FoalSafe is a craftable item. Users in the Pharmaceutical Sciences stream can craft it using altrenogest

Course Article

Improving Implantation Rates

Embryo transfer can be a very frustrating process, as getting the embryo to implant in the recipient mare can be very difficult. Unfortunately, there isn't much to be done to help improve the likelihood of implantation occurring, but providing a mare with progesterone early in pregnancy can help her maintain that pregnancy when the embryo is in its most fragile state. Therefore, giving mares altrenogest, a synthetic progesterone, early in pregnancy may help improve conception rates from embryo transfer.

Altrenogest works to help maintain pregnancy by supplementing the mare's naturally circulating levels of progesterone. Progesterone is considered the "pregnancy hormone", and is produced by the corpus luteum (CL), which is the structure that remains after a follicle on the ovary ovulates. The high levels of progesterone from the CL causes the mare to stop having heat cycling, and prepares the reproductive tract for pregnancy and embryo implantation. If implantation does not occur, the uterus will release prostaglandins which destroy the CL, causing progesterone levels to drop, allowing the mare to return to heat cycling.

By giving synthetic progesterone in the form of altrenogest, the mare's progesterone level is artificially raised. This may help mares who may have a naturally low level of progesterone maintain their pregnancy, because fluctuations in the progesterone level produced by the CL do not drop low enough to allow the mare to return to cycling. However, in practice, altrenogest has very inconsistent results in helping mares keep a pregnancy.

If you wanted to try altrenogest, it is usually given on top of the mare's grain starting a few days after ovulation, and continuing for 120 days. After 120 days, the placenta should have developed sufficiently, and it takes over progesterone production from the CL.

In Oxer To Oxer, the altrenogest feed supplement is called Foal Safe. It can be given once per year, and should be given prior to using the mare as a recipient. Because it a drug product, it can only be produced by Pharmaceutical Scientists.

1. McCue, PM. Progesterone Primer. Colorado State University. http://csu-cvmbs.colostate.edu/Documents/Learnmares23-hormther-progesterone-apr09.pdf