Evaluation of supplemental vitamin E on 56-day feedlot growth performance and plasma tocopherol concentrations in calf-fed Holstein steers

Abstract

Fifty-four Holstein steer calves, divided in two weight groupings (141.2 +/- 4.9 kg and 454.2 +/- 7.0 kg respectively), were used in a 56-day study to evaluate the influence of supplemental vitamin E on growth performance and plasma vitamin concentrations. Steers were assigned within body weight groupings to 18 pens, 3 steers/pen. Dietary treatments consisted of a steam-flaked corn-based growing-finishing diet supplemented to provide 0, 250, or 500 IU/d of vitamin E as all racemic a-tocopherol. No morbidity was apparent during the course of the study. Calves in the heavier weight grouping had greater average daily gain (24.4\%, P <.01), dry matter intake (54.3\%, P <.01), and lower gain efficiency (40.7\%, P <.01). Vitamin E supplementation did not affect (P >.10) feedlot growth performance. Initial and 56-day plasma tocopherol were not influenced (P >.10) by weight grouping. Final 56-day plasma tocopherol increased linearly (P <.01) with level of vitamin E supplementation. Plasma tocopherol of non-supplemented steers decreased (P =.01) from an average initial concentration of 1.66-1.16 ug/mL at day 56. It is concluded that vitamin E supplementation of calf-fed Holstein steers receiving a conventional steam-flaked corn-based growing-finishing diet is not expected to enhance growth performance.