Aké-López JR, Heredia y AM, Alfaro-Gamboa M, Centurión-Castro F, Rojas RO

Language: English/Spanish
References: 0
Page: 225-233
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ABSTRACT

The aim of this study was to evaluate the effect of two hormones in the superovulatory response, and on the degree of synchronization of estrus between donor and recipient, on the pregnancy rate. Twenty-four Pelibuey ewes were superovulated with 500 IU of follicle stimulating hormone and luteinizing hormone (n = 14; FSH + LH group) or with 25 mg of follicle stimulating hormone (n = 10; FSH group). According to the degree of synchronization of the estrus, two groups of recipients were formed: ewes with 0 ± 12 h of asynchrony (n = 24) and ewes with more than 12 hours (› 12 h) of asynchrony (n = 15). Twelve ewes (85.7%) treated with FSH + LH responded satisfactorily to a superovulation with a mean of 12.41 ± 8.10 of corpora lutea (CL), 6.25 ± 5.69 total ova + embryos (TO + E) and 4.00 ± 4.86 transferable embryos (TE). Seven donors (70%) treated with FSH responded satisfactorily to superovulation with a mean of 8.28 ± 7.78 CL, 7.57 ± 5.86 TO + E, and 6.28 ± 4.79 TE (P › 0.05). The pregnancy rate was 58.3% for the recipients with 0 ± 12 h of asynchrony and 20% (P › 0.05) for the recipients that presented a › 12 h estrus. Results did not reveal significant effects of the hormone on the superovulatory response. The pregnancy rate increased when embryos were transferred in recipients with 0 ± 12 h of asynchrony.