Abstract: Eight female Small-tail Han×Polled Dorset lambs, with the average body weight of(8.90±0.38)kg, were fitted with the abomasum canula at the age of 40 days, and fed with diets 1, 2 and 3 during 60 to 80,81 to 120 and 121 to 240 days old respectively,and were supplemented with lysine at the dose of 1.2%,0.8% and 0.4% in diets 1, 2 and 3 respectively, to study the effect of dietary lysine supplementation on the nutrients arriving at the abomasum. The results showed that compared with that of the control group, supplementing lysine to the lambs from 60 to 240 old-days, increased the average amounts of DM arriving at abomasum by 7.01%(P＞0.05),11.59%(P＜0.01) and 10.65%(P＜0.05) respectively, increased the average amounts of OM by 8.48%(P＞0.05),13.01%(P＜0.05) and 12.14%(P＜0.05) respectively,increased the average amounts of CP by 11.12%(P＞0.05),21.73%(P＜0.01) and 12.44%(P＜0.05) respectively,increased the average amounts of microbial protein arriving at abomasum by 13.46%(P＜0.05),26.85%(P＜0.01) and 15.08%(P＜0.05) respectively,increased the average amounts of the total amino acids by 39.22%(P＜0.01),35.52%(P＜0.01) and 28.27%(P＜0.05) respectively,increased the average amounts of the total essential amino acids by 49.21%(P＜0.01),34.40%(P＜0.01) and 28.11%(P＜0.05) respectively,increased lysine by 43.77%(P＜0.01),37.25%(P＜0.01) and 34.38%(P＜0.05) respectively .The lysine arriving at abomasum mainly was combinative lysine both in the experimental and control groups, with less 1% of free lysine. Compared with the control group, by supplementing lysine to the lambs, the average amounts of voluntary intake of DM was increased by 12.57%(P＞0.05),19.38%(P＜0.01) and 16.29%(P＜0.01) respectively, the digested DM in forestomach was increased by 20.81%(P＞0.05),35.64%(P＜0.01) and 19.97%(P＜0.01) respectively,and the daily body weight gain was increased by 17.34%(P＜0.05), 21.30 %(P＜0.01) and 17.76%(P＜0.05) respectively. It was concluded that supplementing lysine to the 60 to 240 day’s lambs could increase the nutrients arriving at abomasum and the digested OM in forestomach, and as a result, increase the supplement of the nutrients to the lamb.

Key words: lysine; lamb; abomasum; nutrition