Multivariate Modelling of Milk Fatty Acid Profile to Discriminate the Forages in Dairy Cows' Ration

Abstract

Although there are many studies on the importance of fatty acids (FA) in our diet and on the influence of cows’ diet on FA metabolism, only a few investigate their predictive capacity to discriminate the type, amount and conservation method of the dietary forages. This research quantitatifies differences in FA concentrations and, using a supervised factorial discriminant analysis (FDA), assesses which could be biomarkers when replacing maize silage with other silages, grass/lucerne hays or fresh grass. The statistical modelling identified three main clusters in milk FA profiles associated with silages, hays and fresh grass as dominant roughages. The main implication of a dairy cow feeding system based on poliphytic forages from permanent meadows is to enhance milk’s nutritional value thanks to an increase in beneficial FA belonging to omenga-3 polyunsaturated FA, conjugated linoleic acids and odd chain FA, compared to the use of maize silage from arable land. The study also identified a small but powerful and reliable pool of FA that can act as biomarkers to authenticate feeding systems: C16:1, C17:0, C18:0, C18:3n-3, C18:1 c-9, C18:1 t-11, C20:0.