Alfalfa is a nutritious forage that can benefit many classes of horses, including those with elevated energy, protein, or vitamin and mineral requirements.Due to its high energy, protein, and calcium content, alfalfa must be carefully added to the diet to avoid dietary imbalances.    
                                                   
GROWING HORSES
Growing horses require a carefully balanced diet to support healthy development. Alfalfa is a good forage source to meet young horses' digestible energy and protein needs. However, feeding alfalfa hay on its own may provide too much digestible energy, leading to a fast growth rate and increasing the risk of developmental orthopedic disease. Since alfalfa is quite high in calcium relative to phosphorus, it must be added to the diet in an appropriate balance to avoid a high calcium-to-phosphorus ratio, which can impact growth and bone development.

LACTATING HORSES
Mares in the early stages of lactation have some of the highest energy and protein requirements of any class of horse. It is important to feed lactating mares an adequate diet to ensure they produce enough good quality milk to support the health of their growing foal.Alfalfa hay is a particularly good option for lactating mares because it is nutrient-dense. Additionally, the higher voluntary intake compared to other hays makes it a good option if a mare's appetite is limiting her intake.   
                                        
HORSES WITH ULCERS                                                                                   
Because of its high protein and calcium content, alfalfa is effective at buffering stomach acid. This can help increase the stomach's pH and reduce the risk of gastric ulcers.Gastric ulcers occur when stomach acid causes painful lesions or sores to form on the lining of the horse's stomach. Ulcers are particularly prevalent in performance horses, affecting up to 100% of Thoroughbred racehorses.                 
Feeding alfalfa may also decrease the secretion of gastric acid from stomach cells. Research in rats shows that a high-calcium diet inhibits the production of stomach acid, resulting in a higher pH.                                                                                 
Researchers have found that diets containing alfalfa hay significantly decreased the number and severity of gastric lesions in horses. Additionally, alfalfa can be a good option to meet caloric needs while avoiding excessive concentrate intake. Grain-based feeds can exacerbate ulcers due to high non-structural carbohydrate (NSC) content. 

                                                                                                   
Performance horses                                                                                   
Horses in moderate to heavy work have higher energy and protein needs than those at maintenance. Alfalfa can be used as a portion of the forage supply to meet these needs. alfalfa can also benefit exercising horses at higher risk of gastric ulcers by helping buffer gastric acids. Keep these considerations in mind when adding alfalfa hay to the horse diet.   
          
• Heat production: Protein generates more heat during digestion than fat. The high protein content of alfalfa may impact performance by increasing body temperature. Hydration status: Excess protein consumption increases the need to eliminate nitrogen via urine which removes water from the body and can impact hydration during exercise. Electrolyte balance: The high calcium content can disrupt electrolyte balance during and after exercise.

These factors have less of an impact on horses performing short bursts of intense exercise (i.e. racehorses) and are more of an issue for horses performing prolonged exercise (i.e. endurance racing).It is generally not recommended to feed a high level of alfalfa (more than 30% of forage) to endurance horses