Effect of two routes of administration of human chorionic gonadotropin upon oestrus induction and reproductive outcomes in adult acyclic mix-breed goats

• Published in: Journal of Applied Animal Research 2018-01, Vol.46 (1), p.190-194
• Main Authors: Rodríguez-Martínez, R., Meza-Herrera, C. A., Tapia-Robles, K. I., Alvarado-Espino, A. S., Luna-Orozco, J. R., Leyva, C., Mellado, M., Véliz-Deras, F. G.
• Format: Article
• Language: English
• Subjects: anoestrus season; Goats; hCG treatment; oestrus and ovulation induction; pregnancy rates
• ISSN: 0971-2119; 0974-1844
• DOI: 10.1080/09712119.2017.1284075

The effectiveness of two routes of administration of human chorionic gonadotropin (hCG) upon oestrus induction in anoestrus mix-breed goats was evaluated. Goats [n = 27, 39.6 ± 2.18 kg live weight and body condition score of 1.71 ± 0.02 units (scale 1-5)] were primed with 20 mg P4-intravulvosubmucosal (IVSM) 24 h prior to hCG administration. Thereafter, goats were randomly allocated to three groups to receive 100 IU hCG (0.1 mL) intramuscular (IM, n = 9), or IVSM (n = 9), and saline (0.5 mL) IM injection (CONT, n = 9). Ovarian follicular or luteal tissue was monitored by transrectal ultrasonographic scanning 15 days pre- and 5 days post-treatment. Besides, goats were daily monitored (0800 and 1800 h)  × 15 days to detect oestrus signs with the use of aproned sexually active bucks, treated with testosterone; 12 h after the onset of oestrus, goats were mated. While the CONT-goats never depicted neither oestrus nor ovulation (P  .05). Oestrus response (83.5%), pregnancy (60.6%) and litter size (1.55 ± 0.2) did not differ (P > .05) between the IM and IVSM groups. A single application of 100 IU hCG, irrespective of administration route, induced sexual activity in acyclic goats, generating key out-of-season reproductive outcomes.