The effects of different conserved forages on milk fatty acid and terpene composition in Alpine dairy production.

Farming systems in mountainous areas are generally based on local forage resources and the milk produced is transformed to typical and/or Protected Denomination of Origin (PDO) high quality cheeses. Most of the milk is produced when animal diets are based on conserved forages, locally produced or purchased from the plain, which can also have an influence on the beneficial health fatty acid (FA) contained in milk fat. The aim of this study was to compare the effects of different winter cow diets based on local and non-local forage resources on milk FA composition in a mountainous area. Forty-five Aosta Red Pied cows were fairly allocated into three groups and fed different diets based on local hay (LH), local haylage (LS), and hay purchased from the plain (LOH), respectively. Diets were supplemented with concentrate to balance for energy, protein, and minerals cow requirements. The high forage proportion of diets allowed to obtain milk with a relatively healthier FA profile, with good contents of conjugated linoleic acid (CLA) and unsaturated FA. Furthermore, the LS-based diet did not lead to any change of the milk FA profile compared to LH, thus allowing a better self-sufficiency of mountainous dairy farms.