The effects of pasture grazing on milk quality

How does grazing affect milk quality and fatty acid (FA) composition? Grazing animals can select, prefer green leaves and have fresh herbage diets rich in poly-unsaturated fatty acids (PUFA). The environment and farm management affect herbage allowance and grazing time. Milk from grazing-based production systems contains less saturated FA and more n-3 PUFA than with indoor feeding. The occurrence of natural trans-11 FA in milk predominates with grazing, whereas intensive feeding practices enhance trans-10 FA with possible negative health effects. Concentrates and starch-rich fodders affect rumen retention time and alter rumen biohydrogenation pathways. As some forbs reduce biohydrogenation, grassland species diversity may improve PUFA transfer efficiency from feed to milk. Trends in animal genetics and increased herd size, TMR feeding and automated milking systems cause reduction of grazing in Europe, which can increase saturated and trans-10 milk FA concentrations and reduce naturally occurring fat-soluble vitamins and antioxidants in dairy products.