Abstract
The aim of this study is compare the use of alternative methods (purine bases and odd-chain fatty acid AGCI) to 15N, as microbial markers to quantify the flow and microbial protein synthesis (PMic) in Nellore cattle feedlot, receiving high grain diets with different levels and sources of protein. Five Nellore cattle cannulated in rumen and duodenum (average body weight 360 kg and average…