title: Chemical composition of yak colostrum and transient milk.
abstract: The objective of this study was to assess the changes in the chemical composition of yak colostrum and transient milk. Samples were collected from 12 yaks on days 1, 2, 3, 4, 5, 6 and 7 post-partum (PP). The gross composition, nitrogen fraction distribution, amino acid (AA) profile and fatty acid (FA) profile were analysed. All the components decreased rapidly during the first 3 days except lactose which increased. The ratio of whey protein to casein protein decreased from 46:54 to 17:83 during the first 7 days PP. The content of all the AAs decreased, while the percentages of eight essential AAs in protein of samples increased during the study period. Monounsaturated FAs and polyunsaturated FAs decreased in the first 7 days PP, whereas saturated FAs increased. In conclusion, the changes in chemical composition were remarkable during the first 3 days. The slight variations, happened during the transient period, are not negligible, which also should be taken into account in the development of yak colostrum supplements.
authors.affiliation: College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China.
authors.forename: N
authors.initials: N
authors.lastname: Cui
authors.affiliation: College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China.
authors.forename: P C
authors.initials: PC
authors.lastname: Wen
authors.affiliation: College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Liang
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, China.
authors.forename: H N
authors.initials: HN
authors.lastname: Liu
authors.affiliation: College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China.
authors.forename: W B
authors.initials: WB
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.
authors.forename: P J
authors.initials: PJ
authors.lastname: Wang
authors.affiliation: Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.|Beijing key laboratory of Nutrition, Health & Food Safety, Beijing, China.
authors.forename: H Y
authors.initials: HY
authors.lastname: Guo
authors.affiliation: College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China.|Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.
authors.forename: F Z
authors.initials: FZ
authors.lastname: Ren
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D002417:Cattle; D003126:Colostrum / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry; D005260:Female; D008892:Milk / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D011247:Pregnancy
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D009584:Nitrogen
keywords: amino acid; colostrum; fatty acid; gross composition; nitrogen fraction; yak