Concepts for Safe & Effective Feeding
Many horse owners are unaware of the effects of our most common feeding habits. Feeding large meals, and excess dietary carbohydrates can cause problems for our horses. All horse owners can understand the basics of a horse's digestive system, and learn to feed accordingly. Lets learn to spot the symptoms of a nutritionally compromised horse.
1. Poor hair coat,
2. Thin, shelly, brittle hoof walls, hooves that have ripples and bumps
3. If your horse is an "Easy Keeper" aka obese
4. If your horse is a "Hard Keeper" aka thin
To adequately address our horse's nutritional needs we must understand the normal function of the gastrointestinal tract, and how horses were designed to eat in a natural setting.
Horses are designed to forage on high fiber plants for 18-22 hours a day. Foraging means that horses are constantly seeking out food sources, using their minds, and traveling most of the day to get to food sources. Horses forage on plants high in fiber and very low in non-structural carbohydrates (NSC). NSC is a combination of sugar and starch.
To digest plant material horses must rely on a population of digestive bacteria that live in the hindgut. A plant's nutrients are contained inside tough outer structures such as Pectin, Cellulose, and Hemi Cellulose. The function of digestive bacteria is to breakdown the tough outer shells of plants and convert complex plant structures into usable energy for the horse. These bacteria populations exist in a delicate balance with one another.
When a food source enters the gut, digestive bacteria increase in numbers. As the food source leaves the body the digestive bacteria begin to die off. When sugar digesting bacteria die off, they release endotoxins(from their bodies) and exotoxins (from their outer shells). These toxins are damaging to the horse. However, in a natural setting,(when the horse is foraging continuously for 18-22 hours) this influx of food and subsequent die-off of digestive bacteria, is not harmful to the horse. In a natural setting the horse is eating high fiber plants and the sugar digesting bacteria exist in small populations.
The Fallout from Feeding Habits
It should be clear from looking at the G. I. tract that horses are not meal eaters. Horses have small stomachs and long intestinal tracts. However, we typically feed horses with two or three large meals a day. This feeding of large meals, and the high carbohydrate content of the meals, causes multiple problems for the digestive system.
Feeding meals causes a dramatic increase in the populations of digestive bacteria. After several hours, when the food source leaves the body the digestive bacteria die off in mass. Confounding the problem, the hay we feed is frequently too high in NSC (non-structural carbohydrates). Feeding this type of starch rich hay can cause an increase in the population of sugar digesting bacteria, in particular a bacteria called Streptococcus Bovis. When Streptococcus Bovis bacteria climb into high levels and then die off, they release levels of toxins that are damaging to the horse.
Additionally, Streptococcus Bovis ferments carboydrates into Lactic Acid which decreases the ph of the hind gut. Changes in hind gut ph will kill off the "good" fiber digesting bacteria. Now, no matter what we feed the horse, he will have trouble getting adequate levels of nutrients. Horses that have been thought of as just "hard keepers" may actually be suffering the effects of excess dietary carbohydrates.
Horses who have suffered severe carbohydrate overload,(after busting into the grain room),will typically suffer an acute episode of laminitis from the massive die off of bacteria, and subsequent toxin exposure. This is not hard to spot and a tragedy whenever it occurs. More common (and harder to spot) are horses routinely fed excess carbohydrates and living with the damaging effects "under the radar" . Poor skin, coat, and hooves are some red flags that all horse owners should watch out for.
Changing Our Habits
For most people feeding in a truly natural way isn't possible. However there are ways to slow a horse's ingestion of hay. Some excellent solutions are to feed out of hay nets or slow feeders. This stops the "hoovering" in of food, and thus mimics a natural, slow and steady influx of food.
Additionally, feeding hay that is lower in NSC is desirable. Grass hays containing around 10% NSC serve as a good nutritional base for most horses. Remember when feeding...you aren't just feeding your horse you are nourishing and developing the digestive bacteria in the hind gut. The health, balance and stability of the digestive bacteria are crucial to your horse.
For more information on diet and feeding, go to SaferGrass.org.
Ann Ramsey BS, CERA, APF-I -2019
Consult with a Veterinarian about specific medical nutritional needs. This is not meant to be a replacement for Veterinary consultation or care. It is not meant to diagnose, treat, or cure any disease or ailment. This article is only a general exploration of the effects of excess NSC on the equine digestive system.