CIDR select protocol

[novaman]

Has anybody ever given prostaglandin on day 6 on the CIDR Select protocol. It seems all the protocols I see from the AI studs and the like recommend the prostaglandin on day 7. I am wondering whether this is a convenience deal as day 7 is also the removal of the CIDR. I was reading the package of the CIDR's and it says to give the prostaglandin on day 6. I was just curious if anybody has done both ways and if one way is better than the other. I am working with dairy cows so there is no problem going on day 6 if it works better.

 

[angus9259]

I've done both and couldn't testify to any difference. I do day 7 for convenience. If I were in a dairy, I'd do day 6 per the CIDR instructions.

 

[novaman]

I've always done day 7 but I thought I would give day 6 a try. The only thing I'm questioning is if I give it on day 6 they typically come into heat 3 days later and that would put me at day 9 rather than the TAI that I would be doing on day 10. Does it work out to still be day 10 for TAI even with giving the prostaglandin on day 6?

 

[bigag03]

If you are using TAI, I strongly recommend day 6 prostaglandin. This will tighten the window of heats. If you are observing heats then use day 7 prostaglanding for convenience.

By giving prostaglandin on day 6, you regress any CL's present so that when you pull the CIDR on day 7, all cows are "ready" to come into heat. By using the day 7 shot, some cows without a CL will be ready to respond immediately while the cows with a CL present will be delayed since the CL has to regress to stop progesterone production.

 

[vclavin]

If you are using TAI, I strongly recommend day 6 prostaglandin. This will tighten the window of heats. If you are observing heats then use day 7 prostaglanding for convenience.

By giving prostaglandin on day 6, you regress any CL's present so that when you pull the CIDR on day 7, all cows are "ready" to come into heat. By using the day 7 shot, some cows without a CL will be ready to respond immediately while the cows with a CL present will be delayed since the CL has to regress to stop progesterone production.

Would the day 6 shot then make the TAI more successful... higher % bred?
Valerie

 

[bigag03]

Sorry for the delay; I have been away for a while.

Yes, I do believe you will have a higher conception rate with prostaglandin on day 6. If you give prostaglandin at the same time you pull the CIDR, you will have two distinct populations of cows. 1) Those cows that are "ready" to come in heat because they do not have a Corpus Luteum (CL) present are just waiting for you to remove the CIDR and 2) Those cows that have a CL that will have to regress in addition to pulling the CIDR. By giving prostaglandin on day 6, you can increase the likelihood that CL's are regressed so that these cows come in heat just as fast as those that had no CL.

 

[KNERSIE]

I've only ever given it on day 6, but my success rate with CIDRs never got any higher than about 70% and even then you still need to watch for a few stragglers that will come in heat a day after the rest. If you know your cows are cycling I wouldn't ever use another method except the two shots of Estrumate 11 days apart and heat detect for 5 days after the second shot. With this method I regularly get 90% on a single service and have gotten 100% in the past on smaller groups.

 

[bigag03]

I've only ever given it on day 6, but my success rate with CIDRs never got any higher than about 70% and even then you still need to watch for a few stragglers that will come in heat a day after the rest. If you know your cows are cycling I wouldn't ever use another method except the two shots of Estrumate 11 days apart and heat detect for 5 days after the second shot. With this method I regularly get 90% on a single service and have gotten 100% in the past on smaller groups.

I agree 100% if you have the ability to breed on heat, but there are many breeders that do not have that option. With TAI, CIDRs are still the best method.