Electrolytes May Solve Heat-Intolerance Problem

My Dutch Warmblood mare, age 6, and I live in the mountains of Utah at 6,000 feet above sea level. We compete in California, Colorado, Arizona and Utah. She is 16.2 hands with no apparent health problems.

Her morning feed is 3 scoops (each scoop equals 2 cups) of Omolene 200, 2 oz. of Horse Tech BioFlax 20 and 1 scoop of Strongid C2X. In the evening, the grain is the same. She gets 2 flakes of grass-alfalfa hay three times per day and pasture all night.

She’s in dressage training one to two hours a day, four or five days a week and is trail ridden in the mountains one day for three to four hours. She gallops a cross-country course twice a week during the summer. She does not tolerate heat well (neither do I). She is a quiet mare and not very touchy when in season. She can gain weight easily.

Should I give her Calf Manna’ When we are in the show ring she is alert, but we have worked hard at alert, relaxed submission away from home. She can be alert or asleep. At home, she is too quiet and seeming without energy even in the winter, but more so in the heat of summer. Should I be doing something else with her feed in relationship to altitude, heat, and training at home versus feed at shows at altitude and sea level’

-S. Shaffer

Horse Journal Responds:

Assuming your mare weighs about 1,200 pounds, and your total hay intake comes to around 20 pounds a day, grain three pounds, you are feeding just slightly under what would be predicted as necesary to maintain her weight, which indicates that she is indeed an easy keeper.

For major minerals, there is an excess of calcium because of the alfalfa, but the ratio with phosphorus is still within what a mature horse should tolerate without problems. Copper, zinc and manganese levels are fine, but selenium and vitamin E should be supplemented (2 – 4 mg/day selenium and 1,000 to 2,000 IU vitamin E). Iodine is also probably low, which could affect thyroid function (as can low selenium). Source may be a good iodine supplement for you. You don’t need to feed Calf Manna. Her protein and trace mineral levels are just fine.

There are no different feeding recommendations related to altitude. Altitude could affect how your horse acts though, since she is acclimated to the “thinner air” now and will feel more energized and work easier at sea level as a result.

Heat is a different story. In hot weather, your mare needs to take in at least 2 to 3 oz. of salt a day, whether she is working or not. If feeding free-choice salt, check her intake by either putting out a measured amount of loose salt or periodically weighing salt blocks. If less than the minimum, she may be total body-salt depleted and probably has adapted to this by becoming chronically dehydrated to some extent. This can definitely make her sluggish, especially in hot weather. If she doesn’t take in enough salt on her own, add the difference to her grain, dividing it between feeds.

On days you are riding her longer than an hour in the heat, it’s also good to supplement with an electrolyte mix designed to replace sweat losses. Salt (sodium chloride) is the most important, since she is getting enough potassium from her diet to support quite a bit of sweat loss.

However, you can speed recovery from sweat losses and help keep her hydration and energy levels up during prolonged work in the heat by using a balanced supplement with sodium, chloride, potassium and small amounts of both magnesium and calcium.

We recommended ExerLyte from Mobile Milling (800/217-4076) in our August 1999 electrolytes article. It is now also available in a paste. However, newcomer Perfect Balance Electrolite from Peak Performance (800/944-1984), also available as a paste, is an even better match to sweat losses.


How Does Your Feeding Program Measure Up’
Tell us what you are feeding your horse and why. What are your concerns’ Don’t forget to tell us what you do with your horse and how hard you work him.All questions should be sent to the editorial offices by regular mail or e-mail: 6538 Van Buren Road, Warners, NY 13164 or [email protected]. We’re sorry, but questions cannot be answered over the phone. All letters will be edited for clarity, content and length.

What did you think of this article?

Thank you for your feedback!