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Dr. Todd
Dr. Todd, Large Animal Vet
Category: Large Animal Veterinary
Satisfied Customers: 754
Experience:  35 years of experience
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Post insemination, cows are not showing heat at 21days, but

Customer Question

Post insemination, cows are not showing heat at 21days, but when subsequently scanned are not in calf. I got a vacectimised bull but he is not picking them up either. What can I do.? I am thinking of using a coil at ,say, day 15. Thanks Michael
Submitted: 6 years ago.
Category: Large Animal Veterinary
Expert:  Dr. Todd replied 6 years ago.

Hello, Michael:


What percentage of your cows are pregnant after insemination?


How many of your cows are not showing heat at 21 days?


What are you vaccinating your cows against?





Customer: replied 6 years ago.
About50per cent success.

Of the 50per cent not in calf about 75per cent are not cycling.

Very little vaccination. I have put my resources into diagnostics, and we are basically clear of the usual diseases. Ie bvd, lepto, niosporo, etc and biosecurity is good. The herd is small 12 cows.
Expert:  Dr. Todd replied 6 years ago.

Is scanning the same as ultrasound examination?


Sometimes vasectomized bulls lose interest. They get no reward for their effort, so to speak.


Have you tried a 21-day heat trial?


Have you considered sychronization by using prostaglandin?

Customer: replied 6 years ago.
Yes.pregnancy scanning is by ultra sound.

The bull is working on in heat cows.
I do not understand the 21 day heat trial.

Prostaglandin (and progesterone coil) are used. In fact Iam thinking of using the coil 15dayys post insemination for 5/6 days on the basic that if in calf no effect and if not in calf it might induce heat. what you think?
Expert:  Dr. Todd replied 6 years ago.

The 21-day trial is a simple aid to improve heat detection. Make a list of all cows expected to be in heat during the next 21 days. As they come in heat, remove them from the list. One third of the cows should come into heat each week. Any cows not seen in heat during the 21-day trial should be examined.


I have no clients that use the coil so my comments are theoretical. Other than GnRH, I don't use any hormones after insemination. Progesterone should be safe, but I still wouldn't use it. I just don't like to do anything which might affect the pregnancy.


If you are certain that the cows are not pregnant, prostaglandin might be your best bet.


I will be away from the computer for a while. Kindly respond and I will reply later today.

Customer: replied 6 years ago.
My point was that Ido not want to use prostaglandin because of it's aborticant effect. Ultra sound is not reliable until posh 30 days,especially on big Charolais cows. basically my problem is that if they are not in calf I want to get working on them as soon as possible . They are not coming in heat, prostaaglin is an scanning is talking too long. I am not sure if there is a faster solution.

Expert:  Dr. Todd replied 6 years ago.



You might want to give prostaglandin another thought.


Yes, it can cause abortion if given to a pregnant cow. I do not treat a cow with prostaglandin unless I have cofirmed her open by palpation at 35 days post insemination. If I am not absolutely sure that she is open, I will palpate her a week later. I have not caused any abortions with prostaglandin. If used properly (given to an open cow) it can be a fairly reliable tool to bring a cow into heat.


Another reason for the lack of heats in some (not all) of the cows may be cystic ovaries. Rectal palpation or ultrasound would confirm cystic ovaries.


In response to your question about progesterone inducing won't.



This has nothing to do with your cows, but I'm very fond of Smithwick's ale.



Customer: replied 6 years ago.
Hi, I am back. I am accepting your answer to release payment, but unreality prostaglandin is not an answer.

Expert:  Dr. Todd replied 6 years ago.

Have you considered running a bull with the cows?