Steve, I have some heifers right now that are still holding onto their winter coat. It won't surprise me to find they didn't breed. The rough hair coat is an indicator of over-all health. They have something going on that has them out-of-balance. If they aren't in balance with nature, they may not cycle.
BUT-there are so many factors like hot weather and vaccinations and mineral and 'you name it' that a rough hair coat is simply part of the total assessment. Last year, my heifers slicked off perfectly but the County cut the trees along side their pasture to make the road more accessible for large farm equipment, Those heifers lost all their shade in that pasture. I had 50% opens. I kept the opens and they all rebred for my fall herd. I won't give Long Range injectable to yearling heifers because it seemed to affect preg rates. That may not be the case for anyone else.
Hair coat is just part of the total equation.