Hey Randy has been working on a research article for this very same topic. The plan is for it to come out in the next issue of Deer Tracking. Just a heads up, on the farm he has studied there is no indication that linebreeding is a factor or that it in any way is an indication of poor health or poor quality. The animals are of good genetics and thoroughly DNA'd and out of some of the top line genetics.
If you need any futher information before the article comes out, give Randy a call.