【作者】 张继杰；

【导师】 周安国； 王之盛；

【作者基本信息】 四川农业大学 ， 动物营养与饲料科学， 2008， 硕士

【摘要】 本试验通过研究饲粮蛋白水平对断奶仔猪生产性能、血清脂质含量、脂肪酸合成关键酶含量、基因表达及其代谢产物的影响,旨在从代谢水平上证明蛋白质水平对脂肪酸合成的调控作用。试验采用单因素试验设计,选取24±1日龄断奶的DLY仔猪24头,按照体重一致,公母各半的原则随机分配到3个处理组中,每个处理4个重复,每个重复两头猪。各处理日粮能量一致,蛋白水平分别为23%(高蛋白)、20%(中蛋白)和17%(低蛋白)。试验日粮主要参照NRC(1998)5-10kg仔猪营养需要进行配制,试验期28天。试验结果表明:(1)高蛋白日粮显著提高仔猪生产性能,中低蛋白日粮则无明显差异。(2)高蛋白日粮趋向于降低仔猪血清甘油三酯,总胆固醇,极低密度脂蛋白-胆固醇水平,中低蛋白日粮对血脂水平的影响差异不显著。(3)高蛋白日粮极显著降低仔猪肝脏中FAS的活力(p＜0.01),极显著降低肝脏和脂肪组织中ACC蛋白水平及其mRNA的相对表达量(p＜0.01)。(4)高蛋白日粮有降低肝脏丙二酰辅酶A趋势,与FAS相比ACC对脂肪酸合成的限速能力较弱。本实验结果证明,高蛋白日粮对脂质代谢的调控作用,主要是通过抑制ACC的基因表达和降低FAS的酶活,降低脂肪酸合成,减少体脂沉积,提高生产性能;与FAS相比ACC对脂肪酸合成的限速能力较弱。肝脏脂质代谢的丙二酰辅酶A途径对日粮蛋白水平引起的脂质代谢的影响较小,不具备调控脂质代谢的作用。更多还原

【Abstract】 To explore the role of diet protein level on regulating lipid metabolism,the current trials were designed to determine the effects of diet protein level on performance,blood lipid,the relative enzymes’ activities and mRNA expression and their production.A one-factor experiment was designed.24 DLY weanling pigs averaged 6.25kg were randomly allocated to 3 treatments with 4 replicates,each replicate 2 pigs.The same DE of the experiment diets were disigned and protein level were 23%(high level),20%(middle level ),17%(low level).The experiment diets were prepared according NRC(1998) nutrient requirements of 5-10kg pigs.he experiment lasted 4 weeks.The results showed that:(1):Diet of high protein level can improved performance,there were no different between middle protein level and low protein level.(2):Diet of high protein level tend to decrease serum TG,TC and VLDL-C,there were no different between middle protein level and low protein level.(3):Diet of high protein level can decrease FAS activity extremely significantly in liver(p＜0.01);decrease ACC protein level and its mRNA correspondence quantity extremely significantly in liver and adipose tissues.(4):Diet of high protein level tend to decrease Malonyl-CoA in liver tissue,and compared with FAS,ACC was poor in limiting synthesis of fatty acid.It is concluded that:high protein regulate lipid metabolism mainly by inhibit ACC gene expression and decrease the activity of FAS,so that inhibit the fatty acid synthesis of weanling pigs and decrease lipidosis,improve their performance; Compared with FAS,ACC is poor of controlling fatty acid synthesis;There is no effect of M-CoA on lipometabolism caused by protein level.更多还原