We've recently been talking about this in my college animal science class and my professor says and I agree that fall if you can do seems to have more advantages. If you calf in the fall it's cooler so you can get better breed back, usually not as muddy so you don't have to deal with that, usually less scours as grass is not full of sugar instead of water, no more endophyte in fescue (i'm in ky so that's a major forage) and prices are usually at their highest in spring. If you are able to stockpile forages and strech your days grazing that can greatly reduce the amount of hay and byproducts you have to feed your lactating cows.
so i think you can tell I'm now a fan of fall calving.. :tiphat: