The Effect Of Ration Protein Levels On Digestion And Absorption Of Nutrients In Sheep

Three mature male Merino sheep(about 35 kilograms) fitted with permanent cannula in the rumen,T-type cannula at the proximal duodenum and terminal ileum were fed with different protein levels diets. The levels were respectively 7.0%, 10.0%,12.8% and 15.5%. Collecting each sheep,s passage in the deudeum and ileum during each experiment. Lignin was used as marker. The research was concerned about if feed protein levels could effect on nutrient digestion in forestomach and absorption in small intestine to measure flow of passage and nutrients.The results showed that when the sheep were fed with 7.0%, 10.0%,12.8% and 15.5% protein level diets respectively, their CP degradation in forestomachs were–49.44±18.04, 2.48±13.75, 15.34±10.09 and 25.08±8.58% respectively, cellulose digestibility were 72.0±3.6, 76.2±2.6, 82.3±2.0 and 81.7±3.3% respectively, half-cellulose digestibility were 76.5±3.8, 73.9±3.6, 69.8±3.9 and 66.5±4.3% respectively.The rate CP flowing to the small intestine of intake CP were 149.44±18.04,97. 52±13.75,84.66±10.96 and 74.92±8.58% respectively, RUP rate of the total protein were 37.33±14.25,29.88±12.93,38.43±2.61 and 31.17±7.29% respectively, MCP rate were 109.70±6.25,63.45±4.05,42.36±7.86 and 39.21±2.48% respectively, OM of passage were 43.87±3.47,43.35±4.36,43.71±4.15 and 45.67±3.21% respectively.Apparent digestibility of CP in small intestine were 134.76±19.32,78.43±14.81, 66.20±11.53and55.07±8.72% respectively, The total amino acid reaching small intestine of intake CP were 96.04±7.0,78. 06±14.7, 59.74±5.3 and 54.12±5.7% respectively, and digestibility of it were 86.04±2.05, 81.73±4.26, 82.02±1.56 and 81.88±3.26% respectively, The apparent aborptivity of OM in small intestine were 29.0±3.3, 27.6±5.2, 29.7±4.4 and 31.0±3.8% respectively.The results of experiment showed that the CP levels of diets affected the degradation of CP in forestomachs (Y=8.4326x-97.134,r=0.8686),therefore they affected the total CP rate (Y=-8.4326x+197.13,r=0.8686)and the whole amino acid rate(Y=-5.1098x+129.86, r=0.8966)flowing to small intestine and MCP rate (Y=-8.2951x+157.62,r=0.9204). But they have no apparent effect on the OM degradation, digestibility of cellulose and half-cellulose in forestomachs . So we should regard diet CP level and intake CP as one of the effective factors when evaluating the CP of diets degradation degree in forestomachs , the CP rate flowing to the small intestine ,the amino rate and the productive rate of microorganism in forestomachs.