Effect Of Different Levels Of NFC/RDP And Sulfur In Diets On Artificial Rumen Fermentation

The objective of this study was to investigate the effects of the compound use of different levels of NFC/RDP and sulfur on rumen fermentation and diet degradation by artificial rumen fermentation in vitro. The study was composed of3experiments:In experiment1, the CP degradation characteristics of9raw materials was studied, at the same time determine the nutrient contents of the9materials. Based on the parameters obtained from the above studies, diets (diet A) with the same NFC and different NFC/RDP value (3.35,4,4.8, respectively) and diets(diet B) with the same RDP and different NFC/RDP value (3.35,4,4.8, respectively) were formulated. In experiment2and3, Holstein cows were chosen to provide rumen juice. The sulfur concentration were0.15%,0.2%,0.25%and0.3%respectively with NaSO4in diet A or B, this study was assigned to12treatments with a3×4completely random grouping experiments by double factors, rumen pH, NH3-N concentration, gas production, bacteria protein number, VFA composition and the degradation rate of diet DM, CP, NDF and ADF were determined by artificial rumen fermentation in vitro. The result was as follows:Experiment1, the effective degradation rate of alfalfa hay, rapeseed meal, soybean meal, cottonseed meal, corn, corn straw, rice powder, DDGS and L.chinensis were65.04%,51.23%,50.56%,42.72%,37.69%,28.03%,25.77%,20.78%and19.43%respectively. The slow degraded part and its degradation rate of rapeseed meal, soybean meal, cottonseed meal and corn were higher than the other raw material expected L.chinensis.Experiment2, rumen fermentation with diet A as the substrate showed that pH value reduced significantly in4h (P<0.05), at12h,24h (P<0.01); there were no obviously change on NH3-N concentration, acetate and propionate, butyrate concentration was improved significantly(P<0.01); there was no significant difference in gas production except for4h (P>0.05);it’s significant difference in bacteria protein number except for4h(P<0.05); there were no different between degradation rate of DM and that of NDF(P>0.05), while significant different was observed between degradation rate of CP and that of ADF(P<0.05). Sulfur affected significantly on pH value, NH3-N, gas production, propionate, butyrate, bacteria protein number and the degradation rate of DM, NDF, ADF(P<0.01); significant influences of sulfur on acetate concentration and CP degradation in4h,8h,12h were observed (P<0.05). On the whole, for the treatment of4of the NFC/RD value, bacteria protein was improved significantly(P<0.05), but butyrate concentration was reduced significantly(P<0.05); pH, gas production, propionate and butyrate concentration, bacteria protein and degradation rate of DM, CP, NDF and ADF increased significantly for the proper sulfur supplement (level of0.2-0.25%)(P<0.05), but the NH3-N and acetate concentration reduced.Experiment3, effects of diet B on pH, gas production, propionate, butyrate, bacteria protein, degradation rate of ADF were significant different(P<0.01). NH3-N concentration was significant changed in8h,12h(P<0.05), in24(P<0.01), acetate, DM degradation, CP degradation in4h were different significantly(P<0.05). The influence of sulfur on pH(expected in2h), NH3-N concentration(in12h,24h), NDF(in8h.12h) were significant(P<0.01); effects of sulfur on gas production, propionate, butyrate, bacteria protein number and the degradation rate of DM, ADF, CP(expected inl2h) were significant(P<0.05); there was no significant change on acetate concentration expect in2h. On the whole, when the NFC/RDP value was4, pH, gas production, acetate, bacteria protein number were increased (P<0.05), and NH3-N, propionate and butyrate concentration were decreased, the degradation rate of DM, NDF and ADF were increased; the proper sulfur supplement (level of0.25%) might increase pH, gas production, propionate, butyrate, bacteria protein number, and reduced NH3-N concentration, which also can increased degradation rate of DM、CP、NDF and ADF.From the experiment we could get the conclusion that all of these indexes showed that there was an interaction between the NFC/RDP and sulfur in diets.The treatment with NFC/RDP value was4and the level of sulfur was0.25%can improve rumen environment, promote the degradation of diet nutrition significantly. NFC was better than RDP on improving rumen environment and rumen fermentation and promoting feed degradation rate when NFC/RDP value was same.