Selenium in alfalfa
Selenium deficiency is caused by low Se intake, which correlates to limited Se availability in soils, and thus, forages grown on those soils.
Livestock forage, whether range, pasture, or hay, generally reflects the available Se content of the soil on which it is grown.
Forage supplemented with Se can be fed to livestock. Concerns about Se toxicity are much less, intake of Se is more consistent, and retention of Se is much greater when feeding a Se-fortified forage.
The potential for using Se as a fertilizer to increase forage-Se concentrations in livestock feeds has been demonstrated by over 15 years of research at Oregon State University.
OSU finds that adding selenium to fields planted with alfalfa will allow the perennial forage crop to “take up” the important mineral in its tissues, providing better feed for calves and other livestock.
The findings are particularly important, researchers say, because selenium delivered through plants in an organic form is much safer than directly feeding selenium to calves in an inorganic form, such as salt. Jean Hall, a professor in the College of Veterinary Medicine at OSU. ”When I say organic, I mean it is incorporated right into an amino acid so the selenium replaces a sulfur in methionine. It actually has selenium in that molecule instead of sulfur.
The researchers fed selenium-fortified alfalfa to calves and compared their growth to control animals. Several weeks later, the calves with supplemented diets had higher blood selenium content levels and the calves fed selenium-fortified alfalfa also weighed up to 10 percent more than calves fed alfalfa without selenium. Furthermore, weight growth by the calves increased with additional selenium