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Effect of estrus synchronization treatment after luteolysis on Holstein heifers as embryo transfer recipients
Author(s) -
YOSHIDA Tatsuyuki,
SATO Taro,
CHIBA Koji,
YOSHIMURA Itaru,
OSADA Masahiro,
OKADA Konosuke,
FURUTA Hiroki,
OHTA Akihiko,
USHIJIMA Hitoshi
Publication year - 2012
Publication title -
animal science journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.606
H-Index - 38
eISSN - 1740-0929
pISSN - 1344-3941
DOI - 10.1111/j.1740-0929.2011.00994.x
Subject(s) - luteolysis , estrous cycle , embryo transfer , estrus synchronization , synchronization (alternating current) , andrology , embryo , biology , zoology , corpus luteum , pregnancy , artificial insemination , endocrinology , medicine , ovary , mathematics , microbiology and biotechnology , genetics , topology (electrical circuits) , combinatorics
This study was designed to evaluate the effect of estrus synchronization treatments on recipient heifers for embryo transfer (ET). Holstein heifers were separated into the following three groups: (i) an administration of 50 µg GnRH (gonadotropin‐releasing hormone) analog was given to heifers at a random stage of the estrus cycle, followed 7 days later by two administrations of 7.5 mg prostaglandin F2 alfa analog (PG) as control; (ii) another administration of 100 µg GnRH was given to the control group at 48 h after the administration of PG as the second GnRH group; and (iii) an administration of 0.75 mg estradiol benzoate (E2) was given to the control group at 24 h after the administration of PG as the E2 group. Each method caused estrus synchronization. Fresh embryos were nonsurgically transferred into the suitable recipients that had a functional corpora lutea (CL) 7 days after estrus. The E2 group showed a significantly higher ( P < 0.01) rate of estrus synchronization (98.9%) at 1–3 days after PG administration and the final pregnancy rate of the E2 group (50.6%) was also significantly higher than the other groups (37.1%, P < 0.05 and 30.9%, P < 0.01, respectively). These findings demonstrate that E2 administration 24 h after PG protocol is effective for estrus synchronization of Holstein heifers, thus improving the productivity of ET.