196 Embryo production using follicle-stimulating hormone (FSH) or FSH + equine chorionic gonadotropin in beef donors
J. L. Barajas B C , A. Cedeño B C E , S. Andrada B D , J. A. Ortega B C , J. M. Oviedo B , A. Tribulo B D , R. Tribulo B D , H. Tribulo B C and G. A. Bó A BA Instituto A.P. de Ciencias Básicas y Aplicadas, Universidad Nacional de Villa María, Villa del Rosario, Córdoba, Argentina;
B Instituto de Reproducción Animal Córdoba (IRAC), Paraje Pozo del Tigre, Córdoba, Argentina;
C Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Argentina;
D Facultad de Ciencias Veterinarias, Universidad Nacional de La Rioja, Argentina;
E Escuela Superior Politécnica Agropecuaria de Manabí (ESPAM MFL), Medicina Veterinaria, Bolívar, Manabí, Ecuador
Reproduction, Fertility and Development 31(1) 223-223 https://doi.org/10.1071/RDv31n1Ab196
Published online: 3 December 2018
Abstract
The objective of the present study was to evaluate the superovulatory response and embryo production in beef donors using 8 twice-daily injections of FSH or an alternative protocol in which the last 4 FSH injections were replaced with a single injection of eCG. In Exp. 1, 12 mature Bonsmara donor cows, with a body condition score between 3 and 4 (1 to 5 scale) were superstimulated twice every 46 days in a crossover design (i.e. in each experiment all cows received 2 treatments and the 2 treatments were equally represented in each replicate). On Day 0 a.m., all donors received an intravaginal device with 1.2 g of progesterone (Diprogest 1200®, Zoovet, Santa Fe, Argentina), along with 50 mg of progesterone i.m (Progestar®, Zoetis, Buenos Aires, Argentina) and 5 mg of oestradiol-17β (17βOestradiol®, Rio de Janeiro, Argentina) IM. On Day 4 a.m., the superstimulatory treatments were initiated and donors in the control group received 8 applications of FSH (Folltropin-V, Vetoquinol, Lure, France), IM (total dose: 300 mg NIH-FSH-P1) in a twice-daily decreasing dosage schedule over 4 days (i.e. 60, 60, 50, 50, 30, 30, 10, and 10 mg, respectively). Donors in the FSH + 800 eCG group received only the first 4 applications of FSH (i.e. 60, 60, 50 and 50 mg, respectively) and on Day 6 a.m. they received 800 IU of eCG (Novormón®, Zoetis) IM in a single dose. All donors received 500 μg of cloprostenol (Ciclase DL®, Zoetis) IM on Day 6 a.m. and p.m., and the intravaginal devices were removed on Day 7 a.m. All cows also received 100 μg of gonadorelin acetate (GnRH, Gonasyn gdr, Zoetis) on Day 8 a.m. and were inseminated with frozen-thawed semen from 2 bulls 12 and 24 h later. On Day 15, ova/embryos were collected and evaluated according to the IETS standards. The data were analysed by GLMM (Infostat, 2018). In Exp 2., 18 Bonsmara donors with similar conditions as those in Exp. 1 were superovulated twice in a crossover design. Cows in both groups received similar treatments to those in the FSH + eCG treatment of Exp. 1, except that the total dosage of FSH was 200 mg (i.e. 60, 60, 40, and 40 mg, respectively) and the eCG given on Day 6 a.m. was either 600 IU (group 1) or 800 IU (group 2). In Exp 1., the FSH (control) group had a higher (P < 0.01) number of fertilized oocytes, but there were no differences in the other end points evaluated (Table 1). In Exp. 2, no differences were found between FSH + 800 eCG and FSH + 600 eCG groups in any of the parameters evaluated. In conclusion, the replacement of the last 4 injections of FSH by a single dose of eCG decreases the number of treatments required in a superovulation program without negatively affecting the production of transferable embryos.
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