Research On Feeding Evaluation And Its Methods For Some Herbages And Shrubs From Alpine Pasture

The experiment selected 3 yaks, by using in sacco and in vitro gas production methods, I determined the DM disappearing rates according to deferent digesting time of Elymus nutans-Uhe major breed of Jinqianghe alpine pasture. In sacco method showed that from 3rd hour to 48th hour of digesting range, the DM disappearing rate increased significantly, it increased from 25.8% to 58.50%, after 48 hour, the trend slowed down. Same results happened to in vitro gas production method, and relativity analysis showed a strong relationship between in sacco and in vitro gas production method (r=.9796, P<.01). So when in sacco method is applied for feeding evaluation of herbage, the in sacco period was set at 48 hours.By applying traditional method, I detected nutrition contents of 48 alpine herbages, shrubs and trees (leaves) at tasseling,flowering, seeding, and post-seeding stage. Among them, 13 are cultivated herbages, 21 are natural herbages, 5 are shrubs and 9 are twigs and leaves of arbors. Results showed that the average content of cultivated grasses is DM 95.66%, CP 8.87%, no ash acid wash fiber 34.22%, CF 3.06%, crude ash 6.68%, Ca 1.52%, and P .16%; for the legume from cultivated pasture, DM is 93.98%, CP is 15.55%, acid wash fiber is 27.65%, crude fat is 3.15%, Ca is 2.64%, P is .29%, and crude ash is 12.98%, averagely. DM of natural pasture is 94.27%, CP is 11.76%, acid wash fiber is 30.78%, crude fat is 3.11%, Ca is 2.84%. P is .28%, and crude ash is 11.90%, averagely. Average content of shrub is DM 94.33%, CP 9.69%, acid wash fiber 37.75%, crude fat 3.94%, Ca 3.26%, P .14%, and crude ash 4.91%. For the leaves and twigs of trees, the average figure is, DM 94.27%, CP 13.42%, acid wash fiber 23.86%, crude fat 3.71%, Ca 3.86%, P .29%, and crude ash 14.19%. The ordering for CP content, and acid wash fiber content is legume>twigs + leaves>natural herbages>shrubs>grass, and shrubs>grass>naturalherbage>legume>twigs + leaves respectively. There is no significant deference in crude fat, Ca and P content.The average DM disappearing rate for cultivated grass, legume, natural herbage, shrub, twigs + leaves is 60.47%, 82.81%, 77.44%, 53.99%, and 71.94%, respectively; for CP, is 76.31%, 82.81%, 90.93%, 60.02%, and 76.21%, respectively; while for acid wash fiber is 42.61%, 59.46%, 51.79%, 18.91%, and 45.36%, respectively; disappearing rate for Ca is 68.23%, 88.96%, 86.46%, 65.71%, and 73.94%, respectively; and disappearing rate for P is 60.00%, 89.49%, 89.33%, 76.05%, and 80.41%, respectively. The ordering for DM disappearing rate is legume>natural herbage>twigs + leaves>grass>shrub; for CP disappearing rate isnatural herbage>legume>twigs + leaves>grass>shrub; for Ca disappearing rate is legume>natural herbage>twigs + leaves>grass>shrub; for P disappearing rate is legumOnatural herbage>twigs + leaves >shrub>grass.For the Elymus nutans predominated pasture, I detected yak intake by using retained grazing in combination with all feces collection, the intake is 3513.20 ?279.85g/herd/d, the average digesting rate for DM of these three yaks is 55.58 + 5.87%, for CP is 59.80?.29%, for ADF is 44.49?.44%, for OM, Ca and P is 63.19+4.09%, 46.11+4.68%, and 48.70 + 3.67%, respectively.