Could be a deficiency off the top of my head - Zinc, Cobalt and Potassium can all affect hair. Do they have some sort of supplement that is good for your area? If you do then it could be as simple as a difference in weather. Or as dun says, some do and some don't. I have a fuzzy calf that stayed pretty fuzzy all summer. It's a good thing here to have a calf with a good hair coat. They sell better than those really slick calves that tend to get colder.