Fatty acid profile and oxidative stability of milk from Holstein cows fed with extruded soybean and organic selenium

The objective of this work was to evaluate the effect of extruded soybean and organic selenium supplementation on fatty acid profile and oxidative stability of Holstein milk. Twenty-four Holstein cows were distributed in three blocks and were allocated in three treatments: control diet; diet with 21% extruded soybean; and diet with 21% of extruded soybean + 5 mg of organic selenium. The experiment lasted six weeks. The cows fed with extruded soybean diet produced milk with lower concentration of short and medium chain fatty acids and higher concentration of long chain fatty acids, lower concentration of saturated fatty acids and higher concentration of polyunsaturated fatty acids and conjugated linoleic acid content. The organic selenium supplementation increased milk selenium concentration and delayed milk oxidation. Diet with 21% extruded soybean modified fatty acid profile and resulted in milk susceptible to oxidation. Organic selenium supplementation reduced oxidation and influenced positively the stability of milk.