AI Percentage question

[phillse]

Just got the pregancy blood test back. I am a little concerned. I usually average about 75% on the cows and 80 percent on the virgin heifers timed AI in our herd. I did some AI for another guy and do not know the results from those. However, just looking at our herd, things look crazy. They were set up as always, handling procedures the same and breeding the same. There were no big concerns at time of breeding. The results show I settled 87% of the grown cows and only about 25% of the heifers, results on the heifer are not on par and must be improved. I am trying to think of anything that might have made this sudden drop happen. Anyone have an idea or what I can do next year to improve.

The protocol used was
7-day CO-Synch + CIDR®-Cows
Perform TAI at 60 -66 hr after PG with GnRH at TAI.

CO-Synch + CIDR®-Heifers
Perform TAI at 54 ±2 hr after PG with GnRH at TAI.

Everything was heat detected and AI on am -pm rule if in heat if not observed in heat they were bred at TAI interval.

Looking back over everything, I can only come up with a couple of answers.

1. Semen quality on the bull for the heifers.
2. Give a shot of PG to the heifers a week prior to setup protocol

 

[lynnmcmahan]

I would run that by the experts at Auburn Univ

 

[cow pollinater]

Did you use sorted semen on the heifers? If so, then there's your answer.
If not, do you have another straw of the heifer bull? You might get your vet lab to take a look at it and make sure it's viable.
As for that lut shot, heifers are hard to synchronize. The standard protocols will work on them but you can't really second guess on them and change the program(unless you shorten it) like you can on a cow because the period of time where they have a cl can be pretty variable. That lute shot a week prior likely put about half of them in the worst part of the cycle to start a sync program on a heifer. If you had done the lute at three days prior to the gnrh you'd have been okay as they'd be ovulating on their own about the time you gave the gnrg but a week is to long on heifers.

 

[phillse]

Cow pollinated
I did not give a lute shot a week prior this year. You are right on the three days prior or as suggested by a semen rep give 2 to 3 weeks prior to protocol. Just as you suggested he suggested get the semen checked. However, he said a lot of people's conception rates were off this year. He is not who I normally get semen from but was contacting him about semen I recently purchased via auction from the junior livestock association in my county.

 

[cow pollinater]

2. Give a shot of PG to the heifers a week prior to setup protocol

That's from your first post. Now you're saying you didn't do it this year. I don't mean to come of as rude or argumentative at all but did they or did they not get prostaglandin a week before you started them on the sync?
And as for your semen rep, a lot of peoples' conception may have been off but yours on the cow side was fantastic. If we can assume that you haven't changed anything with the heifer management this year then the heifer breedings should have been better than they were.
How many head are we talking about here? If it's a small number then it could very well be an unlucky fluke but if we're talking a consistant pattern over a big group then you've got a real problem.

 

[phillse]

I can see that I did not word the original post very well. They did not receive lute prior to protocol this year. I was speculating that perhaps buy giving a shot prior next year that might improve conception rates. However, I did not make that clear in the 1st post. Yes it was a small group of heifers 8.

However, I may have discovered another possible reason after looking back at more of my notes. A front came in the morning I AI'd the heifers I had to bred them during a break in the rain. If that sounds plausible as a condition.

 

[cow pollinater]

A front the day of insemination shouldn't make any difference. A big front or any extra stress on the day you gave the lute shot would make a difference as adrenalin will block a response to lute.