AOAC. 1990. Official methods of analysis 15th ed Association of Official Analytical Chemists. Washington, DC, USA:
Broderick GA, Wallace RJ. 1988. Effects of dietary nitrogen source on concentrations of ammonia, free amino acids and fluorescamine-reactive peptides in the sheep rumen. J Anim Sci 66:2233–2238.
Chen G, Sniffen CJ, Russell JB. 1987a. Concentration and estimated flow of peptides from the rumen of dairy cattle: Effects of protein quantity, protein solubility, and feeding frequency. J Dairy Sci 70:983–992.
Chen G, Russell JB, Sniffen CJ. 1987b. A procedure for measuring peptides in rumen fluid and evidence that peptide uptake can be a rate-limiting step in ruminal protein degradation. J Dairy Sci 70:1211–1219.
Choi CW. 2002. Assessment of the flow of soluble dietary non-ammonia nitrogen escaping degradation in the rumen of dairy cows fed grass silage based diets. Doctoral dissertation. University of Helsinki. Department of Animal Science; Viikki. Finland:
Choi CW. 2007. Diurnal patterns in the flow of escapable soluble non-ammonia nitrogen fractions in omasal digesta as influenced by barley and rapeseed meal supplementation in cows fed grass silage based diet. J Anim Sci Technol 49:341–350.
Choi CW, Choi CB. 2003. Flow of soluble non-ammonia nitrogen in the liquid phase of digesta entering the omasum of dairy cows given grass silage based diets. Asian-Aust J Anim Sci 16:1460–1468.
Choi CW, Ahvenjärvi S, Vanhatalo A, Toivonen V, Huhtanen P. 2002a. Quantitation of the flow of soluble non-ammonia nitrogen entering the omasal canal of dairy cows fed grass silage based diets. Anim Feed Sci Technol 96:203–220.
Choi CW, Vanhatalo A, Ahvenjärvi S, Huhtanen P. 2002b. Effects of several protein supplements on flow of soluble non-ammonia nitrogen from the forestomach and milk production in dairy cows. Anim Feed Sci Technol 102:15–33.
Choi CW, Vanhatalo A, Huhtanen P. 2002c. Concentration and estimated flow of soluble non-ammonia nitrogen entering the omasum of dairy cows as influenced by different protein supplements. Agric Food Sci Finl 11:79–91.
Huhtanen P, Brotz PG, Satter LD. 1997. Omasal sampling technique for assessing fermentative digestion in the forestomach of dairy cows. J Anim Sci 75:1380–1392.
Kim JH, Oh YK, Kim KH, Choi CW, Hong SK, Seol YJ, Kim DH, Ahn GC, Song MK, Park KK. 2009. Effects of protein supply from soyhulls and wheat bran on ruminal metabolism, nutrient digestion and ruminal and omasal concentrations of soluble non-ammonia nitrogen of steers. Asian-Aust J Anim Sci 22:1267–1278.
Madsen J, Hvelplund T, Weisbjerg MR, Bertilsson J, Olsson I, Spörndly R, Harstad OM, Volden H, Tuori M, Varvikko T, Huhtanen P, Olafsson BL. 1995. The AAT/PBV protein evaluation system for ruminants. A revision. Norw J Agric Sci Suppl19:1–37.
Nolan JV. 1993. Nitrogen kinetics. Quantitative aspects of ruminant digestion and metabolism. Forbes JM, France J, editorsCAB International Wallingford; Oxon, UK: p. 123–143.
Oh YK, Kim JH, Kim KH, Choi CW, Kang SW, Nam IS, Kim DH, Song MK, Kim CW, Park KK. 2008. Effects of level and degradability of dietary protein on ruminal fermentation and concentrations of soluble non-ammonia nitrogen ruminal and omasal digesta of Hanwoo steers. Asian-Aust J Anim Sci 21:392–403.
Ørskov ER, McDonald P. 1979. The estimation of protein degradability in the rumen from incubation measurements weighted according to rate passage. J Agric Sci (Camb) 92:499–503.
Richards CJ, Branco AF, Bohnert DW, Huntington GB, Macari M, Harmon DL. 2002. Intestinal starch disappearance in steers abomasally infused with starch and protein. J Anim Sci 80:3361–3368.
Richards CJ, Swanson KC, Paton SJ, Harmon DL, Huntington GB. 2003. Pancreatic exocrine secretion in steers infused postruminally with casein and cornstarch. J Anim Sci 81:1051–1056.
Robinson PH, McQueen RE. 1994. Influence of supplemental protein source and feeding frequency on rumen fermentation and performance in dairy cows. J Dairy Sci 77:1340–1353.
Robinson PH, Veira DM, Ivan M. 1998. Influence of supplemental protein quality on rumen fermentation, rumen microbial yield, forestomach digestion, and intestinal amino acid flow in late lactation Holstein cows. Can J Anim Sci 78:95–105.
SAS. 2002. Statistical analysis systems. User’s guide: Statistics. Version 9.1 Edition2002. SAS Inst, Inc; Cary, NC, USA:
Smith SB, Crouse JD. 1984. Relative contributions of acetate, lactate and glucose to lipogenesis in bovine intramuscular and subcutaneous adipose tissue. J Nutr 114:792–800.
Swanson KC, Richards CJ, Harmon DL. 2002. Influence of abomasal infusion of glucose or partially hydrolyzed starch on pancreatic exocrine secretion in beef steers. J Anim Sci 80:1112–1116.
Taniguchi K, Huntington GB, Glenn BP. 1995. Net nutrient flux by visceral tissues of beef steers given abomasal and ruminal infusions of casein and starch. J Anim Sci 73:236–249.
Van Straalen WM, Tamminga S. 1990. Protein degradation of ruminant diets. Feedstuff evaluation 1 Livestock Feedingstuffs Composition. Wiseman J, Cole DJA, editorsButterworths; London, UK: p. 55–72.
Volden H, Harstad OM. 1995. Effect of rumen incubation on the true indigestibility of feed protein in the digestive tract determined by nylon bag techniques. Acta Agric Scand, Sect A, Animal Sci 45:106–115.
Wright DE, Hungate RE. 1967. Amino acid concentration in rumen fluid. Appl Environ Microbiol 15:148–151.