On Plump Pregnant Mares

The small item on page 19 of the September issue, “Fat = Less Fertile,” is misleading and perhaps erroneous. I’m not aware of scientific evidence proving excessive body fat is detrimental to fertility or parturition in the mare. To the contrary, colleagues and I have published research showing that excessive body fat in the mare is not detrimental to conception, pregnancy, parturition, or postpartum reproductive performance. The only negative effect of excessive body fat in mares that we found was a slight reduction in milk production, perhaps due to fat accretion in the udder.

While I don’t advocate mares’ being fed to obesity, neither do I advocate scaring horse producers about mares becoming too fat—regarding fertility. The risks of laminitis are very real when horses eat enough high-quality feed to cause excessive body-fat storage, so that situation should be avoided if possible. But that situation is not detrimental to fertility.

GARY D. POTTER, PhD, Arkansas

Editor’s Note: Dr. Potter is professor emeritus of Texas A&M University. For citations to the scientific research he references in his letter, contact him at 10247 East McNelly Road, Bentonville, AR 72712.

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