Serum Concentrations of AMH and E2 and Ovarian and Uterine Traits in Gilts.

Poor sow retention due to reproductive failure is a common reproductive inefficiency amongst piggeries. This shows that traditional methods of gilt selection are inadequate and a marker of reproductive success is needed. The aim of this study was to determine whether circulating levels of AMH and E2 at D80 and D160 are associated with uterine and ovarian traits at D160. Uterine weight, horn length and horn diameter were measured, and ovarian follicle counts were determined histologically. There was a negative relationship between both D80 and D160 AMH levels and D160 ovarian follicle populations. There was also a positive relationship between D80 E2 levels and uterine capacity in gilts that were pubertal at D160. The findings indicate that D80 and D160 AMH could be used to predict ovarian reserve and that D80 E2 levels may be indicative of uterine capacity in precocial gilts.

Anti-Müllerian hormone and Oestradiol as markers of future reproductive success in juvenile gilts.

There is a need for an early marker for reproductive success in gilts as the traditional process for selecting breeding females is inefficient. There is evidence that circulating anti-Müllerian hormone (AMH) is indicative of ovarian reserve, antral follicle populations, gonadotropin responsiveness and fertility in various species other than the pig. Additionally, oestradiol (E2) has been shown to mark antral follicle populations in cattle and pregnancy outcomes in women, after gonadotropin treatment. The aims of this study were to determine whether 1) serum levels of AMH or E2, prior to or after gonadotropin injection at 60, 80 or 100 days of age, and 2) hormonal changes in response to gonadotropin stimulation (i.e. declining, plateauing or increasing hormone levels), are associated with future reproductive success in juvenile gilts. Serum samples were obtained at 0, 2 and 4 days after injection and mating and litter data were collected until parity three. Results showed that, regardless of age group and parity, Day 0 E2 levels were positively associated with the probability of stillbirth (P = 0.035) and E2 levels on Day 0 (P = 0.032), Day 2 (P = 0.045) and Day 4 (P = 0.019) were negatively associated with the number of piglets born alive. Further, both a single measurement of serum AMH levels at Day 2 (P = 0.048) and the AMH response type were associated with gestation length (P = 0.012). These findings suggest that serum AMH and E2 levels can be used to inform the selection of gilts for the breeding herd.