Question
I have been told that dairy quality alfalfa (>20% protein, <30% ADF) is too “hot” for my horse and will cause him to sweat excessively when he is exercised. What are your thoughts on this? Does this type of hay contain enough fiber to meet his needs?
Answer
The term “dairy quality alfalfa” is used to describe alfalfa hay that is high in protein and low in fiber. These are desirable traits in hay intended for dairy cattle because it provides nutrients essential for milk production. Unfortunately, this is not the best hay for performance horses. In general, mature performance horses require a diet that is between 8% and 10% protein. Feeding dairy quality alfalfa hay will provide more than twice the recommended amount of protein in the diet. Excess protein in the diet can be utilized for energy during exercise.
The utilization of protein for energy produces three to six times more heat than the utilization of carbohydrates or fats. This can contribute to excessive sweating and heat exhaustion in performance horses, particularly in warm environments. In addition to being energetically inefficient, high protein diets will also increase the horse’s water requirement. This water is utilized to flush excess nitrogen associated with protein metabolism from the system. Therefore, a diet of dairy quality alfalfa hay is not the best choice for performance horses since it will increase heat and water requirements, two things that any performance horse can do without.
Does dairy quality alfalfa hay contain enough fiber? This is a more complicated question as it depends on how much total hay the horse is eating. For example, if you have an easy keeping horse (1000 lbs.) that is being limit fed alfalfa less than 15 pounds of hay per day, it is certainly possible for this horse to be fiber deficient. Horses are good about letting their owners know they are fiber deficient since they will seek other sources of fiber. Unfortunately, their alternative fiber sources often include wood fence materials, stall fronts or trees. On the other hand, if you are feeding alfalfa hay free choice (greater than 25 punds of hay per day) this horse will typically be getting enough fiber in the diet and will not seek out alternative fiber sources.
