Summary and Implications
The National Academies of Sciences, Engineering and Medicine - Nutrient Requirements of Beef Cattle (NASEM), formally referred to as the National Research Council (NRC), has long been the standard of formulation for beef cattle rations. However, the changes presented in the 8thEdition (2016) regarding the empirical method of formulation appear to only work well with cows and more mature stocker cattle consuming medium- to high-quality forage (51.5-64% TDN) when the microbial efficiency of converting diet TDN to microbial protein are adjusted from the current recommendation back to previously published efficiencies.
Dahlke, Garland; Gunn, Patrick; and Loy, Dan
"Adapting the 2016 National Academies of Sciences, Engineering and Medicine—Nutrient Requirements of Beef Cattle to BRaNDS Software—Considering Metabolizable Protein,"
Animal Industry Report:
AS 663, ASL R3133.
Available at: http://lib.dr.iastate.edu/ans_air/vol663/iss1/6