Effect Of The Differce Diets Of Concentrate To Forage Ratio On The Amino Acids Metabolism In Liver And Relative Hormone Response Of Nonlactating Goats

The study was conducted to investigate effect of difference diets of concentrate to forage ratio on the amino acids metabolism in liver and relative hormone response of ruminants. Nonlactating goats was chosen as the animal model,techniques for chronic vascular fistula and blood flow was used to study dynamic changes,transformation and reveal the metabolism discipline of milk protein precursors in the liver.In trial1,effects of difference diets of concentrate to forage ratio on Lys、Met and BCAA metabolism in liver and PDV of nonlactating goats. Six nonlactating goats, averaging40±2kg at the beginning of study,were surgically implanted with vascular catheters the splanchnic tissues. Briefly, Teflon catheters encased in silastic were implanted into the portal vein,hepatic vein and femoral artery. Surgeries were performed at least21d before the start of the experiment.Then the animals were randomly divided into2groups and used in a crossover design and each animal was raised in indoor metabolism cage.Prefeeding period15d and sampling period5d were included in each phase.Two diets were formulated using the breeding standard of NRC and reference of China.Corn and soybean meal were chosed as the major of concentrate,as well as Chinese wildrye and alfalfa were chosed as the major of forage. Diets were divided into two groups(HC:concentrate to forage6:4,HR:concentrate to forage4:6) according to the ratio of concentrate to forage.Each animal can drink freely and was fed quantitative at8:00and20:00each day.Vascular fistula were cleared with heparin solution3times one day to ensure the smooth flow of the blood.The results showed that,compared with HR,the concentration of Lys,Met and Val in portal vein of HC were significantly increased (P<0.05),however the concentration of Ile and Leu were unaffected by diets;the concentration of Lys and Met in hepatic vein and femoral artery of HC were increased significantly (P<0.05),the concentration of Val in hepatic has the tendency to increase (0.05<P<0.1),the concentration of Ile and Leu in hepatic were same as the portal vein.The concentration of BCAA in femoral artery was unaffected by diets.Compared with HR,the flow of amino acids in portal were all unaffected by diets;the flow of Met in hepatic tended to increase (0.05<P<0.1),whereas the flow difference of BCAA and Lys were not significant.The flow of Lys and Met in femoral artery of HC increased significantly,but the flow of BCAA were unaffected by diets.In trial2, the effect of different diets of concentrate to forage ratio on gluconeogenesis and glucogenic amino acids metabolism in liver of nonlactating goats.The experimental design was the same as that of trial1.The results showed that, comparing with HR,the concentration of EAA and glucose in portal vein of HC tended to increase (0.05<P<0.1),the concentration of NEAA and TAA were unaffected bu diets.The concentration of glucose in hepatic of HC increased significantly,whereas EAA tended to increase;the difference of NEAA and TAA were non’t significant;the concentration of glucose in femoral artery of HC increased significantly,but EAA,NEAA and TAA were not unaffected by diets.Comparing with HR,the flow of EAA in portal vein of HC tended to increase,however NEAA,TAA and glucose were non’t significant;the flow of glucose in hepatic vein and femoral artery increased significantly,but EAA,NEAA and TAA were unaffected by diets. The net portal apparence of EAA,NEAA,TAA and glucogenic amino acids were positive,whereas urea and glucose were negative.This indicated that there is a net output of plasma amino acids in PDV between two groups,however there is a net use of urea and glucose.Glucose utilized by PDV in HC was80%higher than HR,whereas urea was lower76.9%.The difference of net portal apparence of each item in two diets were both not significant.The net hepatic release of EAA,NEAA,TAA and glucogenic amino acids were all negative,however urea and glucose were both positive.This indicated that there is a net utilization of plasma amino acids in hepatic,whereas urea and glucose were net output.Comparing with HC,the net hepatic release of glucogenic amino acids in HR tended to decrease (0.05<P<0.1),urea in HC was72.2%lower than HR,glucose in HC was16.3%than HR. The net gut plus hepatic output of amino acids in HC were all higher than that of HR.In contrast, the net gut plus hepatic output of urea and glucose in HR were both higher than that of HC.Compared with HR,the concentration of glucagon tended to increase(0.05<P<0.1); the concentration of insulin in HC was10.02%higher than HR.The difference of flow of insulin and glucagon was both not significant.In trial3, the effect of different diets of concentrate to forage ratio on GH, IGF-1and biochemical parameters in plasma of nonlactating goats. The experimental design was the same as that of trial1.The results showed that, the plasma flow and concentration of GH in HR were both higher than HC, moreover the concentration of GH in HR was22.9%higher than that of HC.The concentration of GH in HC and HR ranged from4-6ng-mL-1and5-12ng·mL-1respectively.The concentration and flow of IGF-1in HR were greater than that in HC,furthermore, the concentration of IGF-1in HR was20.5%higher than HC.Between5sampling time points,the concentration of IGF-1in HC and HR ranged from40-55ng-mL-l and50-70ng-mL-1respectively.Compared with HR,the concentration of GOT in portal vein,hepatic vein and femoral artery of HC tended to increase (0.05<P<0.1),whereas the concentration of GPT was unaffected by diets.The difference of concentration of total protein in portal vein,hepatic vein and femoral artery was not significant.The net portal apparence of total protein in HC was higher than HR,whereas the net hepatic release of total protein in HR was higher than HC.The net portal apparence,net hepatic release and net gut plus hepatic output of total protein were showed positive,this indicated that there was a net output of total protein in PDV and hepatic. The concentration of plasma ammonia in portal vein,hepatic vein and femoral artery of HR were all higher than that of HC.The concentration of plasma ammonia in portal vein were both higher than that in hepatic vein and femoral artery between two diets.The concentration of plasma ammonia in hepatic vein was75.5%lower than that in portal vein in HC,whereas HR was lower76.4%. The net portal apparence of plasma ammonia showed positive,indicated an output of plasma ammonia in PDV; the net hepatic release and net gut plus hepatic output of plasma ammonia showed negative,indicated an net utilization of plasma ammonia in liver and peripheral tissue.