Good Diet, But Lacks E-Se, Iodine

I have two Thoroughbred mares, both ex-racehorses aged 15 (15.2 hands, 1,150 lbs.) and seven (16.1 hands, 1,250 lbs). Both are hard keepers and ridden two or three times per week one hour or less, with the elder engaged in light hunting two to three times per month October through March. Oil and bran are out as supplemental feeds due to palatability.

The seven-year-old has had one episode of laminitis but has excellent hoof growth. The 15-year-old has stomach ulcers, osteoarthritis and slow, high-quality hoof growth. Otherwise they are healthy and sound.

Both mares are at on a six-acre pasture of mixed fescue, orchardgrass, and clover grasses 12 to 24 hours per day, weather permitting. When stalled and during the winter, they receive unlimited quantities of fresh orchard grass and clover mix hay. At no time are they without unlimited hay or pasture. Occasionally they receive a small portion of alfalfa.

Based upon your September 2001 article on mineral supplements for fescue and orchardgrass, which implies I may be underfeeding calcium, I am considering making alfalfa a regular part of their diet.

In addition, they each receive eight pounds of grain each day, half Southern States Equitech-10 textured sweet feed and half Triple Crown Senior. I also give them Accel, VetEx dl-Methionine With Biotin And Zinc hoof supplement, and Horseshine ground flaxseed. They have salt and mineral blocks. Am I over or under supplementing vitamins or minerals anywhere’

-Torun Willits

Since your horses are typical Thoroughbreds, even with eight pounds of grain per day they are probably eating about 15 lbs. of hay.?? If your hay averages 20-25% clover, you don’t have any problems with calcium.??In fact, your grain products are giving them their total daily requirement of calcium and phosphorus, which corrects the deficit in the orchardgrass. Like alfalfa, clover is extremely high in calcium.

We would add 1000 IU of vitamin E and 1 mg. of selenium to the diet, since both of these are currently low in the diet. The iodine intake is probably also low or borderline and, while the total amounts of the other trace minerals (copper, zinc and manganes) are well above minimum, there’s a significant imbalance because of the relatively high manganese in your hay compared to zinc and copper.??Your hoof supplement helps bring this into line but leaves you short on copper and iodine.??Changing to Su-Per Farrier’s Formula from Gateway (800/421-2828) would correct both and has an excellent methionine level.

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