Variations in Fatty Acids, Micronutrients and Metabolites in Discrete Milk Lines of Danish Dairy Milk

Highlighting factors driving natural variation in milk composition among different dairy milk lines is important not only to secure uniform products but also for possible exploitation of the inherent variation. The composition of milk is related to genetic and environmental differences, causing variation in the milk delivered to the dairies. This study investigated compositional variations related to management systems, feeding strategies and seasonal periods. Milk samples from 15 Danish dairies, representing 34 unique milk lines, were collected monthly for two years. The study revealed significant compositional differences in fatty acids, micronutrients and metabolites relative to management systems. This is possibly related to differences in feeding and management practices, e.g., periods of outdoor grazing. Data expressed a higher degree of variation in milk samples representing biodynamic and organic milk lines with extensive grass feeding in comparison with conventional and organic milk lines reflecting more common Danish feeding practices.