Boucher, S. E., S. Calsamiglia, C. M. Parsons, H. H. Stein, M. D. Stern, P. S. Erickson, P. L. Utterback, and C. G. Schwab. 2009. Intestinal digestibility of amino acids in rumen undegraded protein estimated using a precision-fed rooster bioassay: II. Distillers dried grains with solubles and fish meal. J. Dairy Sci. 92:6056-6067. Link to full text (.pdf)