If you have twin calves born at basically same time and one is a heifer and the other a bull is the heifer likely to be able to bred
Douglas County Kansas beef cattle
This condition in twin beef or dairy calves is fairly common. The heifer born twin to a bull is often infertile and is called a freemartin. This is caused by a shared blood supply and exposure to hormones produced by the male calf. Not all heifers born to a twin a freemartins but a high percentage are.