Effects Of Dietary Crude Protein Levels On Ruminal Fermentation And Nutrient Degradation Of Sheep In Artificial Simulation

This trial simulated rumen internal environment using DFCCS-II dual-flow continuous culture system, The four diets with crude protein levels of 12%,14%,16%,18% respectively were fermented to investigated the effect of on ruminal fermentation, gas production, nutrients degradation rate in Sheep. By measuring the gas production and microbial indicators of different levels of crude protein diets comprehensive evaluated, It provided the basis for optimization of dietary protein level.The dual-flow continuous culture system was used in the experiment to research on effect of four diets to sheep rumen environment parameters. The results showed as follows:with the increase of dietary crude protein levels, rumen fluid pH tended to increase, feeding after 2 h,18% was significantly higher than other levels (P<0.05); There were no significant effects on acetate, propionate and butyrate with dietary crude protein level (P>0.05), acetate/propionate were significantly decreased,2 h after feeding,12% was significantly higher than 18% group (P<0.05), Total VFA was increased at first then decreased, and Total VFA concentration of 16% level was significantly higher than 12%,18% levels(P<0.05), feeding after 2 h, Total VFA concentration of 16% level was significantly higher than 12%,18% levels(P<0.05); the concentration of NH3-N was highly significant rised(P<0.01); the concentration of BCP increased at first and then decreased, and BCP concentration of 16% level was significantly higher than those of other levels,after feeding 2 h,16% was significantly higher than other levels of (P<0.05); dietary crude protein levels on rumen the number of internal parasite no significant differences(P>0.05).The Ankom RFS system was used in the experiment to research on effect of four dietary crude protein levels on gas production from the rumen. The results showed as follows:Culture in hours 3 and 6, the dietary crude protein levels of 12% significantly (P<0.05) higher than other groups;Culture in hours 3, the dietary crude protein levels of 12%,16% significantly (.P<0.01),higher than diet of 14% and 18%; Culture in hours 6,12% group was significantly higher than 14%,18%(P<0.01); Culture in hours9-12,16% group of gas production is highest,16% group was significantly higher than 14%(P<0.01), the tended of total gas production was diets of 18%>12%>16%>14%.The Ankom Daisy II automatic culture system in vitro was used in the experiment to research on effect of four dietary crude protein levels on digestibility of nutrients. The results showed that:different dietary crude protein on dry matter digestibility was not significant (P>0.05). Culture in hours3-12, CP degradation rate increased with increasing dietary crude protein levels,18% group was significantly higher than the 12% level (P<0.01), Culture in hours 24, the difference between groups was not significant (P> 0.05). With the improvement of the level of crude protein, NDF and ADF degradation rate significant increase (P<0.05), and no significant differences between the groups 16% and 18%(P>0.05).Under the condition of this test, the artificial ruman was fermentation stability with various dietary crude protein levels, crude protein levels have difference effect on the rumen environment, gas production, the digestibility of nutrients.