2 

 injecting or placing the mineral inside the animal's body 

 (McDowell, 1992) . 



Mineral supplements originate from different sources, 

 with the most commonly used sources being inorganic in nature. 

 It is known that different forms of inorganic minerals may be 

 absorbed with varying efficiency. 



Organic minerals are those that have an organic molecule 

 (e.g., amino acid, carbohydrate, protein) attached to it . A 

 chelated mineral is a compound which contains the metal bound 

 to a synthetic molecule such as ethylenediaminetetraacetic 

 acid (EDTA) . These chelates are usually chemically stable and 

 water soluble; however, the ligand is not biodegradable and, 

 therefore, the mineral is not always bioavailable to the 

 animal even after it is absorbed. In contrast, a metal-amino 

 acid complex is the product resulting from complexing a 

 soluble metal salt with an amino acid. The ligand formed in 

 this complex is biodegradable and, therefore, the mineral may 

 be more bioavailable. 



Several products offering minerals in chelated form or 

 amino acid complexes are available for mineral 

 supplementation. Although considerable research has been done 

 concerning the performance benefits, there have been fewer 

 comparisons of minerals as amino acid complexes compared to 

 their inorganic counterparts. 



Some trials have determined ruminal degradation of 

 different amino acid complexed minerals. There is, however, 



