Hoof Nutrition Intelligence is a twice-a-month web segment that is designed to add to the education of footcare professionals when it comes to effectively feeding the hoof. The goal of this web-exclusive feature is to zero in on specific areas of hoof nutrition and avoid broad-based articles that simply look at the overall equine feeding situation.
Below you will find Part 2 of the latest question and answer installment that you can share with your footcare clients.
Q: Is feeding sulfur essential for maintaining hoof quality?
By Eleanor Kellon, VMD
You have probably read at least one article talking about sulfur in the body as indispensable for protein production, for the integrity of skin, hair, hooves and nails, its enzyme action, its presence in important B vitamins, for the production of substances like chondroitin sulfate and its role in the elimination of toxins.
All of that is true, but confusion reigns about how you should supply it.
If you are from Australia or South Africa, you may have been told horses should be supplemented with inorganic elemental sulfur. Regardless of where you are from, you probably have read that MSM or DMSO are sources of organic sulfur that will be available to perform all the important roles of sulfur in the body.
Both are incorrect, as horses may utilize small amounts of the sulfate ion present in their diet and water. However, their main source of sulfur, and the only form utilized by proteins and insulin, is the sulfur containing amino acids, the most important of which is methionine. This can be converted to cysteine and from there to cystine — the other two structurally important sulfur amino acids.
The horse can’t make methionine from sulfur or MSM/DMSO — it has to be present in the diet. While the true equine requirement for methionine is unknown, it is thought to be between 15%-33% of the lysine requirement.
Forage is the major source of methionine. The National Research Council has recommended a sulfur intake of approximately 0.15% of the diet dry matter, although there is evidence this amount may be inadequate. Good quality hay grown on soil with adequate sulfur should meet the requirements of at least maintenance and low-level exercise if there are no special needs. However, there is a growing problem with this.
Sulfur was routinely incorporated into fertilizers until increasing industrialization began sending large amounts of sulfur into the air. This “acid rain” provided an excellent source of free sulfur for plants, but caused many other problems. However, sulfur emissions from, power plants have been tightly regulated since the ‘80s and ‘90s, with the result that the amount of sulfur found in the soil is dropping.
A hay analysis crossed my desk this week that contained only 0.04% sulfur. These hays will have low protein, low methionine and the potential for high nitrate levels. Taurine is another sulfur amino acid ultimately derived from methionine that plays many important roles in the nervous system, detoxification, liver function and metabolism. Increased levels may be needed by horses with abnormal glucose metabolism to support the body in avoiding harmful interactions of glucose with body tissues, such as nerve damage.
Taurine also helps maintain the neurotransmitters that are responsible for a stable, happy mood. When methionine intake is known to be low, or suspected from issues like poor hoof quality, supplementation of 5,000 to 10,000 mg (5 to 10 grams) per day for the average size horse is reasonable. For situations that may benefit from taurine support, this can be supplemented in similar amounts.
Dr. Eleanor Kellon, a staff veterinary specialist for Uckele Health & Nutrition, has been an established authority in the field of equine nutrition for over 30 years. The owner of Equine Nutritional Solutions in Robesonia, Pa., she is a founding member and leader of the Equine Cushings and Insulin Resistance (ECIR) group, whose mission is to improve the welfare of horses with metabolic disorders via integration of research and real-life clinical experience. Prevention of laminitis is the ultimate goal.
Hoof Nutrition Intelligence is brought to you by W.F. Young Co. (Absorbine).
Like many significant achievements, Absorbine® grew out of humble beginnings—and through the tenacity of someone willing to question the status quo. In this case, it was a young woman in late 19th-century Massachusetts: Mary Ida Young. Her husband, Wilbur Fenelon Young, was an enterprising piano deliveryman who relied on the couple’s team of horses to make deliveries throughout the Northeast. Inspired by Mary Ida and Wilbur’s vision, Absorbine® has continued to add innovative products throughout the years — products used every day by horse owners around the world. Which is why, since 1892, we’ve been The Horse World’s Most Trusted Name®.
Click here to read Part 1 of the Oct. 15, 2018 installment: How much should I involve my farrier with the nutrition of my horses?