Dietary selenium effects on milk eicosanoid concentration in dairy cows during coliform mastitis

Abstract The effect of selenium deficiency on the product profile of arachidonic acid oxidation by enzymatic pathways in Holstein cows with experimentally-induced coliform mastitis was investigated. The animals were fed dairy rations containing 0.05 mg Se/kg dry matter, with the supplemented group receiving additional Se to increase the dietary concentration to approximately 0.35 mg Se/kg dry matter. Cows were inoculated intracisternally with 30 colony-forming-units of Escherichia coli at 14–16 weeks of lactation. Eicosanoids and bacteria numbers were recorded at various intervals of time for 60 h postinoculation. Milk from cows fed the Se-depleted diet had significantly higher (p 2 between 24 and 48 h and 6-keto-PGF 1α between 24 and 60 h postinoculation. Milk PGE 2 concentration was significantly higher in the Se-deficient group at 24 h, whereas LTB 4 was higher between 36 and 60 h postinoculation in the Se-deficient cows (p E. coli infection. The changes in eicosanoid concentrations may be associated with the altered pathogenesis and outcome of mastitis in a Se-deficient state.