Watch Out: How horse feed to increase muscle mass Is Taking Over and What to Do About It

https://sites.google.com/view/aminoacid-supplement-for-horse/

Endurance horses log serious miles on engine and topline, and Pur.Muskel backs both with 14.1 MJ/kg of digestible energy and 20% raw protein. Mix it into a complete ration at 80–100 g per 220 lb of body weight for heavy work.