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...

One hundred female Markhoz goats (42±5 kg) were used to investigate the ‘male effect’ on estrous synchronization and reproductive characteristics of female goat during the breeding season. This was carried out in three separate experiments. In the first experiment, forty female goats were used in 4 groups with different distance from the male goats (i.e. source of pheromone secretion); A1 (1 me...

Bos indicus x Bos taurus (n=251) and Angus (n=323) cows received a progesterone containing device called an Eazi-BreedTM CIDR® for 7 d with a prostaglandinF2a (PGF2a) injection at CIDR removal. At CIDR insertion half the cows received a GnRH injection and half did not. Upon CIDR removal, half the cows in both GnRH and No-GnRH groups were equally divided into two AI treatment groups: 1) injectio...

this experiment were carried out to compare different short-term oestrous synchronization methods in farahani ewes to determine of the best method, so were used 123 ewes from a herd in delijan city in markazi province. after ensuring their health, ewes were divided  to five experimental groups randomizely. the oestrous cycles of the ewes were synchronized using these five methods: 1) use of cid...

one hundred female markhoz goats (42±5 kg) were used to investigate the ‘male effect’ on estrous synchronization and reproductive characteristics of female goat during the breeding season. this was carried out in three separate experiments. in the first experiment, forty female goats were used in 4 groups with different distance from the male goats (i.e. source of pheromone secretion); a1 (1 me...

Several effective fixed-time AI (FTAI) protocols have been developed to facilitate AI in beef heifers that circumvent the need for estrus detection. Among these are the 5-d CO-Synch + controlled intravaginal progesterone insert (CIDR) protocol (5dCO), PGF2α (PG) 6-d CIDR protocol (PG-6dCIDR), and 14-d CIDR-PG protocol (14dCIDR-PG). Although each of these protocols varies in duration and approac...