Bull gestation length?

[Amo]

I A.I. some cows. Just courious how long after "D-Day" do you still consider a calf AI sired?

What I do is 10 days on either side of the date of expected calving. Heiffer bulls (short gestation) come before that of course. So I use an Angus bull with a +4 BW epd. Which should mean a longer gestation length. So guess what Im wondering is does anybody know what corralation of days to EPD # .

After I breed them I put them out to pasture with the clean up bull. Yes I know there is a chance of them being bull bred right away. Do that so I can up my stocking rate for pasture rotation instead of waiting 15-20 days. I use KMARS and heat detect, so I think the chances are very slim of them comming into standing heat shortly after AIing. Also the clean up bulls are heavier birth weight bulls. So that should give me more leway on the back end of "D-Day". So if its a heavy bw AI sire I might streach the 10 day rule a tick. Usually it comes pretty close though.

Just wondering what other people do.

 

[dun]

For cows that we will AI and then run with a clean up bull we use a Hereford or homo black bull for AI. Our clean up bulls are Red Angus

 

[blacksnake]

Don't forget that the bull is not the only contributor to the gestation length. I have some cows that all always over no matter what I breed them to and some that are always short. I have gone as much as 20 days short and almost as much on the long side.