Foal sex in Thoroughbred horses: related factors.

Reproductive biotechniques in the equine species have advanced in the last decade and horse breeders have started to question the possibilities of interfering in the determination of foal sex. The aim of the present study was to verify whether the variables mares and stallion's age, side of the ovary containing the preovulatory follicle, preovulatory follicle diameter, time between breeding and ovulation, and ovulation inducing hormones influence the sex of the foal. A total of 259 reproductive cycles of 160 mares and 22 Thoroughbred stallions were used.

and expression in spermatozoa is associated with stallion fertility and seminal quality?

This study aims to investigate the gene expression of sperm-borne (), WW domain-binding protein 2N-Terminal Like (), and Tumor necrosis factor (), as a negative control, in spermatozoa and their relationship with fertility and seminal quality in stallions. Ejaculates from 40 Criollo stallions were used, whose fertility was assessed on the basis of their pregnancy rate per cycle in at least two breeding seasons. Pregnancy rates ranged from 20% to 90% and were used to divide the stallions into two groups: High rates (≥ 50%) (n = 25), and Low rates (< 50%) (n = 15).

Hormonal Stimulation in a Gonadal Dysgenesis Mare.

The present case report aimed to determine the responsiveness of the endometrium and the ovaries of an X0 mare after hormonal treatment. On transrectal palpation, the uterus was flaccid and smaller than normal, and the ovaries were small and smooth. The endometrium had normal histological architecture, with an atrophic glandular epithelium.