Barium selenate supplementation and its effect on intramammary infection in pasture-based dairy cows

Abstract

A significant proportion of cattle receive inadequate dietary Se because of its low content in soils and pastures of various regions of the world. Several economically important diseases in dairy cows, such as mastitis, have been associated with Se deficiency. The objective of this study was to evaluate the effect of a single injection of a long-acting form of Se at drying off on the risk and incidence rate of new intramammary infections and on milk somatic cell count in the subsequent lactation in pasture-based dairy cows. Forty-nine Chilean Holstein-Friesian cows were fed a diet containing <0.05 mg of Se/kg of ration dry matter. During the dry period, cows were allocated to 1 of 2 groups, a supplemented (n=24) group treated with a single subcutaneous injection of barium selenate 2 mo before calving and a control group (n=25) that remained unsupplemented. Duplicate foremilk samples were aseptically collected within 6 d after calving and every 2 wk until drying-off for bacteriological culture. Milk samples were also collected monthly for somatic cell count evaluation. Blood samples were collected before treatment and at 30, 90, 180, and 270 d after treatment for analysis of blood glutathione peroxidase (GPx) activity. The activity of glutathione peroxidase was higher in supplemented cows 30 d after the injection until the end of the study. The risk and incidence rate of new intramammary infections was not affected by supplementation. A progressive increase in somatic cell count was observed throughout lactation, but there was no effect of supplementation. In conclusion, a one-time injection of barium selenate 2 mo before calving in these pasture-based dairy cows did not affect udder health in the subsequent lactation, indicating that Se basal intake was adequate for preventing subclinical mastitis in pasture-based cows in southern Chile.

The Efficacy of a Long-Acting Injectable Selenium Preparation Administered to Pregnant Ewes and Lambs

“…According to Pehrson et al [27], Se is not effectively transferred to milk; therefore, it does not guarantee healthy Se status in the offspring. In the present study, Se supplementation during pregnancy tended to increase the Se content of milk, and similar observations were made by other authors [28][29][30][31].…”

Selenium-Dependent Regulation of Oxidative Stress and Immunity in Periparturient Dairy Cattle

“…More recent studies confirmed that higher bulk tank Se concentrations were associated with a lower risk of being a Staphylococcus aureus -positive herd [45]. Moreover, Se supplementation of pastured dairy heifers and cows before calving reduced the prevalence of new intramammary infections and high SCC during early lactation [46, 47]. Se nutritional status is important to many reproductive functions of dairy cattle as well.…”

A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species—A Critical Review

“…The administration of selenium to heifers and cows before calving reduced the prevalence of intramammary infections and high somatic cell count (SCC) during early lactation [ 242 , 243 ]. Injection application of Se together with Zn, Mn and Cu had a positive impact on reductions of somatic cell scores (SCSs) and mastitis incidences [ 244 ].…”