What got me wondering about the sex link and all that was because many years ago we raised Angus Holstein and Polled Hereford Holsten cross heifers. The Angus was from an old line bred herd and Holsteins were pretty closely bred also. The Polled Hereford bulls were whatever decent bull that could be gotten at the time. Pete had never seen a scur on any of his cows but it may have been that they were burned off when they were dehorned as babys. Nearly every one of the Angus sired heifer calves had scurs, none of the Hereford sired heifers calves did. Maybe there is besides a sex link a breed gene combination. Over the years all of the Angus bulls came from the same herd.