Building global models for fat and total protein content in raw milk based on historical spectroscopic data in the visible and short-wave near infrared range

•PLS models for fat and protein content determination were built on historical data.•Seasonal and geographical factors have strong effect on the milk nutrient composition and spectral features.•Interval selection method is useful for the calibration performance for both studied nutrients.•Feasibility of model transfer by “slop and bias correction” was proved.