lutalyse in heifers

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Mar 16, 2009
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one week ago today gave 30 open heifers a shot of lutalyse and have yet to see one breed or even act like it. This is my first time using any type drug for synching, what did I do wrong?
i don't know if they were coming in or not I purchased them from another farm. i just gave them all a shot before turning out. they are 15 to 16 months old, what should I expect now?
At that age they should be. What breed are they? Sounds like you might need to talk to your vet.
Did you get the lutalyse from a vet? If not, was it stored correctly? Does it have a current expiration date?
Lutalyse, which is a prostaglandin, will only have an effect if there is a viable corpus luteum to degenarate. Effectively it means that a single shot of Lutalyse will only have an effect from day 5 or 6 till day 16 or 17. Before that there isn't a viable CL yet and after that the CL is already degenerating and the heifer will be in heat anyway.

After a single shot of lutalyse expect about 65% of the heifers to show signs of heat within the next 6 days after the shot. Another option is to give a second shot 11 days after the first and theoretically all the heifers will be in heat 2-5 days after the second shot.

Your options are limited if its been longer than 11 days since you gave the Lutalyse, then i suggest its better to let the bull have his run and pregcheck 6 weeks after you pull him out.
What KNERSIE said plus if they are already bred the success rate of aborting the existing pregnancy goes down the further into the pregnancy they are.
I agree with Knersie & Dun.
What condition are they in? No matter how old they are, if they haven't reached a good weight, they won't be cycling & the shot only works on cycling cattle. But, that is amazing that NONE responded at that age.
What do they weigh??

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