The lack of knowledge of diet composition and nutritional status
of sheep in different seasons has restricted the development of
sustainable grazing systems in China. In northern china, sheep
suffer from exposure to extend periods of nutrient deficiencies, in
some cases, up to 7 months of the year. Therefore, it is important
that grazing systems are designed to make the best use of the
nutrients supplied by the native pasture during the short period of
abundance during the spring and summer. The feed intake of
grazing sheep is difficult to estimate. However, the discovery that
different herbage species contain unique fingerprints of alkanes has
revolutionized the ability for scientists to determine the intake of
different pasture species by grazing animals