Effects of β-glucan supplementation of diet on immunity and resistance to coccidiosis of New Zealand White rabbit

• Main Authors: Tsai-Tzu Chen, 陳綵慈
• Other Authors: Kuo-Lung Chen
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/63062089904041462408

碩士 === 國立嘉義大學 === 動物科學系研究所 === 94 === The purpose of this study was to investigate the effect of β-1,3-1,6-glucan supplementation of weaning or/and pregnant diet on immune response and resistance to coccidiosis of weaning New Zealand White (NZW) rabbits. For trial 1 and 2, 30 four-week-old NZW rabbits were used respectively, and a total of 21 rabbits were used in trial 3. Animals were assigned into three dietary treatments in trial 1 and 2 which were proved the diet supplemented with either 0 (control), 0.032 or 0.064% of β-glucan diets until 9 weeks of age. In trial 3, animals were fed on the β-glucan supplemented diets of either 0 (control), 0.064 and 0.128% until 9-week-old. For trial 4, NZW pregnant does around day 10 post copulation were fed same levels of the β-glucan diets as trial 3. The healthy bunnies weaned at 4 weeks of age were selected from each doe group and fed the same diet as their doe until 53-day-old. In trial 2, the rabbits were orally challenged with low dose (3.0×10^5) of sporulated oocysts of rabbit intestinal coccidian spp. at 6-week-old. The rabbits were orally challenged with high dose (5.8×10^5) of sporulated oocysts of rabbit intestinal coccidian spp. at 6-week-old in trial 3 and 4. The results from trial 1 showed that animals fed 0.032% β-glucan have a higher (P<0.05) antibody titer against Newcastle Disease vaccine (NDV) than the control group (P<0.05) on 8-week-old. Besides, the serum IgG concentration of 0.064% β-glucan group was higher (P<0.05) the control at 9 weeks of age. In trial 2, there was no difference on growth performances among 3 groups. In trial 3, the mortality was 71% (5/7), 57% (4/7) and 41% (3/7) for the control, 0.064% and 0.128% group by the 9 weeks of age after high dose sporulated oocysts challenge. The body weight and weight gain of the live rabbits at 9-week-old were increased with the level of β-glucan supplement increase, and the weight gain for 0.128% group were significantly (P<0.05) higher than the control. In trial 4, doe and kit were fed β-glucan diet. After high dose challenge, mortality was 40% (4/10), 30% (3/10) and 30% (3/10) for the control, 0.064% group and 0.128% group by the 53 days of age. Oocyst excretion for β-glucan oup was significantly higher than control (P<0.05). In immune response, CD8+ lymphocyte subpopulation for 0.128%β-glucan group was significantly higher (P<0.05) than other groups. Summarily, there was no difference on growth performances but there had higher IgG concentration and antibody titer for NDV while weaning diet supplemented with 0.064% β-glucan. After high dose of sporulated oocysts of rabbit intestinal coccidian spp. challenged, the mortality and growth performance were improved while weaning diet supplemented with 0.128% of β-glucan. Better growth performances were found when weaning and pregnant diet supplemented with 0.064 and 0.128% β-glucan. The peripheral blood CD8+ lymphocyte subpopulation and oocysts excretion, after high dose challenged, of 0.064%β-glucan group was higher. In addition, the growth performances of 0.064%β-glucan group were better after high dose challenged.