Featured Research

from universities, journals, and other organizations

Pregnancy in horses: Helping horses come to term

Date:
August 2, 2013
Source:
Veterinärmedizinische Universität Wien
Summary:
It is not only humans that sometimes experience difficulty having children. Horses too have a low birth rate, with many pregnancies failing within the first few weeks after conception. The reason is currently unknown but recent research suggests that a particular class of blood cells may be involved.

Mare with her new foal.
Credit: Copyright Vetmeduni Vienna/C.Aurich

It is not only humans that sometimes experience difficulty having children. Horses too have a low birth rate, with many pregnancies failing within the first few weeks after conception. The reason is currently unknown but recent research by the team of Christine Aurich at the University of Veterinary Medicine, Vienna (Vetmeduni) suggests that a particular class of blood cells may be involved.

The results have just been made available online in the journal Reproduction, Fertility and Development.

As any nervous first-time mother will confirm, the initial three months of pregnancy are the most risky time: many expectant women are reluctant to inform their friends or colleagues that they are pregnant until after this period is past. It is less well known that horses suffer from similar problems, with a considerable number of pregnancies failing to progress beyond the first five weeks. The explanation is still unclear but may relate to a problem with the mare's immune system, as the latest work in the group of Christine Aurich in the Vetmeduni's Centre for Artificial Insemination and Embryo Transfer strongly suggests.

The fertilized egg, or conceptus, obviously contains contributions from the stallion as well as the mare, which means it somehow has to avoid being recognized and attacked by the mare's immune system. Horse breeders talk about maternal tolerance of the conceptus and horses -- as other animals -- have a variety of mechanisms to enable fertilization and a successful pregnancy. Maternal tolerance probably depends on wide-ranging changes to the maternal immune response. But what makes some mares better than others at adapting their immune systems?

There are indications from work in humans and mice that a particular class of immune cell, the so-called regulatory T cells or Tregs (pronounced "tea regs"), might somehow be important in maternal tolerance. Aurich and her colleagues have now developed a highly sensitive assay to measure the proportion of Tregs in the blood of horses. They used their new technique to investigate over 100 mares that were presented for artificial insemination, correlating the results with the outcome of the resulting pregnancies.

Of course, not all of the animals conceived. The scientists could find no association between the level of Tregs in the mares' blood with the success of the insemination procedure. However, they did observe clearly lower numbers of Tregs in the blood of horses that suffered an early loss of pregnancy compared with those that either aborted much later (for whatever reason) or gave birth to live foals. The results suggest that high numbers of Tregs might somehow be required to suppress the mare's natural immune reaction against the conceptus. In other words, low levels of Treg cells in mares might cause pregnancy loss in the five weeks after fertilization.

The differences in the levels of Tregs between horses in the "successful pregnancy" and the "unsuccessful" groups were too small to be useful to predict whether an individual mare is likely to suffer early pregnancy failure. Nevertheless, the results may help breeders solve the problem. There is evidence from human medicine that oestradiol may enhance the function of Tregs during pregnancy and treatment with this hormone could possibly benefit mares prone to losing the conceptus. Another possible course would be to expose mares to the stallion's semen before implantation, which might increase the number of Tregs in the blood and the animal's tolerance to the conceptus, thereby helping avoid early pregnancy losses.

Aurich is optimistic: "A number of reasons have been proposed to account for early pregnancy failure in the horse but our work suggests that a low level of Tregs may actually be among the most important factors. It can only be a matter of time before we find out how to solve the problem."


Story Source:

The above story is based on materials provided by Veterinärmedizinische Universität Wien. Note: Materials may be edited for content and length.


Journal Reference:

  1. Christine Aurich, Jurgen Weber, Christina Nagel, Maximiliane Merkl, Rony Jude, Sascha Wostmann, Dirk Ollech, Udo Baron, Sven Olek, Thomas Jansen. Low levels of naturally occurring regulatory T lymphocytes in blood of mares with early pregnancy loss. Reproduction, Fertility and Development, 2013; DOI: 10.1071/RD13012

Cite This Page:

Veterinärmedizinische Universität Wien. "Pregnancy in horses: Helping horses come to term." ScienceDaily. ScienceDaily, 2 August 2013. <www.sciencedaily.com/releases/2013/08/130802080235.htm>.
Veterinärmedizinische Universität Wien. (2013, August 2). Pregnancy in horses: Helping horses come to term. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2013/08/130802080235.htm
Veterinärmedizinische Universität Wien. "Pregnancy in horses: Helping horses come to term." ScienceDaily. www.sciencedaily.com/releases/2013/08/130802080235.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

AP (Oct. 17, 2014) — Two white lion cubs were born in Belgrade zoo three weeks ago. White lions are a rare mutation of a species found in South Africa and some cultures consider them divine. (Oct. 17) Video provided by AP
Powered by NewsLook.com
The Best Foods To Boost Your Mood

The Best Foods To Boost Your Mood

Buzz60 (Oct. 17, 2014) — Feeling down? Reach for the refrigerator, not the medicine cabinet! TC Newman (@PurpleTCNewman) shares some of the best foods to boost your mood. Video provided by Buzz60
Powered by NewsLook.com
Sweet Times for Hard Cider Makers

Sweet Times for Hard Cider Makers

AP (Oct. 16, 2014) — With hard cider making a hardcore comeback across the country, craft makers are trying to keep up with demand and apple growers are tapping a juicy new revenue stream. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Meet Garfi the Angry Cat

Meet Garfi the Angry Cat

Buzz60 (Oct. 16, 2014) — Garfi is one frowny, feisty feline - downright angry! Ko Im (@koimtv) introduces us to the latest animal celebrity taking over the Internet. You can follow more of Garfi's adventures on Twitter (@MeetGarfi) and Facebook (Garfi). Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins