READER: Last year, I had a Red Angus heifer that couldn't get bred. I was told by a young vet that she probably had a cyst on her ovary, and that was why she kept coming back in heat. She was treated with a shot of Lutalyse and went on to conceive. She had a beautiful red calf. Will she breed back normally, or do I need to plan for her to have a Lutalyse injection prior to breeding season again?
DR. McMILLAN: First, let's talk about cystic ovaries. This is a condition that occurs when the normal estrus cycle is interrupted.
Normally, follicles develop on the ovary, and generally, one becomes dominant. As it matures, it produces estrogen, which leads to signs of heat and triggers production of hormones which lead to ovulation. At the ovulation site, a structure called the corpus luteum develops. This structure produces progesterone, or the hormone of pregnancy. If the cow does not become pregnant, another hormone, prostaglandin, is produced. This destroys the corpus luteum, and the whole process starts over.
A follicular cyst might be thought of as a rogue follicle that doesn't ovulate as it should. It is a large, soft structure on the ovary that produces hormones including estrogen. That leads to intermittent signs of heat and other bizarre behavior. These cysts may resolve on their own, but many require treatment.
Luteal cysts are thick-walled structures comprised of luteal tissue. They produce a large amount of progesterone which creates anestrus or lack of an estrus cycle.
Ideally, cattle showing abnormal heat cycles or lack of heat should be examined by your veterinarian. Follicular cysts are typically treated with either GnRH (Cystorelin, Factrel, etc.) or HCG (human chorionic gonadotropin). Treatment leads to ovulation and formation of a corpus luteum. Then prostaglandin (Lutalyse, Estrumate, etc.) can be given to restart the estrus cycle. Luteal cysts should respond to prostaglandins.
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Will this cow have a problem getting bred next year? I have not noted that beef cows tend to have recurrent cysts. Hopefully, this cow will never have this problem again. As a side note, a genetic tendency for this has been established in dairy cattle.
Readers Talk Back:
After many years feeding sale barn cattle, I've gained some experience detecting sick calves. I've found you can pick out all the sick ones sometimes, most of the sick ones sometimes, but you can't pick out all the sick ones all the time. I like to look over a new load while they eat, slowly walking through the lot. If they are spooky, you can't do it. Sometimes, you can go through them on a horse or in a truck, but if that doesn't work, you are already in for a lot of work. Run them all through the gate and check them one by one. Here's what I look for:
> grinding teeth (always sick)
> a humped back, drooping ears and head,
> hard breathing
> not eating enough
> off by itself
> lying down with its neck out
> a snotty nose
> dull eyes
> constant coughing
There may be something here you haven't thought of. My age is 91, and I'm quitting. I hope this helps someone. - James Smith, Illinois
Please contact your veterinarian with questions pertaining to the health of your herd. Every operation is unique, and the information in this column does not pertain to all situations. This is not intended as medical advice but is purely for informational purposes.
Write Dr. Ken McMillan at Ask The Vet, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email email@example.com.
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