In the present study, 113 tank milk samples were collected from 30 farms located in the Netherlands and analyzed for their triacylglycerol (TAG) and cholesterol profiles. Significant differences in the TAG profile between winter and spring–early summer milk were observed. The differences between milk from cows on pasture and stabled cows collected in spring–early summer were less remarkable than those between spring–early summer and winter milk. Classification models based on partial least square discriminant analysis of the TAG profile were developed for the prediction of fresh grass feeding, pasture grazing and organic farming. Milk from cows that had fresh grass in the daily ration could be distinguished from milk from cows that had no fresh grass with sensitivity and specificity values >85 %. However, the specificity reduced to 72 % when the samples collected in spring–early summer were considered only. Authentication of pasture grazing and of organic/biodynamic farming based on TAG profile proved difficult during the grazing period.