| Autor: |
Facioli FL; Faculdade de Agronomia e Medicina Veterinária, Curso de Medicina Veterinária, Universidade de Passo Fundo, Passo Fundo, RS 99052-900, Brazil., De Marchi F; Faculdade de Agronomia e Medicina Veterinária, Curso de Medicina Veterinária, Universidade de Passo Fundo, Passo Fundo, RS 99052-900, Brazil.; Programa de Mestrado em BioExperimentação, Universidade de Passo Fundo, Passo Fundo, RS 99052-900, Brazil., Marques MG; Programa de Pós-Graduação em Produção e Sanidade Animal, Instituto Federal Catarinense, Concórdia, SC 89703-720, Brazil.; Laboratório de Sanidade Animal, Embrapa Suínos e Aves, Concórdia, SC 89715-899, Brazil., Michelon PRP; Médico Veterinário Autônomo, Passo Fundo, RS 99052-321, Brazil., Zanella EL; Faculdade de Agronomia e Medicina Veterinária, Curso de Medicina Veterinária, Universidade de Passo Fundo, Passo Fundo, RS 99052-900, Brazil.; Programa de Mestrado em BioExperimentação, Universidade de Passo Fundo, Passo Fundo, RS 99052-900, Brazil., Caires KC; Department of Human Nutrition, Food and Animal Sciences, University of Hawaii, Manoa, HI 96822, USA., Reeves JJ; Bar-R Cattle Company, Pullman, WA 99163, USA., Zanella R; Faculdade de Agronomia e Medicina Veterinária, Curso de Medicina Veterinária, Universidade de Passo Fundo, Passo Fundo, RS 99052-900, Brazil.; Programa de Mestrado em BioExperimentação, Universidade de Passo Fundo, Passo Fundo, RS 99052-900, Brazil. |
| Abstrakt: |
The Japanese black cattle breed (Wagyu) has an improved metabolism, which allows them to have a higher marbling score when compared with other cattle breeds. However, this may affect other aspects of the animal's physiology, including hormone secretion and their reproductive success, such as their response to synchronization protocols and embryo production. Therefore, the objectives of this study were to test a superovulation protocol (SOV) developed with low doses of FSH and to evaluate the outcome and economic viability of embryo production using the SOV and in vitro fertilization (IVF) approaches in the Wagyu cattle breed. For that, ten Wagyu cows were submitted to five SOVs over a period of 15 months using a standard protocol: CIDR + 3 mg estradiol benzoate (D0), 35 mg FSH (Folltropin ® ) a.m. and p.m. (D4), 35 mg Folltropin ® a.m. and 20 mg p.m. (D5), 20 mg Folltropin ® a.m. and 10 mg p.m. (D6), 10 mg Folltropin ® and 0.5 mg cloprostenol, both a.m. and p.m., + CIDR removal (D7), 0.05 mg GnRH + insemination 12 and 24 h after (D8) and embryo collection + 0.5 mg of cloprostenol (D16). Thirty days after each SOV, a follicular aspiration was conducted to produce IVF embryos without any pre-synchronization using standard semen in the same group of animals. The average number of embryos produced was 7.63 ± 5.61 (SOV) and 4.52 ± 2.44 (IVF) ( p = 0.303). There was no significant correlation between the number of embryos produced by the different techniques (SOV and IVF), indicating that cows that respond well to SOV did not respond well to IVF and vice versa (r = 0.379, p = 0.529). The total cost of each embryo produced by SOV was R$215.00 and R$410.00 for IVF. Therefore, cows that produce less than five embryos by SOV are not economically viable due their lack of response to FSH, and the use of IVF in those animals may be more effective. |
