The Effect of Zinc Methionine in a Mineral Mixture on Gain and Incidence of Footrot in Steers Grazing Native Grass Pastures11Contribution No. 95-73-E from the Kansas Agricultural Experiment Station

Crossbred steers (266 kg avg BW) were allotted to groups and provided either a control mineral mixture or one containing 2.5% zinc methionine while grazing late-spring burned native grass pastures in early summer to determine whether zinc methionine would reduce the incidence of footrot. Four pastures were provided per treatment per year, and the treatments were rotated in each year of a 3-yr study. The steers were weighed individually in early morning at the start of the trial in April and again at the end in late July or early August. The pastures were grazed an average of 93 d. The mineral mixtures were fed in open wooden boxes, and intake was recorded weekly. The steers were checked once each week for signs of footrot. The steers receiving zinc methionine gained faster (1.27 vs 1.23 kg; P < .06) and had a lower incidence of footrot (2.45 vs 5.38%; P < .06) than the control group. However, the difference in gain between steers with footrot and nonaffected steers did not account for the total difference in gain. Zinc methionine at 2.5% of the mineral mixture improved steer gains and reduced the incidences of footrot.