Tried something new and it has worked for us

[hornedfrogbbq]

We were seeing some of our cattle coming into heat early or just a bit late versus our AI session. In this case, we are talking about cows on a 7 day co-synch with a CIDR. Soooo, we decided to put our cover bulls in after the last Lute shot, about 60 hours before we'd AI. Our cover bulls are probably too expensive and too good to be used as such (which is why i posted the previous question on potentially buying cheaper, different breed cover bulls) but that also means i'm indifferent as to getting an AI calf or a cover bull calf. We take the bulls off of them 12 hours or more before the AI session and then put them directly back on them post the AI session.

The reasoning is we'd prefer to catch those that don't AI breed or wouldn't AI breed and get that calf 21 days earlier. That does make it difficult to impossible to know what the parentage is but we can run tests for that. Our conception rate jumped up about 5-7%. We are a commercial herd and all of our bull calves are castrated and terminal so I'm not providing seed stock and don't need a certain sire group to sell bulls from.

Just an fyi...it has worked for us for two years in a row. I was wondering if other folks do this and if not, why not?

 

[Jeanne - Simme Valley]

I just put together an article on using one shot syncronization for all natural breeding, but you could modify & AI during the day 6 to 10:

"This protocol calls for bulls to be turned out with the cows on Day 0. On Day 5, cows are given a shot of prostaglandin (PGF2α) which synchronizes a majority of the cows to be in heat/estrus from Day 6 through Day 10. The injection of prostaglandin causes any cows with a corpus luteum present on one of their ovaries to regress, ceasing progesterone production. This then triggers the cows to come into heat/estrus.

If the cow conceives during Day 1 to 5, she will not abort when given the prostaglandin injection on Day 5 because the developing corpus luteum at the site of ovulation on the ovary has not yet reached maturity and will not respond to prostaglandin."

Remember, Prostaglandin (Like Lutalyse) ONLY works on cows that have started cycling.