The latest Horse Course from the University of Kentucky’s Veterinary (UK) Diagnostic Laboratory and Gluck Equine Research Center (presented by Pfizer Animal Health) is now available for viewing on TheHorse.com.

The presentation, "Muscle Power: Muscle Mass in Growing, Athletic Horses," was led by Kristine Urschel, PhD, assistant professor of equine science at UK. Urschel discussed the management of muscle mass in growing equine athletes and in aging horses, including dietary considerations such as protein and "muscle-building" supplements.

"In horses, about 40%-55% of their mature body weight is skeletal muscle; this is a huge number compared to other species," Urschel said during her presentation. "Of that muscle … about 70% is water. But of the nonwater component, by far the greatest component is protein. About two-thirds of the nonwater is made up of protein.

"The muscle protein, which is what we’re going to be focusing a large part of this on, has structural properties," she continued. "It’s what … actually does the contractile function of skeletal muscles, so when we think about muscle protein, that’s what we usually think about. But there’s an entire other subset of proteins in the muscle that are equally important, and those are the ones with the metabolic role