Various problems are associated with a disproportionate amount of AA in diet. Symptoms for both deficiency and toxicity of individual AA are well established. Precipitating a simple AA deficiency or toxicity in modern production system is quite difficult. However, you need to worry about the interaction among amino acids. Amino acid antagonism such as lysine-arginine and branched chain AA antagonism is more difficult to detect.
Ruminant has no amino acid requirement.
Instead, they have a nitrogen requirement. Ruminants break down dietary protein into ammonia and carbon skeleton by rumen microbes, and synthesize their own microbial protein. A readily available carbohydrate source to provide the carbon skeleton for protein synthesis is critical. Otherwise, the toxic ammonia builds up quickly in the rumen. Constant turnovers of proteins in the body and the loss of proteins, mainly in feces, are the basis for protein requirement.