AI timing

[ozbreed]

Any thoughts on the optimum time to AI after the first sign of detected standing heat. Does anyone think it needs to be a different interval for natural heats, PG induced heats or CIDR induced heats? 12 hrs still seems the best for us

 

[Hoop]

12-18 is what we have done. Most of what we have done in recent years is timed AI using gnrh at time of breeding.

 

[Haytrucker]

In my experience in the last several years 12 hours after standing will get an average conception rate of 65%. That is behind CIDR's and the regimin of hormones. The yearlings will be a little better, the older cows not quite, with some interesting variances. Both herds had a better rate during severe drought years, with the first-calvers scaring 85% in the first cycle, and nearly all of that in ten days. On tall green grass one set of nursing cows only made 45% to AI, but calved near 70% in 21 days.

 

[Hay Feeder]

Our University ultrasounded 100 heifers with 63 percent AI calves bred to the same bull.. 11 were open the balence were bull bred. Cleanup bulls were rotated.

50 cows 60 percent AI however 90 percent have bull embryos in them this was conventional semen from two different bulls. 8 cows bull bred and 12 open. One comming two year old bull was used for cleanup

Cows were timed on the 7 day CDIR and heifers were on the 14 day CDIR
I helped with every phase of the project and for a fact everything was done exactly to the time hour and minute. Except the AI crew showed up 30 minites late for the cow breeding.

These were from the same ranch all black commercial cattle bred to an AI company semen.

The ultrasound was done 88 days after AI