Over the years, I heard hunters say that bigger deer (whether that refers to body or antler size) will pass their genes on to their offspring. This, of course, is true, but what some of them also believe is that these genes for bigness don't get passed on until the deer who's doing the breeding has grown to be big himself. That isn't true. All animals (and humans, for that matter) carry all the genes - and gene quality - that they will pass on from the day they are born. These may include, size, color, etc. So, when the buck (or doe) that is carrying those desirable genes starts breeding, he (or she) will be passing on those genes from the very first time he (or she) breeds. The genes just don't get better as the deer gets older or bigger.