First off 2 .5 year olds are going to do the bulk of the breading simply because there are more of them. While a 4.5 year old is spending time with a specific doe, 2.5 year olds are running around humping anything in heat that will let them get their hooves around. This is one of the reasons when I hade a place I could manage, we used our first tag to kill any 2.5 year old that was lacking brows, spindly racks, and had little or no tines on the beams, would also kill the mother if we knew who she was, 2.5 year olds that had a well balanced rack got a pass and their mothers were off limits.