I want to see the effects of Non-SBM diet on feather growth and compare it with SBM diet on slow growing broilers.

Remarkably, feather growth or development is different than the feather damage, there is feather damage scoring system developed by RSPCA and WUR but,

I'm looking for a numeric scoring system (such as 0. Not developed 1. poorly developed 2. enough developed 3. fully developed) to use it as reference, does such soring system exist, if so, please refer me to, I will appreciate your cooperation.