A)The traditional belief is that twisted or ?corkscrew? antlers are grown by bucks suffering from the liver fluke Fasciola hepatica, a leaf-shaped parasite that lives in the bile ducts of the liver. A number of animals carry them, including sheep, cattle, deer, rabbits and hares. Roe are more vulnerable to the effects of infestation than other deer species. A secondary host, the mud snail Limnea truncatula, is involved in the life cycle, so roe living in damp pastures, especially those used by cattle or sheep, are liable to pick up fl uke from the snails and suffer accordingly. Combined with harsh winter weather, they can be the cause of significant mortality in a roe population, let alone affecting their capacity to grow normal antlers the following spring.
Sadly, there is not much you can do, in practical terms, to surmount your trouble if, as I suspect, the cause is fluke. It would be worth investigating the livers of any shot deer to confirm this diagnosis. In the case of your environment, it is pointless trying to eliminate the corkscrew heads by selective shooting, though it is always a good policy to weed out poor specimens. You could perhaps look at the possibility of improving the feed higher up the hill so that the low ground is less attractive to the roe by planting, for example, willows as supplementary browse.