| Antibiotics are widely added into feed during pig production,which affects pork quality and safety,causes environmental pollution and brings harm to human health and public health.One method is to replace antibiotic feed with probiotics fermented feed.In this paper,after treatment with antibiotics-free probiotics fermented feed,histomorphology observation and counts change of mucosal immune-related cells were used to study on the effects of the feed on the intestinal absorption and mucosal immune functions,which would provide a basis for exploring the mechanism of fermentation feed without antibiotic to promote digestion and disease-resistant ability.In this study,a total of 120 newborn piglets were randomly divided into the test group and control group.Each group had 6 replicates with 10 pigs per replicate.In the test group,10%,20%and 30%fermented feed were added to the feed during the weaning,growing and fattening stages with the same nutrition and energy levels with those of the control group.The control group was fed with the usual antibiotic feed.On 5d,15d,25d,44d,75d and 180d after treatment with the feed,one pig was randomly selected from each replicate for slaughter and duodenum,jejunum and ileum were collected for fixation with 4%paraformaldehyde.HE staining was used to observe intestinal mucosa morphology while PAS staining was applied to determine the number of goblet cells.Moreover,the numbers of M cells and CD3+T cells were determined by immunohistochemical staining.The results have shown that there were no significant differences between the test group and the control group in the gut mucosa morphology,villus length,crypt depth,villus crypt ratio(ratio glands down)and the number of goblet cells in the villus.mucosa morphology:the difference was not significant;villus length:Test duodenum from 25 days of age were slightly higher overall,but the difference was not significant(P>0.05),The length of villus was higher than that of the control group after the age of 15 days.At the age of 44 days,the experimental group was 7.19%higher than the control group,the difference was significant(P<0.05),In other days was not significant(P>0.05);the ileum differences compared to the control group and the test group at 44 days and 75 days was significantly(P<0.05),no significant differences in other days(P>0.05).Crypt depth:the test group was lower than the control group at 5d,15d,25d,44d,75d and 180d,but the difference was not significant(P>0.05);VL/DH:The duodenum and jejunum test group had no significant difference compared with the control group at 5d,15d,25d,44d,75d and 180d(P>0.05).The ileum was significantly higher in the 44th day test group than in the control group(P<0.05),other age difference was not significant(P>0.05).Small intestine villi goblet cells:at the age of 44 days,the duodenum,jejunum and ileum test group were significantly lower than the control group(P<0.01),at 75 days of age only duodenum test group was significantly lower than the control group(P<0.01),The other age difference was not significant(P>0.05).this show fermented feed without antibiotics can promote intestinal digestion and absorptionThe evaluation of epithelial lymphocytes(IEL),M cells and CD3+T cells was evaluated.In 44 days the number of IEL duodenum and jejunum in the test group than the control group,the difference was significant(P<0.01),75 days experiment in duodenum,jejunum and ileum IEL numbers higher than the control group,(P<0.05).There was no significant difference between the two groups(P>0.05).The number of M cells and CD3 + T cells was significantly higher than that of the control group(P<0.05),but the difference was not significant(P>0.05).Indicating that no antibiotic fermentation feed on the intestinal mucosal immune function has a certain promotion function.In summary,this test study show that feeding fermented feed without antibiotics,can increase the duodenum,jejunum and ileum villi length,crypt depth reduction,improved gland down ratio,an increase of absorption area of the inner wall of the small intestine,and reduces The number of villous goblet cells,increased intestinal epithelial cells and nutrients contact opportunities to enhance the intestinal absorption function;and can increase the small intestinal epithelial lymphocytes,M cells and CD3+ T cells.thereby enhancing the small intestine mucosal immunity.Indicating that no antibiotic fermentation feed can improve the digestion and absorption of nutrients,improve intestinal mucosal immunity.Based on the results of the study on the growth promotion of antibiotic fermented feed and the improvement of immune function,it was proved that antibiotic-free feed could replace antibiotic feed for pig production. |
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