Association of recombinant bovine somatotropin (rBST) with equine chorionic gonadotropin (eCG) on antral follicle count and oocyte production in Holstein and Tabapuã heifers

Revista Brasileira de Zootecnia

Carvalho, Rafaela Rodrigues de¹  Gonçalves, Tarcísio de Moraes²  Souza, José Camisão de²  Morais, Hévea de¹  Pinto, Tássia Louregiani Carvalho¹  Spuri, Renata¹  Andrade, Renato Campos¹ 

[1] Universidade Federal de Lavras, Lavras;Universidade Federal de Lavras

关键词: embryo;    hormonal stimulation;    ovary    Introduction Oocyte yield obtained after bovine ovum pick up (OPU) and OPU-derived embryo yield after in vitro culture (IVP) are low;    especially in relation to the antral follicle population available at the time of ultrasound-guided follicle aspiration (Blondin et al;   

DOI  :  10.1590/S1516-35982012001200004

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

The objective of this study was to investigate whether the use of rbST and eCG prior to ultrasound-guided follicular aspiration (OPU) improves oocyte yield and quality in Tabapuã and Holstein heifers. The study was conducted in two phases, 20 days apart, in a change-over design. The dominant follicle was ablated two days (D-2) before two treatments: stimulation (6 Holstein and 8 Tabapuã), 500 mg of rbST (Boostin®) on D0 and 500 IU of eCG (Folligon) on D2; and control (6 Holstein and 8 Tabapuã), in which heifers received injections of the excipient. Heifers were aspirated on D4. Oocytes were subjected to a well established commercial in vitro embryo production protocol (Vitrogen®) and embryos were evaluated seven days after fertilization. There was an effect from the interaction of treatment and breed, so that hormonal stimulation increased antral follicle count (2-8 mm) in Tabapuã (29.9±2.6 to 41.4±2.6), but not in Holstein heifers (14.4±2.6 to 15.5±2.6). Tabapuã heifers had higher mean antral follicle count than Holsteins (35.6±1.8 vs. 15.0±2.1). The number of viable oocytes was not increased by stimulation in Tabapuã (from 4.7±1.0 to 5.2±1.1 in control and simulation, respectively) or in Holstein heifers (1.3±1.9 to 2.0±1.6 in control and simulation, respectively). There was no difference in the percentage of heifers with more than five viable oocytes in the group treated (33 vs 27%). The number of blastocysts was not affected by treatment (1.75 vs. 1.00 in hormonal stimulation and control, respectively). The increase in antral follicle count in the stimulated Tabapuã heifers did not reflect upon oocyte yield. The differential breed response to the hormonal treatment underscores the need for additional tests, especially for the Holstein breed, in order to enhance OPU efficiency.

【 授权许可】

CC BY-NC