MINERAL STATUS OF GRAZING SHEEP IN THE DRY AREA OF MIDLAND CHINA

In the present study, nutritional status of some minerals in sheep grazed on native pasture was investigated in dry area, Ningxia district, of the People's Republic of China. Samples of some forages and blood of sheep were collected for two seasons, dry (March) and rainy (August) seasons. The Ca contents of forages (wheat straw, green-pea straw and some wild grasses) were relatively high as compared with that required ordinarily as standard, but on the contrary, the P content was much lower than that of standard. Consequently, Ca/P ratio was very high in cost of the roughages sampled in the region. Trace elements, Cu and Zn, content of forage samples were fairly low, and the contents of Mo and Fe were fairly high, particularly in some wild grasses, when the values were compared with that required normally. The Ca level in blood of sheep was in a range accepted as normal, and the other macro minerals(Mg and P) were contained at relatively high levels as compared with the values observed ordinarily, but not at a toxic level. With trace minerals, the plasma Fe level was extremely high as compared with the standard level, although there were no disorders due to toxicity, and Mo level in plasma was a little lower than the lower limit described as a normal. The plasma levels of other trace elements (Cu, Zn and Se) in all the animals were within the range accepted as normal. There would be no clear differences in mineral nutrition of sheep between dry and rainy seasons. These results could suggest that there is no severe unbalance and/or imbalance, and grazing sheep in the Ningxia area of midland China have no problems relating to the nutritional status of minerals.