Guys, I know that this is an old topic and has been over for a while now, but I just wanted to pass on something for you all to ponder. Statistically speaking older females of any species whether it be deer, elk, chimpanzees or humans are more prone to birth defects, premature birth, and increased infant mortality. This is because when reaching sexual maturity all female mammals have developed all the eggs they're ever going to. As time goes on and the body ages, these eggs become more and more prone to DNA mutations due to a variety of external and internal factors. Its a proven fact that the older a female is the more likely for an adverse outcome. If your looking to improve the "gene pool" in your area, allow bucks to breed does whose genetic zygote is in its prime. TAKE OLD DOES..... Period. This will not only help to rid the population of unwanted genetic trends, but create a more hearty heard. BTW, older does mean just that, does still capable of breeding but out of their prime breeding years.