The term “bioavailable” is often used to describe the nutritional content of hay, but what does it mean? According to the Merck Manual, “Bioavailability refers to the extent to and rate at which the active moiety [i.e. vitamin, mineral, supplement] enters systemic circulation [the blood stream], thereby accessing the site of action.” Simply put, bioavailability has to do with how much of a specific nutrient the animal actually gets from consuming a substance. With most supplements, only a small percentage of the nutrient can be used by the animal when ingested. An animal fed Alfalfa or Timothy with bioavailable nutrients however, is able to absorb a high percentage of the nutrients.
For instance, Alfalfa hay contains a high amount of bioavailable calcium. This means that the animal who is consuming the Alfalfa is absorbing most of the calcium contained in the hay. Calcium supplements, most of which are derived from Limestone flour, have an inorganic form of calcium that is not easily absorbed into the animal’s system. Calcium is an important component of a horse’s nutrition as it contributes to the skeletal integrity. It is particularly important for breeding mares and young horses. Research has also shown that a diet of calcium rich Alfalfa improved the hoof growth. Considering calcium's impact on such important aspects of horse health, being sure the horse is receiving the right amount of Calcium is vital. Alfalfa’s bioavailable nutrients are important to animal health because they are organic and easily absorbed ensuring the animal is provided the best nutrition.
Finding a bioavailable source of nutrition for animals is essential to a feed program. Adding substances with low bioavailability increases cost while providing little benefit to the animal. In addition, it is difficult to provide a balanced diet without knowing how much of a non-Bioavailable mineral the animal is actually absorbing. With the wide range of bioavailable vitamins and minerals contained in Alfalfa, coupled with its superior protein content, Alfalfa provides a high feed value and reliable source of nutrition.