Do you guys see a difference in conception rates from implanting 3-6 year old cows as opposed to say 8-11 year old cows. We average over 80% conception on our younger cows. We had 7 older cows that were treated the same and got the same embryos as the youger group and every one didn't take. This is the first year we had used cows this old we had some extra eggs to put in and just used those cows. Any opinions or past experiences would be appreciated.