体外产气法评价南方经济作物副产物对肉牛的营养价值

Assessment of nutritional value of southern economic crops byproducts on beef cattle by gas production method in vitro

试验主要利用体外产气法估测包括桑叶、麻叶在内的15种南方经济作物副产物对肉牛饲用的营养价值。通过体外发酵试验并采用批次培养法,将15种参试样品培养120 h,在培养过程中分别记录0、2、4、6、8、10、12、16、20、24、30、36、42、48、60、72、84、96、120 h各个时间点的产气量,并测定发酵24、48 h时发酵液的挥发性脂肪酸（VFA）产量、氨态氮（NH3-N）的浓度、p H值以及体外干物质消化率。由各个时间点的产气量情况来看,各种参试样品的产气量均随时间先逐渐升高最后趋于平衡,其中柑橘渣在各个时间点的产气量以及总产气量（66.41 ml）均显著高于其他原料（P〈0.01）;笋壳、玉米壳以及柑橘渣24 h及48 h时的挥发性脂肪酸含量明显高于其他原料（P〈0.01）,而乙酸/丙酸最高的是红苕藤（P〈0.05）。在24 h及48 h两个时间点发酵液中氨态氮（NH3-N）浓度最高的均为红苕藤,差异显著（P〈0.05）;通过对两个时间点p H值的测定,发现培养过程中发酵液的p H值保持相对恒定在6.7~6.9之间。柑橘渣的体外干物质消化率在两个时间点分别以56.18%和62.42%保持最高,其次是红苕藤和花生藤。在本试验条件下,数据统计分析表明,柑橘渣、桑叶、花生藤、红苕藤、笋壳、玉米壳、象草等原料均可以通过加工利用作为新型饲料资源加以开发利用,而麻叶、甘蔗渣、油菜秸秆的利用则需要进一步的研究。

Abstract：This experiment estimate the nutritive value on beef cattle of 15 southern economic crops by- products including mulberry leaves, sesame leaves by gas production method in vitro. With the method in vitro and implement the experiment in batch, the gas production were recorded at Oh, 2, 4, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48, 60, 72, 84, 96 h and 120 h, respectively. The fermented fluid was col- lected at 24 h and 48 h to determine the concentration of NH3-N, VFA, pH and the IVDMD after fer- mentation. Aecording to the gas production of the different test materials in each time, the gas produc- tion were increased gradually with time at first and finally tends to balance .The gas production of each point time also the total gas production （66.41 ml） of Citrus pulp were significantly higher than those of other materials （P〈0.01）; T24H he concentration of volatile fatty acids of bamboo shoot shell,corn husks and citrus pulp at 24 h and 48 h were significantly higher than those of other ma- terials （P〈0.01）, and acetic acid/ propionic acid at 24 h and 48 h of Ipomoea batatas vine is the highest （P〈0.05）. The concentrations of Ammo- nia nitrogen（NH3-N） of Ipomoea batatas vine at 24h and 48h in the fermentation fluid were sig-nificantly highest （P〈0.05）; On basis of the measurement of pH at the two time points, the pH in the process of fermentation remained relatively constant at 6.7-6.9. Dry matter degradability in vitro of Cit- rus pulp at two time points respectively to 56.18% and 62.42% to maintain the highest, which were fol- lowed by Ipomoea batatas vines and peanut vine. The statistical analysis of the data under the condi- tions of this experiment showed that, citrus pulp, mulberry leaves, peanut vine, Ipomoea batatas vine, bamboo shoot shell, corn husks, napier grass and some other test materials can be processed to be de- veloped and utilized as a new feed resources, and the use of Sesame leaves, Bagasse, Rape straw needs to be further studied.