| In order to reveal the developmental dynamics of the digestion and immunological barrier function in small intestine of yak, and to find the differences and similarities between Yak and plain cattle, the mucosal structure of Yak small intestine and the morphous, distribution and development pattern of the mucosal-immunity associated cells in Yak small intestine were studied comparing with those in cattle using conventional histology technique. Results are as follows:1 From birth to adult, significant changes were found in the structure of the intestinal mucosal membrane. The length of villus and the V/C values decreased significantly while the depth of the crypt, the thickness of mucosa, and the thickness of muscular layer increased(P<0.05) in 30-day-old Yak intestine comparing with those in 1-day-old Yak intestine. The length of intestinal villus, the thickness of mucoua membrane, the thickness of muscular layer and the V/C values increased from 30-day to adult. These results indicated that the digestive and absorptive ability in Yak intestine increased after 30-day-old.Compared with cattle, the length of intestinal villus, the V/C values, the thickness of the mucousal membrane and the muscular layer were all significantly lower in 1-day-old, 30-day-old Yak. While all of these in 180-day-old yak were similar with cattle.2 The number of and ileum of yak increased gradually from birth to adult and got a peak in adult. The number of intraepithelial lymphocytes in adult yaks was as much as 2.13 times, and 2.57 times (P﹤0.05), in duodenum, jejunum and ileum, respectively, than those in 1-day-old yak.The number of intraepithelial lymphocytes in duodenum and jejunum of 1-day-old yak were similar with those of 1-day-old cattle, but that in yak ileum is 57.53% as cattle. The number of intraepithelial lymphocytes in all intestine segments of 30-day old and 180-day-old yak was higher than those of cattle at the same ages(P﹤0.05).3 The number of goblet cells decreased significantly from 1-day old to 30-day-old from birth to adult and got a lowest point in 30-day-old. The number of goblet cells increased from 30-day-old to adult, and got a peak in adult. The number of goblet cells in adult yaks was as much as 3.32 times, and 2.70 times and 4.01 times (P﹤0.05), in duodenum, jejunum and ileum, respectively, than those in 30-day-old yak.The number of goblet cells in yak was similar with those of cattle from 1-day old to 30-day-old, and the number of goblet cells in duodenum of yak were only 50.24% and 50.76% of the cattle(P<0.05). The number of goblet cells in jejunum of yak as much as 1.22 times than those of cattle(P<0.05).4 The number of the mast cells in the duodenum and jejunum was the least 1-day old yak, while the number increased significantly after then and reached the most in adult. The number of the mast cells in the ileum was the least in 30-day-old, and the number began to increase later,and reached the most in adult(P<0.05).The number of the mast cell in the duodenum and jejunum of yak in 1-day-old to 30-day-old was significantly less than that of the cattle. The number of the mast cell in ileum was significantly more than cattle except at the day 30(P<0.05).Conclusion: There were a difference of the structure of the intestinal mucous membrane and the morphological structure, quantitative distribution of the mucosal-immunity associated cells, between yak and cattle, because of the different of genera and physiological functions. During the developmental process of the yak and cattle,there were a series of adaptive changes to the structure of the intestinal mucous membrane and the morphological structure, quantitative distribution of the mucosal-immunity associated cells, and disparate a different growth tendency. Between birth to 30-day-old is an important period of the later development and adaptive phase. Through self adaption the general condition, the structure of the intestinal mucous membrane and the morphological structure and mucosal-immunity were consummated and improved in little time, which showed stronger growth than cattle .
|
PDF Full Text Request