Organic selenium supplementation improves growth parameters, immune and antioxidant status of newly received beef cattle

The effects of dietary supplementation with selenium enriched yeast on growth, immune and antioxidant status were assessed on 228 newly received beef cattle. During the adaptation phase (54 days), the animals were housed in 38 pens (19 pens per treatment) and supplemented with 0.32 mg · kg−1 DM of Se as sodium selenite (CTR) or selenium enriched yeast (SeY). At days 0, 19 and 54 the animals were weighed and blood samples were collected from one healthy animal per pen. During the experimental trial, bovine respiratory disease (BRD) occurrence was monitored. Blood antioxidant status, selenium serum concentration, bovine herpesvirus-1 (BHV-1) antibody titer and serum bactericidal activity were determined. Growth performance was improved (P < 0.05) and BRD occurrence was reduced (P = 0.06) in SeY group. SeY supplementation increased BHV-1 antibody titre after vaccination, highlighting a positive impact of SeY supplementation on immune system functioning. SeY supplementation improved (P < 0.01) selenium serum concentration and positively affected antioxidant status, expressed as Kit Radicaux Libres value, that tended to be higher (P = 0.07) in SeY group, due to Se higher bioavailability. The obtained results suggest that dietary supplementation with organic form of selenium improves growth performance, immune and antioxidant status in newly received beef cattle.