Twin heifer calves that have a male twin are virtually always infertile and called Freemartins.

The male twin may have died during pregnancy or be still born, therefore it may not be obvious that a heifer is a twin.

At GeneMark we can identify Freemartins and save you the time and expense of rearing infertile heifers.

*A Freemartin test requires a blood sample (purple stopper)