Oxidative Stability of Flaxseed (Linum usitatissimum L.) Cake and its Inclusion in the Diet of Lactating Cows

Abstract The objective was to evaluate the oxidative stability of flaxseed cake and its inclusion in the diet of lactating cows, on milk production and composition and blood parameters (total cholesterol, triglycerides, high density lipoprotein -HDL and low density lipoprotein - LDL). Oxidative stability was evaluated by acidity index (AI) and peroxides (PI), determined from day zero to the ninth day of storage. Eighteen crossbreed Holstein x Jersey cows were used, nine animals per treatment (without and with the inclusion of cake). The experimental design was completely randomized, with two treatments and nine replications. There was an increase in PI during the first six days of storage, followed by a decrease on the ninth day. Supplying 4.5% flaxseed cake to lactating cows for 90 days did not promote changes in production, chemical composition and fatty acid profile of milk, somatic cell counts and blood parameters. Thus, flaxseed cake can be used to feed lactating cows.