Question
I own a 16-year-old Hanoverian broodmare that is allergic to soy. Has there been any research on soy allergies in horses, specifically broodmares?
Answer
Most of the research on soy that involved broodmares was completed a long time ago and investigated the ability of the high-quality protein in soy to meet the amino acid requirements of broodmares and growing horses.
I am not familiar with any research that addresses food allergies to the proteins in soy specifically. Unfortunately, almost every commercial horse feed will have some product of soy, whether it is soybean meal, soy hulls, or soybean oil. If you plan on breeding your mare, you may want to consider alternative sources of protein, like alfalfa (lucerne) as hay, cubes, or pellets.
Further reading on the subject of protein needs and protein sources:
