关键词: 放牧强度, 补饲水平, 羊肉, 氨基酸, 脂肪酸

Abstract: To investigate the differences in amino acid and fatty acid composition of lamb meat under different grazing intensity and supplementary feeding level,seventy-two 3-month-old male Hulunbuir lambs were selected from the Inner Mongolia,and a two-factor (grazing intensity and supplementary feeding level) randomized block design was used. The grazing intensity included moderate grazing (MG) and heavy grazing (HG);supplementary feeding level included no supplementation (NS),1% body weight supplementation (S1) and 2% body weight supplementation (S2),a total of 6 treatments. The results showed that the intramuscular fat (IMF) content of MG lambs was significantly higher than HG;the IMF and protein contents of S2 lambs were significantly higher than NS. The total amino acid contents of HG and S2 lambs were significantly higher than those of MG and NS. Compared to NS,S2 lamb decreased by 17.14% and 20.59% in docosanoic acid and tricosanoic acid contents,respectively,and increased by 30.91% and 21.97% in t10,c12-conjugated linoleic acid and total unsaturated fatty acid contents,respectively,with an n6/n3 ratio of less than five. In summary,the feeding regimes of moderate grazing combined with supplementary feeding is conducive to the production of lamb meat with high-quality protein and fatty acid composition,as well as to the sustainable development of grassland.

Key words: Grazing intensity, Supplementary level, Lamb meat, Amino acid, Fatty acid