Supplementing organic and inorganic selenium on yearling cattle performace and tissue selenium concentrations

摘要

In an 84-day experiment, Angus calves were supplemented in a concentrate mixture with organic and inorganic selenium at two levels each (0.1 and 0.3 ppm). There was a difference (P<0.05) among treatments with the organic 0.1 mg/kg treatment resulting in higher weight gains (161 kg) than all other treatments. There were no differences (P>0.05) among the other four treatments. There were differences (P>0.05) among treatments in plasma selenium concentrations, with the 0.3 mg/kg Se-yeast giving the highest values, followed by the 0.3 mg/kg selenite, then the 0.1 mg/kg Se-yeast, while the 0.1 mg/kg selenite and the control had the lowest but similar values. Plasma selenium concentrations of control animals tended to decrease with time. The selenium treatments tended to increase plasma concentrations at 28 days and then started decreasing slightly. The 0.3 mg/kg Se-yeast treatment, however, showed less tendency to decline with time. At no time were plasma selenium concentrations adequate. Liver selenium concentrations differed (P<0.05) among treatments, with the highest level of supplemental organic selenium (0.3 mg/kg) higher than all other treatments. Animals receiving 0.3 mg/kg selenium as selenite had higher liver selenium than the control or 0.1mg/kg selenite treatments.