【作者】 潘翠玲；

【导师】 陈伟华；

【作者基本信息】 南京农业大学 ， 基础兽医学， 2002， 硕士

【摘要】 仔猪消化道发育的成熟程度及机体免疫水平的高低直接影响到仔猪今后的生长，从而影响到仔猪的育成率。仔猪在哺乳期，其消化道发育还不成熟，消化机能不完善，由母体获得的被动免疫力在3周龄后逐渐降低，而其主动免疫功能在4-5周龄时还很弱。断奶会使仔猪肠道的形态结构及功能受影响，引起机体免疫力下降，提早断奶会使这种变化更加严重，因此开发价廉而又能促进仔猪消化道发育、增强机体免疫功能的哺乳仔猪代乳料或早期断奶仔猪料显得极为重要。本实验从体内和体外两方面研究了酪蛋白、面筋蛋白和大豆蛋白的胃蛋白酶解物对21日龄早期断奶仔猪消化生理及免疫功能的影响；对10日龄仔猪胃窦分泌胃泌素的影响以及对仔猪外周血淋巴细胞转化的影响，为开发成本低而效果佳的哺乳仔猪代乳料或早期断奶仔猪料提供一定的实验依据。 一．酪蛋白、面筋蛋白和大豆蛋白酶解产物的制备及氮含量的测定 采用碱提酸沉法和氯化钠缓冲溶液洗涤法分别制取大豆蛋白和面筋蛋白，以蛋白质底物：胃蛋白酶=30:1的比例、pH=1.4，在37℃水解2小时，测得酶解产物的氮含量（W／V）如下：大豆蛋白酶解产物中的氮含量最高，为40.61％，其次是酪蛋白的，为20.44％，而面筋蛋白的为6.13％。 二．酪蛋白、面筋蛋白和大豆蛋白酶解产物对10日龄仔猪胃窦分泌胃泌素的影响 采用体外组织表面灌流法，研究含有与10umol／Lβ-GM₇等氮量的蛋白酶解物对10日龄仔猪胃窦分泌胃泌素的影响。实验结果表明：与对照组相比，实验组的三种蛋白酶解物对4头、10日龄仔猪胃窦胃泌素的分泌均有促进作用，且在作用的第一个10分钟内促分泌作用较强，而从刺激的第二个10分钟开始促分泌作用逐渐减弱。其中大豆蛋白酶解物对仔猪胃窦分泌胃泌素的促进作用强于酪蛋白和面筋蛋白的酶解物。大豆蛋白酶解物组比对照组的胃泌素分泌分别增高99.98％、65.12％、30.45％和9.48％；酪蛋白酶解物组比对照组的胃泌素分泌增高分别为107.12％、56.26％、6.77％和0.72％；面筋蛋白酶解物组比对照组的胃泌素分泌分别增加34.66％、20.35％、5.56％和3.87％。 三．酪蛋白、面筋蛋白和大豆蛋白酶解产物对10日龄仔猪淋巴细胞转化的影响 采用³H-TdR掺入微量全血法，研究酪蛋白、面筋蛋白和大豆蛋白酶解物对10日龄仔猪外周血淋巴细胞转化的影响。实验结果表明：尽管4头猪的个体差异较大，但总趋势是三种蛋白酶解物均能促进PHA诱导的10日龄仔猪外周血淋巴细胞转化。其中，大豆蛋白酶解物对经PHA诱导的仔猪外周血淋巴细胞的促转化作用较强，其次是面筋蛋白酶解物，再次是酪蛋白酶解物。大豆蛋白酶解物组的刺激指数比对照组的增高20.96倍、11.65倍、0.74倍和0.39倍；面筋蛋白酶解物组的刺激指数比对照组的增高10.96倍、8.85倍、2.41倍和0.63倍。酪蛋白酶解物组的刺激指数比对照组的增高18.2倍、1.96倍、1.54倍和0.73倍。 四．添喂蛋白酶解物对早期断奶仔猪生长性能的影响 与对照组（28日龄断奶）仔猪相比，给21日龄早期断奶仔猪添喂一定量的大豆蛋 潘翠玲：添喂茵白酶解物对早朋断奶仔猪消化生理和免疫功能的影响白酶解物、添喂卜酪啡肽；溶液，能克服早期断奶应激引起的仔猪腑下降、腹泻和生长迟滞等不良现象，邯猪的采食量略有提高，并对早期断奶仔猪脏器的生长有一定的促进作用，但是体重的增加和小肠的增长与对照组的差异不显著；添喂面筋蛋白酶解物引起仔猪腹泻，对脏器的增重影响不大。添喂酪蛋白酶解物引起仔猪腹泻，略能提高仔猪脏器的相对重。五．添喂蛋白酶解物对早期断奶仔猪几种血清激素水平的影响 与对照组的仔猪相比，给ZI日龄早期断奶仔猪添喂大豆蛋白酶解物能提高早期断奶仔猪血清的胰岛素（高 68．13％，P刃．05）和瘦素（高 4．65％，P狈．of）水平，略能提高仔猪血清的胃泌素、T4和IL2的水平，略能降低皮质醇的水平，对T3影响不大．添喂面筋蛋白酶解物能提高早期断奶仔猪血清的瘦素（高15．12％，P叨．05）和胃泌素（高58．43o，P叨．of）水平，略能提高仔猪血清的胰岛素和o毛的水平，对h．几和皮质醇的水平没有明显改变．添喂酪蛋白酶解物可提高早期断奶仔猪血清的瘦素（11．63o，P＜0．05）、胃泌素和兀－2（高 12．970，P＜0．05）的水平，略能降低飞的水平，对其余的激素水平影响不大．添喂卜酪啡肽，溶液能提高早期断奶仔猪血清的瘦素门．0o，P刃．of)和胃泌素门．760，P叨．of)水平，略能降低皮质醇的水平，对胰岛素、T3、T4和IL2的水平影响不大．六．添喂蛋白酶解物对早期断奶仔猪消化道形态结构及酶的影响 与对照组的仔猪相比，给ZI日龄早期断奶仔猪添喂大豆蛋白酶解物、添喂面筋蛋白酶解物、添喂卜酪啡肽。液，能显著地使胃窦粘膜的厚度增加，可促进断奶仔猪小肠绒毛的生长，对十二指肠腺的发育以及十二指肠、空肠前段和回肠粘膜上皮内的杯状细胞的增生略有促进作用，对回肠派伊尔结的发育略有改邯用．添喂酪蛋白酶解物，对仔猪小肠缄毛的生长、隐窝深度的改善和肌层厚度的增加没有明显作用，对回肠派伊尔结的?更多还原

【Abstract】 The growth of piglet was directly influenced by digestive tract development and immunity competence of body, then the raising rate of piglet involved. In suckling, because piglet’s digestive tract was underdeveloped, its digestive function was unperfect, its passive immunity offered by the sow would weaken after three weeks’ old, while its active immunity would bring into play low up to four_five weeks’ old. Damaged intestinal configuration and function and lowered immunity of piglet were led by weaning , then more severe damages were resulted in early weaning. It is most essential that research and development of piglet feed which is cheap, can improve the digestive tract development and enchance immunity, can substitute milk or be used in early weaning . In vivo, the exeperiment was investigated to the effect of casein-, gluten, soybean protein hydrolysate on the digestive physiology and immunity of early weaning piglet in 21 days’ old, and in vitro , on the gastrin secretion of gstric antrum and the transformation of lymphocyte in 10 days’ piglet , in order to offer the accordings to develope the low cost and favorable effect of piglet feed substituting for milk or using in early weaning piglet. Part I Effect of casein, gluten and soybean protein hydrolysates on gastrin release of gastric antrumWith superfusion system, the research was investigated to the effect of protein hydrolysate on gastrin secretion of the gastric antrum of 10 days’ piglets, at the same nitrogen quantity of the P-CM7 (10nmol/L). Results indicated that all the hydrolysates could promote gastrin release in the experimental group, and effect was distinct within the first 10-minute after stimulation began, then lowered gradually from the second 10-minute. The role of soybean hydrolysate in stimulating grastin release was stronger than that of the others, compared with the control, gastrin was respectively increased by 99.98%, 65.12%, 30. 45% and 9. 48% in four piglets fed by soybean hydrolysate, in feeding gluten hydrolysate group, it was respectively increased by 34. 66%,20.35%, 5.56% and 3.87% , in feeding casein hydrolysate group, which was increased by 107. 12%, 56.26%, 6.77% and 0. 72% respectively. Part II Effect of casein, gluten and soybean protein hydrolysates on the transformation of lymphocyte in 10 days’ pigletThe effect of hydrolysate on the transformation of lymphocyte in 10 days’ piglet was studied by 3H-TdR method. Results showed that each of the three hydrolysates could promote the transformation of lymphocyte induced by PHA in 10 days’ piglet, though there existed obvious individual diversity among the four piglets. The soybean hydrolysate was of the highest action, then the gluten hydrolysate, finally the casein hydrolysate. Compared with each of the control groups, the stimulation indexes of the soybean hydrolysate group was increased 20.96 times , 11.65times, 0. 74 times and 0.39 times in four piglets respectively, of the gluten hydrolysate group, which was 10.96 times, 8.85 times, 2. 41 times and 0. 63 times respectively, and of the casein hydrolysate group, which was 1.82 times, 1.96 times, 1.54 times and 0.73 times respectively.PartHIEffect of feeding three protein hydrolysates on growth of early weaning pigletCompared with the control(weaning in 28 days’ old), the slow appetite, diarrhea and growth delayed of early weaning piglet were conquered by feeding soybean hydrolysate or 3-casomorphin7, the growth of visceras be promoted in some degree , but the piglet weight change was not significant . Feeding gluten hydrolysate or casein hydrolysate can lead piglet diarrhea , and has no obvious effect on the weight changes of visceras . Compared with each other in the experimental groups, the effect of feeding soybean hydrolysate promoting visecras’ growth is proir to 3 -casomorphin?, gluten hydrolysate and casein hydrolysate.PartlVEffect of feeding three protein hydrolysates on serum hormone level of early weaning pigletCompared with the control (weaning in 28 days’ old), in 21 day’s weaning piglet fe更多还原