Yang Guiqin, Zhao Fei, Tian He, Li Jiantao, Guo Dongxin
College of Animal Husbandry and Veterinary Medicine, Shenyang Agricultural University, Shenyang, Liaoning 110866, China.
Asian-Australas J Anim Sci. 2020 Apr;33(4):623-633. doi: 10.5713/ajas.19.0221. Epub 2019 Aug 3.
Substituting starch with digestible fiber (dF) can improve digestive health of rabbits and reduce costs. Therefore, it is necessary to develop a criterion for dF and starch supply. Effects of the dietary dF-to-starch ratio on pellet quality, growth and cecal microbiota of Angora rabbits were evaluated.
Five isoenergetic and isoproteic diets with increasing dF/starch ratios (0.59, 0.66, 0.71, 1.05, and 1.44) were formulated. A total of 120 Angora rabbits with an average live weight of 2.19 kg were randomly divided into five groups with four replicates. At the end of 40 day feeding trial, cecal digesta were collected to analyse microbiota.
The results showed that the dF/starch ratio had linear effects on pellet variables (p<0.01). When the dF/starch ratio was 1.44, the pellets had the lowest powder and highest durability. The dF/starch ratio had unfavorable linear effects on growth variables (p<0.001). When analyzed by quadratic regression, the optimal dF/starch ratios for average weight gain and feed/gain were 0.59 and 0.74, respectively. There were differences in wool yield, fiber length and fiber diameter caused by the dF/starch ratio (p<0.05), and the dF/starch ratios that ranged from 0.66 to 1.06 were appropriate for good results. The cecal microbiota operational taxonomic unit (OTU) number index in the 1.05 dF/starch treatment was higher than that in the 0.66 and 0.71 dF/starch treatments. The higher dF/starch ratio resulted in a higher cecal microbiota OTU number index (p<0.05). The proportion of Ruminococcus in the 0.71 dF/starch treatment was higher than that in the 0.59 dF/starch treatment (p<0.05).
The most suitable dF/starch ratio for feed pellet quality is 1.44, and for rabbit growth the optimal range of ratios is from 0.59 to 0.74. With combination of the wool growth, output cost, and cecal microbiota, we suggest that a dietary dF/starch ratio ranging from 0.74 to 1.06 is optimal.
用可消化纤维（dF）替代淀粉可改善家兔的消化健康并降低成本。因此，有必要制定dF和淀粉供应标准。评估了日粮中dF与淀粉比例对安哥拉兔颗粒质量、生长性能和盲肠微生物群的影响。
配制了5种等能量、等蛋白且dF/淀粉比例递增（0.59、0.66、0.71、1.05和1.44）的日粮。将120只平均体重为2.19 kg的安哥拉兔随机分为5组，每组4个重复。在40天的饲养试验结束时，收集盲肠内容物以分析微生物群。
结果表明，dF/淀粉比例对颗粒指标有线性影响（p<0.01）。当dF/淀粉比例为1.44时，颗粒的粉末含量最低，耐久性最高。dF/淀粉比例对生长指标有不利的线性影响（p<0.001）。通过二次回归分析，平均增重和料重比的最佳dF/淀粉比例分别为0.59和0.74。dF/淀粉比例对羊毛产量、纤维长度和纤维直径有影响（p<0.05），0.66至1.06的dF/淀粉比例有利于获得良好结果。1.05 dF/淀粉处理组的盲肠微生物群操作分类单元（OTU）数量指数高于0.66和0.71 dF/淀粉处理组。dF/淀粉比例越高，盲肠微生物群OTU数量指数越高（p<0.05）。0.71 dF/淀粉处理组的瘤胃球菌比例高于0.59 dF/淀粉处理组（p<0.05）。
饲料颗粒质量的最适dF/淀粉比例为1.44，家兔生长的最适比例范围为0.59至0.74。综合羊毛生长、产出成本和盲肠微生物群因素，建议日粮dF/淀粉比例为0.74至1.06最为适宜。
