Influence of parities and the number of days on active ingredients of yak colostrum

Double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was used to detect test samples. This essay mainly discussed the concentration variation of immunoglobulin G (IgG) , lactoferrin (LF) and insulin-like growth factor-I (IGF-I) in five different parities from Tianzhu white yak’s colostrum during the lactation of seven days. It will be a theoretical basis to study the nutritional value as well as rational development and utilization of white yak’s colostrum. The results showed that the highest concentration point of IgG, LF and IGF-I in yak’s colostrums was the birth of the fourth parities on the first day, the numbers respectively reached 2404. 41, 2001. 53and 1206. 48U/L. Besides, the number had a sharp decline with the process of lactation and gradually get a moderation four days later. The study showed that the concentration of colostrum IgG, LF and IGF-I can keep higher during the first four days, namely, it had a richful nutrition, which was a good reason for us to research.