The basic food covers the horse’s minimum requirement for energy, amino acids, vitamins and minerals. It doesn’t take into account horses’ performance needs and how to maximize them, however, explained Jyme Nichols, PhD, an equine nutritionist and director of nutrition at Bluebonnet Feeds and Stride Animal Health.
“Functional nutrition (essentially an individual diet based on the health and lifestyle of the horse) is particularly important for horses under stress,” said Nichols during her presentation at the EquiSummit 2021 conference, held virtually and sponsored by Kemin.
In her talk, Nichols identified some of the greatest stressors in horses: exercise, transportation, and heat.
Stress, she said, has a direct impact on four things that a functional diet can support:
- The microbiome. The microorganisms that make up the microbiome convert hay and pasture into volatile fatty acids that horses use for energy. In addition, the gut controls about 70% of the immune system. Therefore, optimizing microbiome health is a major focus in horse nutrition, and certain probiotics could help.
“The Bacillus subtilis PB6 probiotic is unique in that it survives the acidic gastric environment when given orally,” said Nichols.
It also survives pelleting, which is important in feed production.
“B. subtilis PB6 inhibits horse-specific pathogenic (disease-causing) bacteria,” she added. “It also helps maintain a good balance of intestinal microflora, which promotes a more robust immune system and helps horses deal better with stress.”
- The intestinal lining. The single layer of cells (enterocytes) that lines the intestinal tract plays a huge role in immunity, she said. The volatile fatty acid butyric acid and zinc support this healthy barrier.
“Failure of the intestinal barrier results in a leaky gut, which allows pathogens, bacteria and undigested nutrients into the body,” she said. “This in turn leads to intestinal inflammation, systemic inflammation and a hyperreactive immune system.”
Feeding butyric acid and zinc, according to Nichols, can improve tight junctions between enterocytes to help strengthen the intestinal lining and support the horse’s immune system.
- The immune system. Beta-glucans, found in the cell walls of yeast, oats, mushrooms, and even algae, have immunomodulatory effects, Nichols said. Algae have a particularly high concentration of very useful beta-glucans, i.e. those with 1,3-linkages between individual sugar molecules.
“These unique chains of sugar molecules prepare the immune system so that it can respond appropriately. Beta-glucans ward off the underperformance and health challenges we see after transportation and competition, ”said Nichols.
- Cell function. Muscle fatigue occurs after exercise and transportation. Nichols described the transport as a “mini workout” that tires horses before they even come to their event. Fatigue lowers muscle glycogen, the storage form of glucose that powers muscles, and increased protein breakdown in working muscles contributes to early fatigue.
“Chromium (an essential trace element) helps replenish glycogen in muscles to help fight fatigue more efficiently,” said Nichols. “This nutrient improves glucose uptake and conversion to glycogen and plays a role in the body’s response to heat stress.”
As mentioned earlier, heat is a major stress factor for horses. It increases a horse’s core temperature, increases metabolic rate, causes sweating and electrolyte depletion, and changes the way the body metabolizes nutrients, including glucose and lipids (fats).
“Chromium improves the capillary function of the skin and improves heat dissipation,” says Nichols.
Take home message
To maximize a horse’s potential, owners must consider functional nutrition in addition to genetics, training, and general management. Functional nutrition fills the gap between the feeding of feed, grain and nutritional supplements that make up the basic food pyramid.