Shengbo Yu¹, Zhishen Mu¹, Xuena Dong², Zengli Gao², Guozhi Ji², Yu Liu^1,, Yun Chen^1,

A total of 124 individual yak milk samples and 400 individual Holstein cow milk samples were collected from Tibet Autonomous Region and Inner Mongolia Autonomous Region, China. In order to better understand the difference between yak and Holstein cow milk. The composition of two milks, protein composition, β-casein gene sequence, amino acid composition, fatty acid composition and other parameters were analyzed and compared by using techniques such as capillary electrophoresis, gene sequence sequencing, amino acid analysis and gas chromatography. Yak milk has a higher total solids content than Holstein cow milk (18.99 g/100g and 12.44 g/100g). The casein composition of yak milk is suitable for the nutritional needs of infants. The proportion of β-Lactoglobulin content in yak milk whey protein is significantly higher than that in Holstein cow milk and all β-casein in yak milk is A2β-casein. Yak milk contains more amino acids and essential amino acids than Holstein cow milk, especially for phenylalanine (0.267 g/100g) and leucine (0.747 g/100g). Yak milk has higher n-3 and n-6 unsaturated fatty acids, especially for DHA (1.848 mg/100g) and EPA (3.542 mg/100g), which are not found in Holstein cow milk. So far, little attention has been paid to the role of yak milk. This paper will provide data to support subsequent studies.

yak milk, A2β-casein, DNA sequencing, yak milk amino acid, yak milk fatty acid