Evaluation Of Nutritional Value Of Hybrid Pennisetum And Study On Combination Effect

In this paper,the Grazing Index(GI)and Cornell Net Carbohydrate and Protein System were used to evaluate the quality of corn stover,Leymus chinensis and Hybrid Pennisetum,and the nutritional value of Hybrid Pennisetum was compared and analyzed.According to the nutrient comparison of the three roughages,different ratios were applied,and then the combined fermentation results of the three kinds of roughage single fermentation results and the three roughage different combinations were studied by using the in vitro batch culture method.After in vitro batch fermentation,the fermentation ratio was selected according to the fermentation parameters,the experiment adopts the Latin square design,and three sheep with permanent rumen fistula are selected,and three parallel samples were selected for each fermentation time point.A nylon bag test was conducted to study the effect of the formula on the rumen nutrient degradation rate and rumen fermentation parameters of cashmere goats.Results were as follows:(1)The results showed that Hybrid Pennisetum was rich in crude protein and mineral elements,with low NDF and ADF content and high lignin content compared to corn stover and Leymus chinensis.From the analysis of the characteristics of CNCPS,Hybrid Pennisetum could be digested and absorbed in carbohydrate fraction less than the other two roughages,and the protein fraction of Hybrid Pennisetum can be digested and absorbed was slightly higher.GI analysis results showed that the quality of Hybrid pennisetum was higher than the other two Hybrid Pennisetum>Leymus chinensis>corn stover(P<0.05)?(2)Single roughage and Different roughage combinations were designed according to the economic status and nutrient composition of the three feeds,The results of in vitro batch fermentation for 24 h showed that(1)the pH value of single roughage at each time point,Leymus chinensis >Hybrid Pennisetum > corn stalk;cumulative gas production at each time point was Hybrid Pennisetum>corn stalk>Leymus chinensis;ammonia nitrogen concentration was roughly Hybrid Hydrangea > Leymus chinensis >corn stalk;MCP concentration was early stage Leymuschinensis>Hybrid pennisetum>corn stalk,late Hybrid pennisetum> Leymus chinensis >corn stalk.(2)The comprehensive indicators of the combined effects of different combinations refer to the three indicators of gas production,ammonia nitrogen concentration and MCP concentration in vitro fermentation for 24 hours,Results were as follows:The MFAEI in GroupB(Hybrid Pennisetum + Leymus)was ranked as B3>B2>B1,the results showed that the combined effect was stable and high when the content of Hybrid pennisetum was 60%.And based on the results,it was used as part of the E group fermentation;The combined effect result in group C(Corn stalk + Hybrid pennisetum)was C3>C1>C2>C4,that was,the higher the content of Hybrid pennisetum,the content of 60% was more favorable for fermentation;The MFAEI result of group D was D4>D2>D3>D1,which indicates that the lower the content of corn stalk,the better the combination effect,and the better the fermentation of the feed by microorganisms,which was beneficial to improve the digestibility of forage;In group E(Corn stalk + Hybrid pennisetum + Leymus chinensis)was E4>E2>E1>E3.The combination showed that the smaller the content of corn stalk,the higher the content of hybrid pennisetum,the more favorable for fermentation,the better the combined effect result.Based on the results of the combined combination effect and the their fermentation results,the three groups of C3,D4 and E4 with good fermentation effect were selected.(3)Three sets of roughage combinations screened by rumen in vitro batch fermentation were used to carry out semi-inner nylon bag test,and the points of 3,6,9,12,18,24,48 and 72 h were selected and determiningthe degradation of DM,ADF,NDF and CP in the rumen,The results showed that: the DM degradation rate in the E4 and D4 groups was significantly higher than that in the C3 group(P<0.05),but the effective degradation rate was the highest in the E4group;The degradation rates of three groups of NDF in the whole digestion period were significantly higher in the D4 and E4 groups than in the C3 group(P<0.05),and the effective degradation rate in the D4 group was significantly higher than that in the E4 and C3 groups(P<0.05);The degradation rate of ADF in the whole digestion stage was similar to that of NDF degradation,but the effective degradation rate of E4 was higher;The degradation rate of CP was higher in the E4 and D4 groups than in the C3 group at the time of digestion stage(P<0.05),but there was no significant difference between the three groups at 3~6 h(P>0.05),and the effective degradation rate was the highest in group E4.so according to the degradation of DM,NDF,ADF,CP,the best group was E4.In summary,Hybrid Pennisetum was a high-protein pasture with excellent quality and good palatability.From the results of in vitro fermentation experiments and semi-in vivo nylon bag experiments,Whether combining Hybrid Pennisetum with high fiber content roughage(corn stalk)or with high fiber forage(Leymus chinensis),the higher the content of hybrid pennisetum,the better the combination effect index.Under the premise of cost saving,three kinds of roughages were combined in different proportions,the more the hybrid pennisetum content,the better the combined effect result.