Somatotropin vs. follicle-stimulating hormone: Antral follicle count in lactating and non-lactating cows

Payano I.U.; Eulogio C.Q.; Gomez E.A.; Villar F.A.; Fermín J.U.; Saavedra E.; Mauricio-Ramos Y.; Sarapura V.; Ninahuanca J. · Revista Veterinaria (2025) · DOI: 10.30972/vet.3618159

Resumen

The objective was to evaluate the effect of follicle stimulating hormone (FSH) and bovine somatotropin (bST) on follicular dynamics in lactating and non-lactating dairy cows. A 2×2 factorial ANOVA was performed, considering lactation status and the hormone used as factors. A total of 20 cows were administered, 10 lactating (5 treated with FSH and 5 with bST) and 10 non-lactating (5 treated with FSH and 5 with bST). In lactating cows, bST treatment resulted in a significantly higher total follicle count (16.4 ± 2.3) compared to FSH (11.8 ± 1.92), whereas no significant differences were observed in non-lactating cows (p>0.05). Regarding the number of follicles measuring 2-4 mm, significant differences (p<0.05) were found in lactating cows, with bST resulting in a higher count (12 ± 1.41) compared to FSH (6.4 ± 1.34). For follicles measuring 4-8 mm, no significant differences were observed between groups (p>0.05). In terms of viability, bST showed better results, with significant differences (p<0.05) compared to the FSH group in both lactating and non-lactating cows. These findings highlight the need to adjust hormonal protocols based on the cows’ physiological state to maximize viable oocyte production, which is crucial for assisted reproduction and improving reproductive efficiency in the livestock industry.

Instituciones: Universidad Peruana Los Andes; Universidad Nacional del Centro del Perú