Abstract: Four male China merino(Xinjiang type) fitted with ruminal and duodenal cannulae were used in a 4×4 Latin square design trial to study the effect of supplemental Schiff’s base of lysine 3.42 g/d, 6.84 g/d(the content of lysine is 2 g and 4 g respectively) and L-lysine-HCL 2.56 g , 5.12 g/d(the content of lysine is 2 g and 4 g respectively) on the flow of protein and liquid free amino acids to the small intestine. The results indicated that 6.84 g/sheep/d Schiff’s base of lysine equal to 4 g free lysine increased flow of Lys, Glu and Tyr to the small intestine by 25.17%, 38.35% and 33.88%（P<0.05） respectively. Flows of other free amino acids to the small intestine were not affected by supplementing with Schiff's base of lysine. Supplementing Schiff’s base of lysine did not affect crude protein intake, microbial protein synthesis and flow of rumen undegradable protein to the small intestine. Therefore, supplementing Schiff’s base of lysine could increase the flow of free lysine to the small intestine of sheep and this depended on the dosage of Schiff’s base of lysine.

Key words: Schiff’s base of lysine; sheep; small intestine; free amino acid