| Summary: | 碩士 === 國立宜蘭大學 === 動物科技學系碩士班 === 96 === Sodium butyrate (NaB) is one of energy source for epithelial cells of intestinal, and plays a central role in maintaining the mucosal barrier in the gut. Threonine (Thr), an indispensable amino acid for pig nutrition, is also main role for the maintenance of mucosal proteins because some of these proteins contain a high amount of Thr in their peptide backbone. The disadvantage of immature in gut causes poor growth during weanling of pigs. The aim of this experiment was to test whether the effects of diets supplemented with NaB and Thr on growth performance, intestinal development, and immune responses of weaned pigs.
In Exp. 1, forty-eight pigs (21 day weaned) were randomly allotted into four treatments including 0, 0.15, 0.30, and 0.45% non-protected NaB. Pigs were fed 2 pigs per pen, and each treatment had 6 pens for 21 days. At the end of the Exp., all of the pigs were sacrificed to investigate the effects of dietary treatment on intestinal structure and function as well as gut-associated lymphocyte tissues immune responses. The results showed that dietary supplemented with NaB did not affect the growth performance, organ weights, small intestine mucosal morphology, mucosal DNA concentration, digestive enzymes, the intestinal microbial ecosystem, blood composition, and humoral IgA concentration of weaned pigs. Interestingly, dietary supplemented with 0.15% NaB had the highest proliferation by phytohemagglutinin (PHA) stimulation on lymphocytes of Peyer’s patch. Dietary supplemented with 0.45% NaB increased jejunal digesta mucin concentration about 21% compared with the control group (P > 0.05), while significantly increased IFN-γ secretion of peripheral blood monocytes (PBMC) and decreased in proliferation of splenocytes by PHA stimulation were observed.
In Exp. 2, sixty-four pigs (21 day weaned) randomly allotted to four treatments including fat-coated NaB (days 0 to 14: supplemented with 0.09%; days 15 to 42: supplemented with 0.06%), Thr (days 0 to 42 supplemented with 0.10%), NaB plus Thr and control groups. Pigs were fed 4 pigs per pen, and each treatment had 4 pens. And on day 21, 2 pigs per pen were randomly sacrificed to investigate the effects on gut physiology and immune responses. The remain pigs were fed to the end of the Exp. The data revealed that dietary NaB and Thr supplement failed to affect the growth performance, serum urea nitrogen and immunoglobulin concentrations, bile, small intestinal mucosa, and digesta IgA concentration during 42 days period of weaned pigs, but dietary supplemented with Thr decreased the variation of body weight (P < 0.01). On day 21, dietary supplemented with NaB and Thr were significantly increased plasma Thr concentration (P < 0.02) and ileal amino-peptidase N and alkaline phosphatase (P < 0.05), while dietary supplemented with Thr was sustained enhance plasma Thr concentration on day 42. On day 21, dietary supplemented with Thr increased the villus acidic goblet cell size of jejunum, and NaB plus Thr had a synergistic effect on the villus neutral goblet cell numbers and area of jejunum. Dietary supplemented with NaB had significantly increased the splenocyte proliferation by PHA stimulation (P < 0.05) and decreased in CD4% of spleen, while dietary supplemented with Thr was significantly increased PBMC proliferation by concanavalin A stimulation (P < 0.05) on day 21.
Conclusively, dietary supplemented with unprotected NaB has no effects on small intestinal structure and functions, and dietary supplemented with 0.45% NaB has significantly increased IFN-γ concentration, but dietary supplemented with fat-coated 0.09-0.06% NaB during phase 1 and phase 2 has improved immune response of weaned pigs. Dietary supplemented with Thr is increased jejunal acidic goblet cell numbers, ileal alkaline phosphatase, and PBMC proliferation of weaned pigs, but no effects of interaction with NaB on intestinal development and immune responses of weaned pigs.
|
|---|
