【作者】 林桂娟；

【导师】 任继周； 王恬；

【作者基本信息】 南京农业大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 为探索乳源性活性肽对新生仔猪肝脏功能发育的影响，选用乳中自然存在的胰岛素和酪蛋白酶解产生的混合多肽进行试验，以新生正常仔猪和新生子宫内发育迟缓（intrauterine growth retardation，IUGR）仔猪作为试验对象。试验选择“苏太猪”初生仔猪13窝（每窝1-2头正常，1-2头IUGR）共50头，分为新生组（N）、牛乳组（M）、胰岛素组（Ⅰ）、酪蛋白组（C）和酪蛋白酶解物组（CH），每组5头正常仔猪、5头IUGR仔猪，N组仔猪出生后立即宰杀取样。M组喂牛乳，Ⅰ组在牛乳中添加66IU·L^-1胰岛素，C组用1.5％酪蛋白溶液取代10％（v／v）的牛乳，CH组用1.5％酪蛋白酶解液取代10％（v／v）的牛乳，人工饲喂3天，每3小时喂一次，饲喂量为每次30mL·kg^-1BW，3天后宰杀取样，测定肝脏和血浆中生化指标和酶的活性。 试验结果表明，人工饲喂3天后，仔猪肝脏中蛋白质含量CH组(正常仔猪216.57±48.38mg·g^-1，IUGR仔猪231.66±31.95mg·g^-1)和C组(正常仔猪160.74±38.86mg·g^-1，IUGR仔猪184.49±19.54mg·g^-1)都极显著高于N组(正常仔猪116.64±10.56mg·g^-1，IUGR仔猪109.06±13.91mg·g^-1)（P＜0.01），CH组显著高于C组（P＜0.05），IUGR仔猪有高于正常仔猪的趋势（P＞0.05）。血浆中尿素氮浓度，CH组(正常仔猪104.35±35.18mg·L^-1，IUGR仔猪230.67±84.45mg·L^-1)有低于C组(正常仔猪132.73±41.78mg·L^-1，IUGR仔猪306.95±72.26mg·L^-1)的趋势（P＞0.05），正常仔猪有低于IUGR仔猪的趋势（P＞0.05）。肝脏GOT活性，IUGR仔猪CH组显著高于C组（P＜0.05），正常仔猪CH组有高于C组的趋势（P＞0.05）。饲喂3天后，四组仔猪肝糖原含量均极显著下降（P＜0.01），血浆中FFA和胰岛素浓度、肝脏中LDH、GPT、CAT活性极显著提高（P＜0.01），而血糖浓度、肝脏中脂肪酶、HL、G-6-PD、ICD、SOD活性没有显著变化（P＞0.05）。血浆中胰岛素水平，正常仔猪Ⅰ组(10.26±2.02mIU·L^-1)显著高于M组(7.81±1.34mIU·L^-1)（P＜0.05），IUGR仔猪Ⅰ组较M组略有提高（P＞0.05）。 结果表明，仔猪出生后肝脏蛋白质、糖、脂代谢以及肝脏抗氧化功能发生着激烈变化，酶解酪蛋白多肽可促进仔猪肝脏蛋白质的合成，对IUGR仔猪生后发育具有一定的补偿作用，酶解酪蛋白多肽和胰岛素对仔猪糖、脂代谢以及肝脏抗氧化功能均无显著影响，胰岛素对仔猪肝脏蛋白质代谢影响不显著。更多还原

【Abstract】 The aim of this study was to explore the effect of milk-borne bioactive peptides on the functional development in the liver of neonatal pigs. Insulin and casein hydrolysate were fed to experimental animals including normal weight (NW) and intrauterine growth retardation (IUGR) neonatal pigs. Fifty neonatal pigs were selected from thirteen litters (one or two NW and one or two IUGR neonatal pigs from one litter) and divided into newborn group (N), milk group (M), insulin group (I), casein group (C) and casein hydrolysate group (CH). The piglets in group N were killed and sampled immediately after birth. Piglets in groups M and I were fed milk and milk supplemented with 66IU-L-1 insulin, respectively. The piglets in groups C and CH were fed milk substituted 1.5% casein and 1.5% hydrolysed casein solution for 10% (v/v) milk, respectively. The piglets were fed by 30ml/kg body weight every three hours. The piglets were slaughtered and sampled after feeding three days. The enzyme activities and biochemical indices were analyzed according to appropriate methods.The results were demonstrated that the concentrations of protein in liver significantly increased in group CH (216.57 48.38mg-g-1 in NW pigs, 231.66 31.95mg-g-1 in IUGR pigs) and in group C (160.74 38.86mg-g-1 in NW pigs, 184.49 19.54mg-g-1 in IUGR pigs) than that in group N (116.64 10.56mg-g-1 in NW pigs, 109.06 13.91mg-g-1 in IUGR pigs) (P<0.01) after artificially reared three days. Liver protein content was higher in group CH than that of group C (P<0.05) and it also showed a tendency to be higher in IUGR pigs than that in NW pigs (P>0.05). The concentrations of plasma urea nitrogen showed a tendency to decrease in group CH (104.35 35.18mg-L-1 in NW pigs, 230.67 84.45mg-L-1 in IUGR pigs) than that of group C (132.73 41.78mg-L-1 in NW pigs, 306.95 72.26mg-L-1 in IUGR pigs) (P>0.05). It showed the same tendency between NW and IUGR pigs (P>0.05). The activity of GOT in the liver of IUGR pigs in group CH markedly increased than that of group C (P<0.05), and it also showed the same tendency betweengroup CH and group C in NW pigs (P>0.05). After three days, liver glycogen contents in M, I, C and CH group all decreased significantly than that of group N (P<0.01). In contrast, there was a marked increase in the concentration of plasma FFA and insulin and the activities of LDH, GPT and CAT of the liver in M, I, C and CH group than those in group N (P<0.01). The content of plasma glucose and the activities of lipase, HL, G-6-PD, ICD and SOD were showed no significantly difference in M, I, C and CH group when compared with the N group (P>0.05). The concentration of plasma insulin in group I (10.26 2.02mIU-L-1)was higher than that in group M (7.81 1.34mIU-L-1) in NW pigs (P<0.05), and it showed same tendency in IUGR pigs (P>.05).In conclusion, great changes took place in proteometabolism, glycometabolism, lipometabolism and antioxidation function in the liver of piglets during the early postnatal period. The casein hydrolysate significantly stimulated protein synthesis in the liver and upgrowth in IUGR neonatal pigs, however, insulin was no significantly effect on the protein synthesis in the postnatal liver. Casein hydrolysate and insulin showed no significantly effect in glycometabolism, lipometabolism and antioxidation function in the liver of neonatal pigs.更多还原