Study On The Nutrient Of Pennisetum Rich And The Trend Of Ruminal Degradation In Vitro

In order to select high-quality cultivars and the best cutting height of Pennisetwn Rich.Research were conducted to analysis the biological production of the Pennisetwn Rich, the situation of the nutritional value and the artificial rumen degradability and to provide some scientific support.There were mainly four parts in the study. Firstly,study on the nutrient value of different varieties of Pennisetwn Rich. Secondly, study on the nutrient value of different cutting height of Guimu-1 hybrid Pennisetwn pwpurewn. Thirdly, study on the trend of artificial ruminal degradability in vitro of different varieties of Pennisetwn Rich. Fourthly, study on the trend of artificial ruminal degradability in vitro of different cutting height of Guimu-1 hybrid Pennisetwn purpureum. The results were showed as follows:Firstly,by contrasting the performance of all varieties of Pennisetum Rich, it was found that the Rough Stem Pennisetum purpureum had the highest hay yield among five Pennisetum Rich and its total output of hay grass was reach to 41．08t/hm~2．In other kind's descending order was Guimu-1 hybrid Pennisetum purpureum, Pennisetum Hybrid, King Grass and the Small Stem Pennisetum purpureum. The results showed that except hay yield the Rough Stem Pennisetum purpureum's was significantly higher than that of the Small Stem Pennisetum purpureum (P< 0．05) .other's had no significant difference (P>0．05) .Pennisetum Hybrid and Guimu-1 hybrid Pennisetum purpureum got smaller stem leave ratio than others. Under 1．2m～2．0m cutting height condition, the cutting height of 2．0m had the maximun hay yield which was up to 26．22t/hm~2 and significantly higher than that of 1．2m and 1．6m. With Guimu-1 hybrid Pennisetum Purpureum's cutting height increasing, its output of fresh grass,hay yield,content of DM and stem leave ratio were also increasing. Secondly, by contrasting the nutrient value of different varieties of Pennisetum Rich, it was found that Guimu-1 hybrid Pennisetum purpureum had the highest CP content which reached to 12．25% .Pennisetum Hybrid's ADF,NDF,ADL content was 59．65%,33．53% and 5．46%.respectively,which was significantly lower than those of other breeds (P<0．05) .The highest digestibility of DM after its 24h artificial ruminal fermentation was Pennisetum Hybrid and its DM digestive rate reached to 55．12%.The DM digestive rate of Guimu-1 hybrid Pennisetum purpureum was 53．05%.The Small Stem Pennisetum purpureum had the lowest DM digestive rate.Pennisetum Hybrid also had the highest digestibility of ADF,NDF, and Guimu-1 hybrid Pennisetum Purpureum followed. The Small Stem Pennisetum purpureum was less than other breeds.The Pennisetum Hybrid had the highest cumulative gas production but it was no significant difference among different breeds (P>0．05) .Thirdly, the nutrient value of the Guimu-1 hybrid Pennisetum Purpureum was varied from different cutting height.With Guimu-1 hybrid Pennisetum Purpureum's cutting height increasing, its CP content was gradually reduced,NDF, ADF and ADL content were gradually increased. The cutting height of 1．2m had the highest CP content which reaching to 18．35%. But there were no significant difference between the treatment group 1．2m and 1．6m(P>0．05) . The cumulative gas production after 24h fermenting, digestibility of DM and NDF reduced with the cutting height increased. The aggregate digestible dry matter in cutting height of 1．2m,1．6m and 2．0m was 1．26t/hm~2, 11．53t/hm~2 and 14．26t/hm~2,respectively,which was showed that 2．0m was Superior to 1．2m and 1．6m.According to above analysis, we found that Guimu-1 hybrid Pennisetum purpureum and Pennisetum Hybrid had higher nutrient value, which was worth of application.The best cutting height of Guimu-1 hybrid Pennisetum Purpureum was 2．0m under 1．2m～2．0m cutting height condition.