Young horses may be easier to train if they temporarily lay off sweets foods. A commercial mixture of corn, oats, barley and molasses, sometimes "sweet feed," gives horses a glossy coat and lively spirit. But the extra energy provided by sweet grain during can also make the horses more disobedient and fearful than horses that only eat hay.

In a recent study, horses fed on “sweet feed” spent more time resisting the saddle, startled more easily, and bucked and ran more during training.

The study involved 12 closely-related quarter horses that came from one Idaho ranch. The horses were trained for three weeks, five days a week. Half the horses ate only hay, a mixture of grass and alfalfa. The other horses ate five pounds of sweet grain a day in addition to the hay. Both groups ate as much hay and drank as much water as they wanted.