I have recently had some calls and emails pertaining to low sugar diets for horses and I had never thought about that being an issue but with the increase of metabolic disorders like insulin resistance leading to laminitis, a painful breakdown in the bond between the hoof and underlying bone, it is a very serious issue.
So, in order to educate myself on the issue I dove into the research and it turns out there has been quite a bit done, mostly in the North and East United States. I will begin by saying that it is impossible to give an average nutritional content of forage in this area or any area, testing is the only way. Not only testing but it must be specific testing that is only done by a few labs that I am aware of.
Normally our horse rations consist of a concentrate grain feed and roughage. Concentrate grain feed can consist of sweet feed oats to soybean hulls and have their own place on the glycemic scale. The glycemic scale gives us the same information concerning blood sugar weather we are relating it to human nutrition or equine nutrition. Forage and hay on the other hand is a little harder to lock in to a hard and true scale because of all the variables.
Our two main hay types are warm season and cool season forages are at each end of the spectrum concerning carbohydrates and Fructan. We can say with some certainty that cool season forages and hay contain more Fructan, a type of carbohydrate that plants accumulate, than warm season forages and native prairie hays are the lowest. Ideally horses should get most of their nutrition from roughage and be supplemented with grain. The amount of hay is based on the size of animal consisting of 1-1.5 % of the animal’s body weight. Most of the research I have read recommends five pounds or less of grain per day split up into four or five feedings. Again, all of this is dependent on the horses requirements based on activity and life stage. The more frequent feedings cause the animal to produce more saliva which acts as a chemical buffer for stomach acids. Less saliva can mean increased bacterial growth and the possibility of gastric ulcers compounded by colic or stomach wall rupture.
It is also necessary that we slow down the rate at which the feed and roughage pass through the digestive tract. Feed only takes about 15 minutes to begin emptying out of the stomach and between an hour to an hour and a half to make it through the small intestine. The hindgut is where the ingesta must spend most of its time, about three days. Moving more rapidly can lead to decreased digestion, laminitis and colic. The main way to slow this is by increasing roughage consumption and decreasing grain intake.
Choosing low sugar and low carbohydrate feeds and low fructan forages can go a long way to keeping your horse healthy. Using the glycemic index we identified that wheat bran, beet pulp, alfalfa, rice bran and soybean hulls are lowest on the scale. Equine nutritionists and feed company representatives are available to give more information on feeding your horse correctly. Contact me at 940-349-2889 for more information on laboratories for forage analysis and general questions.
Janet Laminack, Denton County Extension Agent –Horticulture/Texas A&M AgriLife Extension, 940-349-2883, firstname.lastname@example.org