Abstract: This experiment was conducted to study the effects of the proportion of Lys and Met (Lys/Met) with 18% protein level on development of complex stomach in early-weaned Tibetan lambs. A total of 42 early-weaned Tibetan lambs with (55±2) days and (10.85±0.65) kg were randomly allocated into 3 groups with 14 lambs(half males and half females) in each group, early-weaned Tibetan lambs in each group were fed basal diets which Lys/Met was different, the experiment lasted for 20 days. The measured indicators included the weight and morphology of stomach. The results showed as follows, when the Lys/Met was 3.1∶1, the gain of rumen and complex stomach development was best, growth of rumen and reticulum papillae, thickening of stratum corneum, mucosa epithelium, central muscularis in omasum and thickening of mucosa in fundic gland of abomasums were the best. It was concluded that the nutrition levels of diets could influence the growth and development of complex stomach, the suitable ratio of Lys/Met could efficiently promote the growth and development of complex stomach, 3.1∶1 of the ratio Lys/Met was the best ratio under the 18% protein level.

Key words: nutrition level; Tibetan lambs; early-weaned; stomach weigh; morphology of stomach