| Summary: | 碩士 === 國立中興大學 === 動物科學系所 === 96 === Many reseachs demonstrated that vitamin D3 could modulate the absorption of calcium and improve performance of animal. There are also many researcher treated the effects of vitamin D3 on immunology recently. Those studys were mainly aimed at mammals such as rat, pig and human. Thus, the purpose of this study was aimed at poultry to evaluate the efficiency of Hy-D® on broilers. Post-hatch broilers(Arbor Acres) were randomly allocated to two treatment. A commercial diet and the commercial diet supplementation with Hy-D® (0 to 21 day of age: 69 ppm; 21 to 39 day of age: 34.5 ppm) were fed from 0 to 39 day of age. The results showed that no significant effects of Hy-D® in commercial diet on weight gain, feed intake and feed conversion, but during 21 to 39 age the feed intake in the Hy-D® supplemented group was lower than the control group(P<0.1). The results of gut morphology showed that Hy-D® can slight decrease the relative weight of small intestine. Except for ileum at 28-day-old, duodenum and jejunum at 35-day-old, the villi: crypt ratio in Hy-D® group was significantly higher than control. In the part of humoral immunity, the serum total IgA concentration downside at 21-day-old(P<0.1)and the serum Salmonella-specific IgG titer in Hy-D® group were significantly lower than control at 14-day-old . The viable numbers of the Salmonella typhimurium E29 vaccine strain administred orally to 7 and 14-day-old bird were 5×109 cfu/bird. The results showed that oral administration of the Salmonella typhimurium E29 vaccine strain observed on significant different for weight gain between control and Hy-D® group. Hy-D® can slight increase the Salmonella-specific IgG、IgA及IgM titer in serum. In the part of celluler immunity, polymorphonuclear leukocyte(PMN)isolated from control and Hy-D® group. The phagocytic potential was not different between the control and Hy-D®chick. In vitro PMN from control chick were incubated with Hy-D® solution diluted 0, 10, 100 folds for 6 hours. The result showed that no significant effects of Hy-D® in cell culture medium were observed for the phagocytic potential. In conclusion, Hy-D® in commercial diet can improve small intestine morphology, was beneficial to digestion and absorption of nutrition, but it was not resulted in better performance in this study. It may be affected by environment or other factors. Uninfected Chicks fed commercial diet with extra addition of Hy-D® had lower level of serum total IgA at 21-day-old and Salmonella-specific IgG at 14-day-old avoided unnecessary energy costing. After Salmonella typhimurium E29 vaccine, Hy-D® chicks could product more Salmonella-specific IgG、IgA及IgM to advance efficiency of immunity system.
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