OklahomaHorses Magazine November 2021

November/December 2021 • OklahomaHorses 19 By Lindsay Humphrey C ontrary to popular belief, horses go through two different hair growth seasons. The most recognized is when the days get shorter and temperatures drop in the fall, and horses out in the elements will begin building their winter coats. The second is in the spring, when horses slick off and shed that same winter coat. The decision to blanket or not typically hinges on five factors: age, haircoat, living situation, body condition score (BCS) and geography or local weather conditions. People and horses have a different lower critical temperature threshold that determines when their body will begin burning extra calories to maintain their core body temperature. These five factors will help deter- mine if that threshold is above the average. THERMOREGULATION MECHANICS “Horses actually thermoregulate themselves really well natural- ly,” said Dr. Kyre Larrabee, a mixed animal veterinarian at Gray County Veterinary Clinic in Pampa, Texas. “Similar to when people get cold and have goosebumps, horses do basically the same when they’re cold. When their hair stands up, it helps trap air in their coat, and their body heats that air and provides insulation.” The lower critical temperature for a horse with a good body condition, adequate quality forage and shelter or a wind block is between 41 and 86 degrees. This range can differ for older and younger horses, those with a performance or clipped coat and any of your “hard keepers.” Larrabee grew up on her family ranch in southwest Kansas, where horses were on pasture 24/7. It wasn’t often that these horses were kept at home in the corrals during the winter months. “Our biggest concern was making sure everyone had a good body condition score, plenty of forage and opportunities to get out of the wind,” she explained. “We always made sure they had everything they needed, and they did just fine turned out on pasture without blankets.” Some of the mechanics of thermoregulation change a bit when a horse is burning additional calories through regular exercise. This fact changed how Larrabee approached blanketing when she went to college at Oklahoma State University and started competing on the Cowboys’ rodeo team. or Not To Blanket