Saturday, March 28, 2009

Equine Research Texas Style


I recently returned from visiting my daughter in College Station, Texas where she is a graduate student at Texas A & M in Equine Exercise Physiology. She is in the last few weeks of the actual fifteen-week test period of studying the role of magnesium in the phenomenon of tying up in horses. I’ve often commented that conducting this kind of research on horses is not like studying rats or mice in the laboratory. Prior to the start of the test period Cassidy had to break six horses to drive and pull a sled which would eventually be loaded to create particular levels of stress on each horse.

She fondly refers to the two groups of three horses as Team A and Team B. Team A, including Frenchy, Daisy, Sahara, are the well-minded cooperative mares who don’t mind their life as research horses: fed twice a day with custom grain and hay rations, allowed outside for a short time each day, and then exercised lightly in the evenings. The B Team consists of three mares that don’t particularly care for their job as research horses. They include Pizzaz, Chance, and Juno. Pizzaz has never warmed up to her job and Chance was frightened one day when the hitch came unhooked and banged against her hind legs until Cassidy and her assistants could get her stopped. Only recently did she begin to calm down while pulling the sled.

Her project consists of exercising each horse three days a week by driving the horse as it pulls a weighted sled. Each horse wears a heart rate monitor during the 15 minutes of warm-up, actual pulling of the sled, and warm-down. During the active phase Cassidy wears a watch that receives the monitor’s information and allows her to drive at a pace that maintains a specific heart rate for each horse. Depending upon the size of the horse, various buckets of weights are added to the sled. With the A Team Cassidy will actually make herself a part of the weight and sit on a bucket on the sled. With the B Team, she will weight the sled with buckets and walk and, or run behind to keep the exercise period safe with the horses that aren’t consistently comfortable pulling the sled.

Once every four weeks, the horses are stressed on a treadmill for thirty minutes and monitored for fatigue. Typically fatigue occurs at or around 220 heartbeats per minute (bpm) in horses. She is also monitoring heart rates every five minutes to look at levels of conditioning over the entire test period of three months as well as any differences due to other factors, including diet. Most importantly, the horses are monitored for signs of tying up, which include rapid increase in heart rate, excessive sweating, reluctance to move, stiffness, and firm or hardened muscle groups.

Blood samples are drawn before, immediately after, 1 hour post, 6 hours post, and 24 hours post the treadmill test. Blood serum is assessed for levels of muscle enzymes and serum levels of magnesium. Previous research has suggested that an increase in muscle enzymes is indicative of muscle breakdown or damage as a result of exercise. Cassidy is also looking at how a diet deficient in magnesium (Mg) or supplemented with Mg may affect these levels.

Cassidy looks forward to the end of the test period when she can begin to analyze her data. When I asked her what she’d learned so far, she replied, “Research on live animals is unpredictable and impossible to completely control. However, it’s (obviously) beneficial because it applies to real life experiences of the performance horse.” She also offered these words of wisdom about her research experience, “Do not use unbroken horses. It’s difficult to set up the perfect project with live animals. Outside factors are hard to control, harder to predict” Although she looks forward to the day she defends her research and thesis, her own fatigue from the demands of her work led her to offer one last tongue in cheek suggestion that perhaps one should never “freely choose or volunteer to do research” in the first place.

I know in August she will have a different perspective on her research experience. As the horses have been conditioned and strengthened, so has Cassidy. For often it’s in the doing that we discover elements we didn’t know we were searching for. Perhaps, an uncontrolled, unforeseen element of the practical side of the research, like an illness or lameness; or an unpredicted physiological phenomenon; or in Cassidy’s case, a new awareness of her ability to survive the physical demands of managing and handling her research horses, accurately collecting data, and carrying out her roles as teaching assistant and student from 5:30 AM until the wee hours of the next morning every twenty-four hours for three months.

As with Lena and Candy, this story too will be continued when the final research project is given birth on the day she defends her work late this summer.

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