I've heard of line breeding but isn't brother on sister a bit to close? I thought u needed 2 separate genes to avoid deformities, with brother on sister there would be a full gene missing and I've seen the offspring from this in the past with over and under shot jaws. Isn't line breeding to be done from the uncle or aunt??? Or have I totally misread your post? Or not have it right myself. Atb. Lance.
no never brother an sister breeding way to close!