Blood mineral status of grazing Tibetan sheep in the Northeast of the Qinghai–Tibetan Plateau

We investigated the macro-mineral status in free-grazing Tibetan sheep (Ovis aries) and their forage diets. The study was conducted in 4 counties in the northeast of the Qinghai–Tibetan Plateau. Forage samples and blood serum from 20 sheep in each county were collected in July (summer) and December (winter), and analyzed to determine the concentration of the main macro-minerals (Ca, K, Mg, Na and P). Macro-mineral concentrations varied with season, but values for forage were below the recommended levels for P and K in one or more counties in winter and for Na was low during both summer and winter for all counties. Similarly, serum samples were found to be within marginal range of P, with the exception of Tianzhu County (TC) in winter, and serum Na were all below the marginal level in both summer and winter in all counties. The results indicate that the winter forage in particular is insufficient in macro-minerals and that this may lead to the observed mineral deficiencies and marginal deficiencies in Tibetan sheep in these areas. Supplementary minerals may therefore play a role in balancing the minerals available from the forage in winter and lead to increases in animal production on the Tibetan Plateau.