Negative impact of high doses of follicle-stimulating hormone during superovulation on the ovulatory follicle function in small ovarian reserve dairy heifers†.

When women with small ovarian reserves are subjected to assisted reproductive technologies, high doses of gonadotropins are linked to high oocyte and embryo wastage and low live birth rates. We hypothesized that excessive follicle-stimulating hormone (FSH) doses during superovulation are detrimental to ovulatory follicle function in individuals with a small ovarian reserve. To test this hypothesis, heifers with small ovarian reserves were injected twice daily for 4 days, beginning on Day 1 of the estrous cycle with 35, 70, 140, or 210 IU doses of Folltropin-V (FSH).

Genomic heritability and genome-wide association analysis of anti-Müllerian hormone in Holstein dairy heifers.

Anti-Müllerian hormone (AMH) is an ovarian growth factor that plays an important role in regulation of ovarian follicle growth. The objectives of this study were to estimate the genomic heritability of AMH and identify genomic regions associated with AMH production in a genome-wide association (GWA) analysis. Concentrations of AMH were determined in 2,905 dairy Holstein heifers genotyped using the Zoetis medium density panel (Zoetis Inclusions, Kalamazoo, MI) with 54,519 single nucleotide polymorphism (SNP) markers remaining after standard genotype quality control edits.

Development of the "waveless" bovine model.

Development of a bovine model without ovarian follicular waves (waveless) and transient increases in gonadotropin secretion during estrous cycles may lead to new methods to more consistently regulate ovulatory follicle growth thereby improving efficiency of embryo transfer. We hypothesized that the GnRH antagonist acyline would inhibit gonadotropin secretion thereby blocking follicular waves, ovarian function and ovulation during estrous cycles of cattle. To test this hypothesis, beef heifers (n = 5 per group) were treated twice daily with vehicle (control) or 25 or 50 μg/kg acyline beginning 12 h after GnRH-induced ovulation and ending 21 days later.

A single ultrasound determination of ≥25 follicles ≥3 mm in diameter in dairy heifers is predictive of a reduced productive herd life.

Fertility and productive herd life (time in herd after birth of first calf) are inferior in dairy cows with relatively low compared with intermediate but not high numbers of follicles growing during ovarian follicular waves. The present study, therefore, tested the hypothesis that fertility and productive herd life are lower in dairy heifers with high follicle numbers compared with age-matched herdmates with fewer follicles. To test this hypothesis, 11 to 15 mo old Holstein heifers were subjected to a single ultrasound measurement of the number of follicles ≥3 mm in diameter.

Anti-Müllerian Hormone (AMH) and fertility management in agricultural species.

A reliable, easy to assess marker for fertility in agricultural species would be highly desirable and Anti-Müllerian Hormone (AMH) is a promising candidate. This review summarizes recent findings concerning AMH and its role in fertility management, mainly in cattle. It focuses on (1) alterations in circulating AMH concentrations from birth to puberty and during estrous cycles; (2) correlation of circulating AMH concentrations with ovarian follicle numbers and ovarian reserve; (3) factors that impact circulating AMH concentrations; (4) use of AMH as a predictor of fertility.