HTMA has been responsible for live on ground, safe delivery of many foals. Mares that have hormonal imbalances rarely produce live healthy foals or fail to conceive at all. It is common for such mares to have a dominance of testosterone in relation to estrogen & progesterone. These mares display "mareish" behaviour when cycling or have irregular cycling. Adequate levels of selenium combined with a correct ratio of zinc to copper balances hormone levels. It is advisable to know your mares hormone levels before embarking on a breeding program.