When isoleucine and valine started becoming commercially feasible, researchers considered whether those compounds might enable an increase in the maximum dietary synthetic lysine level in later diets.

In experiments with five different diets, researchers reproduced the synthetic lysine maximum using four amino acids, then attempted to correct using six amino acids.

Unfortunately, the research did not show that branch chain amino acids could support an increase in L-HCl max. At some point, something other than amino acids appears to be first-limiting.

However, the team did find that there was an opportunity during the early growth phase (65 to 105 pounds) to use more than 10 pounds of synthetic lysine, which would improve overall performance.