The objective of this experiment was to examine the effects of varying the interval from follicular wave emergence to progestin (controlled internal drug-releasing insert, CIDR) withdrawal on follicular dynamics and the synchrony of estrus. A secondary objective was to assess the effects of causing the dominant follicle (DF) to develop in the presence or absence of a corpus luteum (CL) on folli...

Two experiments were conducted to compare pregnancy rates resulting from fixed-time AI (FTAI) after administration of 1 of 2 long-term controlled internal drug release (CIDR)-based protocols. Heifers were assigned to treatment by age, BW, and pubertal status. The CIDR Select-treated heifers (Exp. 1, n = 37; Exp. 2, n = 192) received a CIDR (1.38 g of progesterone) from d 0 to 14, followed by 10...

Published data on the effects of ruminal bolus on the number of ovulatory follicles in ewes does not exist. The present study determined the effects of a ruminal bolus on trace element status, follicular dynamics and reproductive performance in ewes. Eighty Afshari cycling ewes were synchronized during breeding season using CIDR for 14 days and assigned to 4 groups (n=20); group 1 received a si...

The objectives of this study were to evaluate estrus response and pregnancy rates resulting from timed artificial insemination (AI) following estrus synchronization using CIDR in postpartum beef cattle. A total of 100 cows were randomly divided into three groups. Groups 1, 2 and 3 were artificially inseminated at 48-50 h (n=30), 53-55 h (n=30) and 58-60 h (n=40) after CIDR removal, respectively...

OBJECTIVE The aim of this study was to monitor the ovarian response and conception rate following estrous synchronization using CIDR, Ovsynch and double prostaglandin F2α protocols in Egyptian buffalo heifers. MATERIAL AND METHODS A total of 80 cyclic buffalo heifers were divided into four equal groups: CIDR (intravaginal progesterone releasing device, EAZI-BREEDTM CIDR®), Ovsynch (GnRH, PGF2...

Concentrations of progesterone have been reported to influence GnRH-induced LH surges. At the beginning of many synchronization protocols, GnRH is used to synchronize follicular growth. Therefore, the objective of this study was to determine the effect of elevated concentrations of progesterone from a controlled internal drug-releasing device (CIDR) on the GnRH-induced LH surge and ovulatory re...

In Exp. 1, we evaluated the effects of 2 lengths of progesterone exposure [CIDR (controlled intravaginal drug release); 7 vs. 14 d] before a modified CO-Synch protocol [50.0-microg injection of GnRH 6.5 d before a 25.0-mg injection of PGF(2alpha) followed by another injection of GnRH and fixed-time AI (TAI) 2 d after PGF(2alpha)], with or without temporary weaning (TW) before GnRH treatments, o...

The objectives of this study were to evaluate the effects of flunixin meglumine (FM), an inhibitor of PGF2α synthesis, administered at the time of embryo transfer (ET) and insertion of an intravaginal progesteronereleasing device (CIDR) at the time of ET on pregnancy rates (PR) and the resynchronization of estrus. Beef cows (n = 552) and heifers (n = 160) in three locations were assigned random...

Eighteen one-humped she-camels were divided randomly into three equal groups: group 1 served as control; group 2 (MGA) received (0.5 mg/ head/day) of Melengestrol acetate for 10 days and; group 3 (CIDR) were fitted intravaginally with controlled internal drug release (CIDR, 1.38g P4) for 10 days. At day 10 the MGA and CIDR groups were administered PGF2α and 3000 IU PMSG, MGA feeding was withdra...

OBJECTIVE The objective of this study was to compare reproductive performance parameters for two protocols for estrus synchronization in dairy heifers in Germany. MATERIAL AND METHODS In the CIDR group (n=93) all heifers received a controlled intravaginal progesterone releasing insert (Eazi-Breed™ CIDR®; Pfizer Pharma GmbH; containing 1,38g of progesterone) on day 0. On day 7 these cows were ...