摘要：

旨在探明五指山猪断奶后仔猪肠道的应激变化以及对肠道黏膜AA转运载体表达量的影响。共用五指山仔猪24头,分别在断奶0天、断奶后第3,7,10天进行屠宰,并收集仔猪血清、小肠肠段和黏膜。测定其血液免疫指标、小肠形态学和肠道黏膜AA转运载体相关基因表达量。结果表明:与断奶前相比,断奶后第3天肠绒毛断裂稀疏,十二指肠和回肠绒毛高降低,空肠和回肠绒毛表面积的变化差异显著。断奶后第7天后绒毛高等数值均有好转;血清中总蛋白、白蛋白、球蛋白和葡萄糖含量在断奶后显著降低,天门冬氨酸氨基转移酶、总胆固醇、乳酸脱氢酶和天门冬氨酸氨基转移酶含量差异显著;断奶后血清中二胺氧化酶、D-乳酸和脂多糖变化显著;断奶后小肽转运载体PepT1相对表达丰度按照十二指肠、空肠和回肠的顺序依次进行增加,酸性AA转运载体EAAT3相对表达丰度在肠道中不显著,中性AA转运载体B⁰AT1、ASCT2和rBAT在空肠以及回肠中的相对表达量更高,碱性AA转运载体CAT1、y+LAT1和4F2hc,在断奶后十二指肠的表达量降低,载体在回肠的表达中相对更加稳定。综上所述,早期断奶应激引起五指山仔猪绒毛缩短和隐窝增生等明显肠道变化,血液免疫蛋白及二胺氧化酶、D-乳酸和脂多糖等含量降低,同时肠道AA转运载体表达量变化,尤其断奶后第3天各项指标变化明显,但随着断奶日龄增长至第10天逐渐恢复,仔猪免疫力增强,肠道黏膜通透性增加。

关键词: 五指山猪, 断奶应激, 肠道, 氨基酸转运载体, 免疫

Abstract:

The aim of the study was to investigate the stress changes in the intestinal tract of piglets after weaning and the effect on the expression of AA transporter carriers in the intestinal mucosa of Wuzhishan pigs.A total of 24 Wuzhishan piglets were used, which were slaughtered on 0 days of weaning,and 3,7 and 10 days after weaning, and serum, small intestinal segments and mucosa were collected. Their blood immunity indexes,small intestine morphology and intestinal mucosa AA transporter carrier-related gene expression were determined.The results showed that compared with the pre-weaning period,the intestinal villi were sparsely broken,the duodenal and ileal villi heights were reduced in the 3rd day after weaning,and the differences in the changes in the surface area of jejunal and ileal villi were significant.All the values of villi height improved after the 7th day after weaning; the content of serum total protein,albumin,globulin and glucose decreased significantly after weaning,and the differences in aspartate aminotransferase,total cholesterol,lactate dehydrogenase and aspartate aminotransferase content were significant; the changes in serum diamine oxidase,D-lactic acid and lipopolysaccharide were significant after weaning; the relative expression abundance of the small peptide transporter PepT1 increased in the order of duodenum,jejunum and ileum after weaning,the relative expression abundance of the acidic AA transporter EAAT3 was not significant in the intestine,the relative expression of the neutral AA transporters B⁰AT1,ASCT2,and rBAT was higher in the jejunum as well as in the ileum,and the basic AA transporters CAT1,y+LAT1 and 4F2hc,had reduced expression in the duodenum after weaning,and the vectors were relatively more stable in ileal expression.In summary,early weaning stress caused obvious intestinal changes such as shortening of villi and crypt hyperplasia in Wuzhishan piglets,and decreased the content of blood immunoproteins and diamine oxidase,D-lactic acid and lipopolysaccharides,etc.At the same time,the expression of intestinal AA transporter carriers was changed,especially in the 3rd day of the post-weaning period,and all the indexes changed significantly,but with the growth of weaning day old up to the 10th day of the weaning period,it gradually recovered,and the piglets' immunity increased,and the permeability of the intestinal mucosa increased.

Key words: Wuzhishan pig, Weaning stress, Intestinal tract, Amino acid transporter, Immunity