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Vet Segment from The Horse Talk Show


Audio Transcription from January 7, 2017- Dr. Phil Matthews


Lengthening the Day

I always try to simplify things for my clients and in my mind, so I put all mares in 3 categories:


1)    Maiden Mare (never had a foal)

2)    Barren Mare (not pregnant but has had a foal)

3)    Foaling Mare (who is in foal)


For our discussion today, we will leave out in Foal Mare; the other two categories are the Maiden and Barren Mare. But I think what people need to think about if they are novices in the breeding world, is that the mare is a seasonal breeder. About 80-90% stop cycling during the winter months, and that’s a function of the daylight (photoperiod) when the days become short. This triggers a hormone in the brain and the brain shuts their ovaries down. If we want to breed our mares in February and early March, we have to trick them and have to get them to think that daylight is getting longer by using artificial lights. That’s an important component in trying to get early foals.


There are several ways to do that but essentially what you’re doing is lengthening the daylight (photoperiod) in each day, the simplest and first way that was ever designed works well. It was to extend the normal length of day to about 11 pm so they have about 16 hours of total light. A simple way to do that is to bring up your mares up to the barn at night and set a timer on your light switch to go out at 11 pm. An important part to note is that 24 hours of light does not work; they need to have some darkness. In about 6-8 weeks, they will begin to have ovulatory cycles and be ready to breed. There have been other systems, but this older system is the one I like and one that works well. There are other ways that people can learn and discover if they want, but this one is pretty easy.


Using a Commercial Product

From a technology standpoint that’s out there, is a commercial product called Equilume that is a mask and we actually talked about it last year on the program. The mare can continue to live outside and has a battery operated light that functions in the right eye. It is a blue light, but it is not harmful and will go off at 11 pm at night; you can do the same thing without having to bring the mare up to the barn and trying to use a lightened barn.


There are other procedures for people who do not have to use live cover breeding, and Peterson & Smith offers Embryo Transfer Program that provides another option for breeding.


Stepping Out Into New Technology

There are different semen choices, and you can breed shipped cooled semen, and that can come from all over the United States. If you opt to breed frozen semen, and it’s cared for properly, it can virtually last forever. That semen can come from all over the world, and that really expands your options.


There are other categories of assisted reproduction procedures that go beyond an artificial insemination and it involves embryo transfer ICSI (which is an acronym for In Vitro fertilization). Embryo transfer has been around since the late 70s-early 80s on a commercial level. It’s been around for a long time now and we are very successful at it on an industry level. It expands genetics, while you can have a performing mare who you don’t want to interrupt her with a pregnancy. You can breed her and you flush the embryo out of her just a few days later, and put that embryo in a surrogate or recipient mare. You may have an older mare or a mare that is unable to carry her own pregnancy, lame, or and ill mare.


ICSI is a step further in technology, and that’s where we go into the mare’s ovaries directly, bypass the rest of the reproductive tract and we take eggs from her ovaries directly. We then take them to the laboratory, fertilize them with a sperm cell in the laboratory, grow the embryo in the laboratory, then transfer the embryo into the surrogate and recipient mare. It’s an alternate for some mares that we are unable to get embryos at all due to reproductive issues; it expands the options to the genetics of your mare.

Final Thoughts


Your veterinarians can help you quite a bit in this process. One thing I tell the veterinarians I engage with is that the best service I can give to my client is to treat every cycle like this is the cycle that we are going to get pregnancy. So we throw all our eggs in that basket for each cycle. I can save people money the faster I can get their mare pregnant. Breeding mares is an expensive endeavor and something I don’t take lightly; I want them to have success with the least costs they can possibly have. Once you decide to breed your mare, go all in and get the process started.


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