Evaluation of multiple reticulorumen selenium pellets as a health risk in growing Hereford steers

Five groups of Hereford steers were monitored for 293 days. One group of 3 was not given selenium supplementation; the other 4 groups of 3 steers each were given 2, 4, 6, or 8 reticulorumen selenium pellets. Health, body weight, and blood selenium concentration were monitored during the study. At the finish, steers were slaughtered, and various tissues from the carcasses were analyzed for selenium content. Initial blood selenium concentration did not differ significantly among groups. However, significant (alpha = 0.01) difference among means was detected during the early period of rapid increase in blood selenium concentration in steers of supplemented groups. Means of maximal blood selenium concentration also differed among groups; however, even the highest value, 0.253 micrograms/g, was lower than the 3 micrograms/ml reported in chronic clinical cases of toxicosis in the literature. Carcass analysis indicated significant (alpha = 0.05) differences in selenium concentrations among treatment groups for almost all tissues tested. Only kidney samples (7.9 micrograms/g) from steers of the 8-pellet treatment group exceeded published normal values (7.6 micrograms/g). Health variables for most dates were not significantly different among groups, and selenium toxicosis was not evident in any steer. Analysis did not indicate risk to human beings consuming tissues from these steers.