Genetic Variability for Mineral Element Concentration of Crested Wheatgrass Forage

Grass tetany is a complex metabolic disorder that causes substantial livestock production losses and deaths in temperate regions of the world. It is caused by low levels of Mg or an imbalance of K, Ca, and Mg in forage consumed by animals. Development of grasses with improved mineral balance would be an economical means of minimizing losses from this malady. This study was conducted to determine if genetic variability exists among crested wheatgrasses, Agropyron cristatum (L.) Gaertner and A. desertorum (Fisher ex Link) Schultes, for forage Mg, Ca, K, Fe, Zn, Mn, Cu, Na, and P concentrations. Forage of spaced plants of 10 diverse crested wheatgrass stains was harvested from replicated plots at Lincoln and Alliance, NE, which differ markedly in climate, and analyzed for these minerals. There were genetic differences among strains over locations for Ca, Mg, and Fe concentrations in the forage. There were differences among strains within locations but not over locations for K. Strain differences in Zn, Mn, Cu, Na, and P concentrations of the forage were not significant (P \u3e 0.05) when averaged over locations. Calcium and Mg were positively correlated (r = 0.40). These results indicate that it should be possible to breed crested wheatgrass with increased Mg and Ca concentrations in its forage, thus reducing grass tetany potential