| Summary: | 碩士 === 國立宜蘭大學 === 動物科技學系碩士班 === 98 === Pig weanling proceeds subjected to the environmental and physiological stress, which may raise the risk of gut inflammation and diarrhea, which is the critical in productive efficiency. Diet supplemented with Ganoderma lucidum fermented (GLF) have been found the improvement of growth performance and health of animals. However, the underlying mechanisms of GLF for growth and immunity are unclear. This study was to investigate the effect of variously doses of GLF supplemented on the growth, immune responses, and gut morphorology of weaned pigs. A total of sixty-four castrated pigs (28 day weaned, initial weight 7.81 ± 1.36 kg) randomly allotted to four dietary treatments with randomized complete block design. A trial of two replicates with 8 pigs per replicate (4 pigs/pen) in each treatment was conducted for 42 days feeding period in 2 phases (phase I, days 0 to 14; phase II, days 15 to 42). The four treatments including 0, 0.9, 1.8, and 3.6 g/kg GLF (0, 34, 68 and 136 mg/kg pure β-glucan based on 3.76% of β-glucan in GLF) was added to a corn-soybean meal basal diet. Animals were fed diet ad libitum and had free access to water. On days 7 and 14, all pigs were injected i. m. with 1 mg bovine thyroglobulin (BTg). All pigs were weighed biweekly and bled to analyze the immune responses of peripheral blood mononuclear cells (PBMC), neutrophil, immunoglobulin, and BTg-specific antibody. At the end of the feeding trial, 2 pigs per pen was randomly chosen and sacrificed to measure the lymphocyte proliferation and subpopulations of gut-associated lymphoid tissues (spleen, mesenteric lymph node, Peyer’s patches), the humoral (serum, bile, chyme, and feces) antibody concentrations, and the morphology of small intestine. The results showed that diet supplemented with GLF increased the ADFI during days 0 to 42 and decreased the diarrhea frequency during days 0 to 28. Diet supplemented with 1.8 g/kg GLF increased the ADG and FE about 10.38 and 3.33% during days 0 to 42, however, these differences were not significantly. Diet supplemented with 3.6 g/kg GLF enhanced the monocytes of blood on day 14 but decreased the lymphocytes on day 42 as compared to both of the control and 0.9 g/kg GLF groups. The phagocytic rate of neutrophils on days 14 and 42 and NO secretion of splenocytes on day 42 (P = 0.08) were increased. Diet supplemented with 1.8 g/kg GLF enhanced the proliferation of PBMC inducing by con A or PHA on day 28 (P < 0.05) but tended to decrease the proliferation by PHA stimulated of mesenteric lymph node on day 42 (P = 0.06). Supplemented with GLF was presented quadric effect on the lymphocyte subpopulation at days 14 and 42. The CD8 lymphocyte subpopulation of PBMC was increased in diet supplemented with 1.8 g/kg GLF on day 14 as compared with the control group. Additionally, CD25 subpopulation was increased in 0.9 g/kg GLF group as compared to the other groups on day 42. Dietary treatments significantly affected the concentrations of humoral immunoglobulin and BTg-specific antibody. Diet supplemented with 0.9-3.6 g/kg GLF decreased the concentrations of serum IgM (P = 0.10), serum BTg-specific IgM (P < 0.05), and feces IgA (P = 0.10) on day 14. Diet supplemented with 0.9 g/kg GLF also decreased the concentration of bile IgA on day 42, in contrast did not affect the chyme IgM or IgA concentration. Dietary treatments significantly affected the morphology of small intestine. Diet supplemented with 1.8 g/kg GLF increased the size of sialomucin goblet cells at the villus portion of jejunal and neutral goblet cells at the villus portion of ileum, however, treatments had the similarly effect on the villus height, crypt depth, and sulfomucin goblet cells. Conclusively, diet supplemented with 1.8 g/kg GLF slightly increased the ADG and FE due to increase ADFI. Supplemented 1.8 g/kg GLF also expand the goblet cells in small intestine, enhance innate and cellular immunity, and suppress humoral immunity of weaned pigs.
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