Abstract: The aim of this study is to discuss the effect of rumen NH3-N and MCP of Tibetan sheep with controlreleasing urea diet. Four two-year old Tibetan sheep fitted with permanent rumen fistula were fed quantificational different CP diet(containing urea diet(CP%=22.12%), without urea diet(CP%=22.02%), controlreleasing urea diet(CP%=21.97%) respectively every period. The results indicated that: pH and NH3-N concentration change quickly in rumen of Tibetan sheep with contain urea diet in a day, but slowly with without urea diet and control-releasing urea diet. Changing range of MCP is great, but releasing speed of energy and NH3-N is synchronous, compounding quantity of MCP is very much. There is terribly remarkable differences between control-releasing urea diet and containing urea diet, so is there between control-releasing urea diet and without urea diet (P<0.01). pH,NH3-N concentration and MCP content in rumen of Tibetan sheep with control-releasing urea diet is better than those of contain urea diet and without urea diet, that's show control-releasing urea diet is well about adding CP diet for Tibetan sheep and it is safe and high efficient CP nutrition diet.

Key words: CP diet; rumen pH; rumen NH3-N; MCP