Abstract:

【Objective】The objective of the study is to investigate the changes of the milk protein with low somatic cell counts, medium somatic cell counts, high somatic cell counts and clinical mastitis.【Method】Milk proteins were examined using an integrated proteomic approaches consisting of protein separation by two-dimensional gel electrophoresis, stained with Coomassie Blue G-250 solution, and protein identification by HPLC coupled with tandem ion trap spectrometry.【Result】Albumin and caseins variant were increased in milk with medium somatic cell counts, high somatic cell counts and clinical mastitis comparated with low somatic cell counts. An abundant caseins (α-, β- and κ-caseins) were degraded, while low abundant protein serum albumin, transferrin, fibrinogen beta chain, and haptoglobin could be identified in clinical mastitic milk.【Conclusion】Results suggested that caseins were degraded in milk with medium somatic cell counts, and significantly increased in high somatic cell counts, and abruptly increased in clinical mastitis. The findings may provide a survey of milk protein modulation and increase the knowledge of proteomic profile of milk protein changes with low somatic cell counts, medium somatic cell counts, high somatic cell counts and clinical mastitis to improve the technological quality of milk.