Relationship between the concentration of anti-Müllerian hormone and antral follicle count in pasture-managed Holstein cows in the high tropics

Abstract

We evaluated the relationship between plasma levels of anti-Müllerian hormone (AMH) and the number of antral follicles at the restart of the follicular wave in crossbred Holstein cows reared under extensive grazing systems over 2500 m above sea level. The study included 140 cows from 15 farms that were in average at the 75.3 ± 2.10 d post partum. Animals were synchronized according to the following regime: day 0 = intravaginal progesterone releasing device (IPD) + estradiol benzoate (EB); day 7: withdrawal of IPD + prostaglandin; and day 8: EB, for restart of the follicular wave on day 11. On this day 11, antral follicle counts (AFCs) were made by transrectal ultrasound, and a plasma sample was taken for the determination of AMH. The mean AMH plasma level was 0.06 ± 0.03 ng/ml and the mean AFC was 17.26 ± 0.38 follicles. A strong positive linear correlation was found between these two variables (r = 0.783, r = 0.613, P < 0.0001). Cows were categorized according to AMH concentration as high (>0.09 ng/ml), intermediate (0.09–0.05 ng/ml) or low (<0.05 ng/ml). Cows with high AMH presented a higher AFC (25.0 ± 2.21 follicles) than those with low AMH (14.08 ± 2.68 follicles; P < 0.001. Our results suggest that the cut-off value of AMH = 0.09 ng/ml may be useful for selecting donors in multiple ovulation embryo transfer programs involving cows with these characteristics. Our data further suggest that AMH plasma concentration correlates with AFC and can be used as an endocrine biomarker of the number of antral follicles present at a given moment of the estrous cycle in crossbred Holstein cows raised at altitudes above 2500 m.

Accuracy of ultrasound and visual inspection in antral follicular count in crossbred Holstein cows raised under grazing systems at high altitude

“…The AFCs obtained align with previous findings in cows under similar grazing management (Ayala Guanga et al, 2022). However, Holstein cows in tropics, fed total mixed rations exhibited between 11% (Gobikrushanth et al, 2017) and 25% (Furukawa et al, 2020) more antral follicles.…”

Lifetime milk production of Holstein cattle in the humid tropics compared to Holstein‐Gyr and Holstein‐Brahman crosses

“…For days open, it was found that GY × HO crosses reduced their ability to become pregnant when they were closer to pure breed Bos taurus . A possible explanation is the interaction between milk production and environmental adaptation (Guanga et al., 2022). A similar pattern is observed in BR × HO animals, whereas in the purebred Brahman, longer DO was also seen.…”

Efecto de la hormona Folículo-estimulante administrada vía epidural, sobre la respuesta ovárica y el perfil hormonal en vacas Holstein

“…El número de FA menores a 4 mm valorado el d del inicio de la onda folicular (d 4) fue similar (P>0,05) en T1 (19,3 ± 0,75) y T2 (19,9 ± 0,62; FIG. 3A), lo cual permitió iniciar el estudio en condiciones similares en cuanto al RFA en los dos T. Los resultados del RFA observados fueron similares al reportado previamente en vacas Holstein mestizas alimentadas al pastoreo en el trópico alto ecuatoriano (17,26 ± 0,38 folículos [15], o el descrito para esta raza (18,5 ± 9,0 folículos) en zonas altas de países de cuatro estaciones [16].…”