Bulk tank milk selenium concentration in dairy herds from Southern Chile and its relationship to productive performance

Abstract

An observational study was conducted in 59 Chilean dairy farms to evaluate bulk tank milk selenium (Se) concentration, and its association with measures of milk production parameters and udder health, measured as bulk tank somatic cell count. Fifty-nine dairy herds from Southern Chile were selected. Bulk tank milk samples were collected four times (Spring 2007 and Summer, Autumn and Winter 2008). A survey about general and nutritional management of the herds was conducted. Data on productive performance were also collected. Data were analyzed by using linear mixed models. Mean bulk tank milk Se concentration was 14.7 µg/L (SD: 6.5 µg/L), indicating a high variation among herds (44%). No association between bulk tank milk Se concentration and herd productive performance was observed. Nevertheless, 82% (n = 231) of bulk tank milk samples had a milk Se concentration lower than the reference of 20 µg/L. These results are indicating that bulk tank milk Se concentration in selected dairy herds from Southern Chile is lower than international reference values, reflecting an inadequate intake of Se. This inadequacy was not necessarily translated into low milk yield or low quality milk.