Study On The Effects Of Feeding With Different Concentrate To Forage Ratios On Endotoxin Concentration And Immune Activation Characteristics In Rumen Fluid Of Sheep

The endotoxin concentration and immune activation characteristics was studied in rumen fluidof sheep fed with different ratios of concentrate to forage.Experiment Ⅰ: Free endotoxin,bacterial number,immune activation characteristics andphosphatase activity in ruminal fluid of sheep fed with different ratios of concentrate to forage.SixChinese Merino (Xinjiang type) ram,1.5year-old, fistulated permanent rumen fistul, was selectedand fed with4ratios of concentrate to forage31:69,39:61,43:57,59:41.Free endotoxin content,thequantity of bacteria,immune activation characteristics and phosphatase activity were determined.The results showed that free endotoxin content in rumen fluid was exponential relationship withdietary concentrate ratio (fitting equation is y=3.6862e0.0441x,orrelation coefficient r=0.9795).Thetotal number of bacteria in rumen fluid was exponential relationship with dietary concentrate(fitting equation is y=1.3842e3.1128, correlation coefficient r=0.9938). The differences bewteenTNF-α production by RAW264.7and rumen fluid from sheep fed with different ratios ofconcentrate to forage were not significant.Activity of acid phosphatase was higher than that ofalkaline phosphatase in rumen fluid of sheep. Activity dynamic of acid phosphatase is similar withthat of alkaline phosphatase in rumen fluid of sheep fed with the same concentrate ratio.Experiment II: Effect of dephosphoralation on immunity of LPS from E.coli. RAW264.7wasstimulated by dephosphoralated LPS and production of TNF-α was determined.The results showedLPS from E.coli was dephosphoralated by acid phosphatase. TNF-α production stimulated by thedephosphoralated decreased significantly.