
TY  - JOUR
A1  - Urakawa, M. 
A1  - Ideta, A. 
A1  - Hayama, K. 
A1  - Tsuchiya, K. 
A1  - Aoyagi, Y. 
T1  - 150 EXAMINATION OF ESTRUS SYNCHRONIZATION USING A PRID<sup>®</sup> + PROSTAGLANDIN F<sub>2&#945;</sub> AND PREGNANCY RATE AFTER ARTIFICIAL INSEMINATION FOLLOWING TRANSFER OF <i>IN VITRO</i>-PRODUCED EMBRYOS IN REPEAT-BREEDING COWS
JF  - Reproduction, Fertility and Development
JO  - Reprod. Fertil. Dev.
Y1  - 2007
VL  - 20
IS  - 1
SP  - 155
EP  - 155
KW  - 
UR  - https://doi.org/10.1071/RDV20N1AB150 
N2  - Repeat-breeding Holstein cows (RBCs), i.e. cows that have undergone three or more AIs, have reduced pregnancy rates. The present study aimed to determine whether application of a combination of a PRID® (ASKA Pharmaceutical Co., Inc., Tokyo, Japan) + prostaglandin F2&#945; (PGF2&#945;) for estrus synchronization and AI + embryo transfer (ET) would improve pregnancy rates in RBCs. All RBCs selected showed a normal interval between the previous insemination and estrus, and were free of clinical disorders. The RBCs (n = 107) received a PRID for 9 days with a capsule containing 10 mg of estradiol benzoate, 0.5 mg IM of cloprostenol (PGF2&#945;, Resipron®-C; ASKA, Japan) at 2 days before PRID removal. The cows were inseminated with frozen&#8211;thawed semen from a bull at 0 to 12 h after onset of estrus. Seven days after AI, single in vitro-produced embryos were transferred to the same RBCs. Pregnancy was diagnosed by palpation per rectum at e60 days post-insemination. Exp. 1 estimated the response to estrus synchronization treatment (n = 107). The factors examined were lactation number (mean ± SD: 2.3 ± 1.5, range: 1&#8211;6), insemination number (5.2 ± 2.2, range: 3&#8211;13), and the interval from calving to next AI (275.9 ± 97.6 days, range: 93&#8211;650 days). Exp. 2 compared the pregnancy rate in control RBCs (n = 161) and PRID-treated RBCs (n = 100). The factors examined included lactation number (2.5 ± 1.6, range: 1&#8211;12), insemination number (6.0 ± 2.5, range: 3&#8211;19), the interval from calving to next AI (288.0 ± 102.1 days, range: 102&#8211;797 days), and whether the ET was into the uterine horn ipsilateral or contralateral to the CL in a total of 261 RBCs. Data were analyzed using logistic regression. The results for Exp. 1: 103 cows (96.3%) were confirmed to be in estrus (2.0 ± 0.3 days after PRID removal). Although the frequency of estrus was affected by the lactation number (P = 0.014) and the interval from calving to the first AI (P = 0.005), the AI number did not have an affect (P = 0.624). Exp. 2: PRID synchronization had no effect on pregnancy rate (control: 37.3%, 60/161; and PRID-treated: 40.0%, 40/100). For the RBCs, the pregnancy rate was not affected by lactation number (P = 0.093), AI number (P = 0.694), or the interval from calving to next AI (P = 0.762). No significant difference (P = 0.428) in pregnancy rate was observed in cows when the embryos were transferred into the uterine horn contralateral to the CL (43.5%, 20/46), compared to those embryos transferred into the uterus horn ipsilateral to the CL (37.2%, 80/215). In conclusion, our findings suggest that the pregnancy rate may be improved by considering lactation number and the interval from calving to the next AI of RBCs in estrus synchronization using a combination of PRID + PGF2&#945; and AI + ET. 
ER  -

