The Effects Of Phenanthroline On The Ruminal Metabolism Of Protein, Protein Profile In The Duodenal Digesta, And Protein Digestion In The Small Intestine Of Sheep

A non- isotopic dual- marker method based on Cr2C>3 and PEG to measure duodenal and ileal diesta flow was developed, which was used in the successive experiments, in the first place. The effects of phenanthroline on ruminal metabolism of protein were studied by both in vitro and in vivo methods. In the last part of the study, we compared the effects of formaldehyde protection and phenanthroline on the utilization efficiency of diet protein.Part 1. The feasibility of measuring duodenal and ileal digesta flow by a non-isotopic dual-marker methodFour castrated little tail Han ram fitted with permanent rumen, duodenum, and ileum fistula were used to examine the feasibility of a non- isotopic dual- marker method to measure duodenal and ileal digesta flow. The sheep were fed pellet diet by automatic feeder. During measurement of digesta flow, chromic oxide (Cr203) and polyethylene glycol-4000 (PEG) were added in the pellet diet. Chromic oxide and PEG were put into the rumen through rumen fistula directly when measuring the recovery rate of markers in faces. The recovery rate of chromic oxide and PEG were 95.75% and 91.48% respectively. After feeding the pellet diet containing digesta markers, the relationships of chromic oxide in the ruminal, duodenal, and ileal digesta can be described by the equations respectively: y=0.5303 (l-e'01071x) (r=0.8357) ; y=0.3051(l-e'00550x) (r=0.9542) ; y=0.8316 (1-e"00728") , (r=0.9387) and the relationships of chromic oxide in the ruminal, duodenal, and ileal digesta's fluid can be described by the equations respectively: C(t) =0.08 (l-e'043t) (r=0.2828), C(t) =0.03 (l-e'U8t) (r=0.6557), C(t) =0.19(l-e-?2:t)(r=0.6505) G PEG concentrations in the ruminal, duodenal, and ileal digesta changed with time following equations y=0.5269 (l-e'00950x) (r=0.8022), y=0.3829 (l-e'?384x)(r=0.7593 ), and y=0.8765 ( 1 -e"?639x) (r=0.9569) respectively, and PEG concentrations in the ruminal, duodenal, and ileal digesta's fluid changed with time following equations C(t)=0.46(l-e-0.060t) (r=0.8668),C(t)=0.47(l-e-0.018t) (r=0.9207), C(t) =1.10(l-e"oo:2t)(r=0.9599) . The averages of duodenal and ileal digesta flow rate measured in this experiment were 10.0543 + 1.7265 1/d and 5.6295?.9019 1/d respectively. The mean retention time of chromic oxide in the rumen was 88 hours, and the mean retention time of PEG was 40 hours.Part 2. Effect of Phenanthroline on the Fermentation of Mixed Ruminal Microorganisms in vitroRuminal fluid was extracted from four-castrated little tail Han rams through ruminal fistula. The concentration of phenanthroline on gas production, ammonia concentration, true protein content, and disappearance rate of dry matter were examined in a in vitro fermentation experiment. The result indicated that supplementation of phenanthroline can severely inhibit gas production and ammonia concentration. True protein content was depressed by supplementation of phenanthroline but increased with phenanthroline concentration. The disappearance rate of DM was decreased by the supplementation of phenanthroline. Equations calculated from regression analysis are: Y=-16.75X+29.52 (r=0.7976, p<0.05),X: concentration of phenanthroline (mmol/1),Y: gas production (ml); Y=-0.5757X+3.3036 (r=0.8384, p<0.05),X: concentration of phenanthroline (mmol/1),Y: concentration of ammonia N (mg/100ml); Y = -10.14X + 55.08 (r=0.9275, p<0.01),X : concentration of phenanthroline (mmol/1),Y : disappearance of dry matter (%); Y=1.35X+11.45 (r=0.8423, p<0.05),X: concentration of phenanthroline (mmol/1),Y: concentration of true protein (%) ?Part 3. Effect of phenanthroline concentration on ruminal metabolismFour castrated little tail Han rams fitted with permanent rumen fistula were used. The experiment was divided into four successive periods, i.e. control and period I , II and El, each period last 10 days. The sheep were fed pellet diets containing 0 g/Kg , 0.8g/kgx 1.0 g/kg 1.2 g/kg of phenanthroline respectively. Rumen fluid was taken through the rumen fis...