[Potential involvement of selenium in the occurrence of milk fever in cattle]

Frequent occurrence of parturient paresis (milk fever [MF]) and a partly unsatisfactory treatment success raises the question as to whether in addition to the known causes, other factors influence the incidence and success of MF treatment. Trace elements, including selenium (Se), are involved in bone metabolism, however, there is little knowledge regarding the influence of Se on MF development. The aim of this study was to analyse the concentrations of Se and the statistical relationships to parameters associated with Se influence in downer cows.

A total of 195 Simmental cows, downer cows and clinically healthy control animals were divided into five groups: a) control group (CG, n = 21), b) all cows with MF (n = 174), c) MF cows without additional diseases (n = 145), d) cows with MF and mastitis (n = 10) and e) cows with MF and retained placenta or endometritis (n = 19). Se, calcium (Ca), inorganic phosphate (Pi), tumour necrosis factor α (TNFα), haptoglobin (Hp), antioxidants (Trolox Equivalent Antioxidative Capacity: TEAC) and further metabolic parameters were analysed in the blood serum.

The serum concentrations of Se, Ca, Pi and TEAC were lower in groups b) to e), whereas Hp was higher than in the CG (p ≤ 0.05). Se was positively correlated with Pi in the CG, in groups b) and c) with Ca, Pi, K and Mg and in group c) with Hp (p ≤ 0.05). Both Ca and Pi were significantly lower in group c) compared to group d) (p ≤ 0.05). TNFα was increased in groups b) and c) compared to group a) and correlated with Se in group e) (p ≤ 0.05). Alkaline phosphatase activity in groups b) and e) was lower than in the CG and correlated with Se in the CG and group b) (p ≤ 0.05).

These results, in agreement with the literature data, support the hypothesis that Se could be directly involved in bone metabolism and therefore in the pathogenesis of MF. Se acts via cytokines on Ca mobilization from bone. The concentrations of Hp and TEAC support this interpretation. Therefore, control of the Se status and Se supplementation of cows should be included in the prevention and advanced therapy of MF.