December 23, 2004

Scientists get horses to eat fish oil with 'cookies'

by K.C. Jaehnig

CARBONDALE, Ill. -- A diet that includes fish oil has all sorts of health benefits — from increasing exercise tolerance to boosting the immune system. But will something that helps humans work for horses, too? Four animal scientists from Southern Illinois University Carbondale decided to find out.

"We wanted to know how much of this stuff they had to eat to get it circulating in their bodies in high enough concentrations to get those good benefits," said Sheryl "Sheree" S. King, who runs the College of Agricultural Science's equine program.

"I also questioned whether the horses would eat it. They're not picky eaters, but they are vegetarians. The first step was to convince horses to eat fish."

Homemade "horse cookies"— made of molasses, oats and powdered fish oil combined in giant mixers at the University's farms — did the trick.

"They were crunchy, though they still smelled fishy," King said. "I thought the horses wouldn't touch them — but they did."

For this project, King and colleagues Amer AbuGhazaleh, Gary A. Apgar and Karen L. Jones divided 16 mares of different breeds, ages and weights into four groups. Once a day during February 2004, the scientists fed each group cookies made with different amounts of fish oil. They took weekly blood samples during that month and the following three months as well, looking for traces of Omega-3 fatty acids — the active ingredients in fish oil — both in the blood plasma (the liquid part) and in the red blood cells, where effects are thought to last longer.

"We found that the specific Omega-3 fatty acids that are the most beneficial to health did get into the red blood cells, and their concentrations were roughly equivalent to the amount the horses were eating — the more they ate, the higher the concentration," King said.

"It did take a very long time for the concentration to increase. We didn't actually see it until after we had stopped feeding the product, but it stayed around much longer there (59 days after they stopped giving horse cookies) than it did in the plasma."

In addition to measuring levels of eicosapentaenoic acid and docohexaenoic acid, the two most helpful fatty acids, the team also recorded concentrations of 34 other Omega-3s. While most of these concentrations did not increase, King said the measurements still had value.

"We now have a data bank on the horse that nobody else has," King said.

"We know what fatty acids are circulating in the horse. Researchers who come after us who want to manipulate these acids in horses will be able to look at our data and know what the horse has naturally."

The researchers presented their findings in a poster session at the annual Equine Science Society meeting held May 31 through June 3 in Tucson, Ariz. They are now analyzing data from a second fish oil study to see if Omega-3 fatty acids can induce ovulation in mares.

Leading in research, scholarly and creative activities is among the goals of Southern at 150: Building Excellence Through Commitment, the blueprint for the development of the University by the time it celebrates its 150th anniversary in 2019.