timed AI protocol

Abstract

Ovulation synchronization and timed AI programs have been adopted in many dairy herds for managing reproduction in cows. Timed AI programs ensure maximum submission rates. However, pregnancy per AI is reduced when cows do not have a functional CL at initiation of the timed AI protocol. Suboptimal progesterone concentrations as observed in cows without a CL at initiation of timed AI negatively affects the quality of ovulatory follicle, oocyte competence, embryo growth, and endometrial functions. Ultrasound evaluation of the ovaries at initiation of the timed AI protocol combined with targeted progesterone supplementation can improve fertility in dairy cows lacking CL initiation of the timed AI protocol. Intravaginal controlled internal drug release (CIDR) devices offer a practical method to increase plasma progesterone concentrations in cows without a CL at initiation of the timed AI protocol. Our objectives were to evaluate the effects of progesterone supplementation using 1 or 2 intravaginal progesterone inserts on fertility of first service lactating dairy cows without a CL at initiation of the timed AI protocol.