The objectives of this thesis were to 1) evaluate the impact of supplementing omega-3 (n3) fatty acids (FA) using calcium salts enriched in fish oil (Ca-FO) in the early postpartum period on the degree and resolution of inflammation using an induced acute inflammation model, and 2) test whether these effects were from the increased energy density of the diet or the impacts of n3 FA on immune cell biology. Supplementing Ca-FO resulted in changes to the composition of plasma, milk, and peripheral blood leukocytes. Increased basal and endotoxin-induced concentrations of IFNγ and MIP1ɑ, attenuated febrile responses to the endotoxin challenge, and greater rumen activity one day after endotoxin-induced inflammation suggest that supplementation with n3 FA can alter postpartum inflammation.