不同NDF与淀粉比例饲粮在奶牛瘤胃的降解特性

Rumen degradation characteristics of different neutral detergent fiber / starch ratio diets in dairy cattle

本研究旨在探讨不同中性洗涤纤维（NDF）与淀粉（Starch）比例饲粮在奶牛瘤胃的降解特性。选用青贮玉米（Zea mays）、燕麦（Avena sativa）干草和玉米籽粒调整饲粮中性洗涤纤维和淀粉比例,配制0.86（Ⅰ）、1.13（Ⅱ）、1.56（Ⅲ）和2.38（Ⅳ）4种全混合日粮,以体况良好、平均体重为（600±21）kg且安装永久性瘤胃瘘管的3头荷斯坦奶牛为试验动物,通过尼龙袋法对4种饲粮的干物质（DM）、有机物（OM）、粗蛋白质（CP）、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）瘤胃降解参数和有效降解率进行评定。饲料样品在瘤胃内的培养时间分别为2、4、8、16、24、36、48和72 h。结果表明,不同中性洗涤纤维与淀粉比例的日粮常规营养成分存在差异。4种日粮的DM、OM、CP、NDF和ADF瘤胃有效降解率之间存在差异,其高低顺序分别为Ⅰ组〉Ⅱ组〉Ⅲ组〉Ⅳ组、Ⅰ组〉Ⅱ组〉Ⅲ组〉Ⅳ组、Ⅱ组〉Ⅰ组〉Ⅳ组〉Ⅲ组、Ⅰ组〉Ⅱ组〉Ⅳ组〉Ⅲ组、Ⅰ组〉Ⅳ组〉Ⅲ组〉Ⅱ组。由此可见,从4组饲粮在奶牛瘤胃的消化特性来看,NDF与淀粉比例为0.86-1.13的营养价值较高,本研究结果为科学、合理地配制奶牛日粮从而有效利用饲料资源提供依据。

This experiment was conducted to evaluate the rumen degradation characteristics of four different neutral detergent fiber/starch ratio diets. Silage maize, oat grass and corn grain were used to adjust the NDF/Starch ratio. Four total mixed rations were fed with different NDF/Starch in ratios of 0.86（Ⅰ）,1.13 （Ⅱ）,1.56（Ⅲ） and 2.38（Ⅳ）, respectively. Three healthy Holstein cows in midlactation （600±21 kg body weight） with permanent ruminal cannulas were selected as experimental animals, and the rumen degradation rates of dry matter （DM）,organic matter （OM） ,crude protein （CP）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） of four rations were measured using nylon bag method. The culture time of rations in the rumen was 2, 4, 8, 16, 24, 36, 48 and 72 h, respectively. The results showed that differences were found in common nutritional components, and rumen effective degradability of DM, OM, CP, NDF and ADF among four different neutral detergent fiber/starch ratio diets. Ranking of the rumen effective degradability of DM, OM, CP, NDF and ADF among four diets from high to low was group Ⅰ〉Ⅱ〉Ⅲ〉Ⅳ, Ⅰ〉Ⅱ〉Ⅲ〉Ⅳ, Ⅱ〉Ⅰ〉Ⅳ〉Ⅲ,Ⅰ〉Ⅱ〉Ⅳ〉Ⅲ, respectively. In conclusion, in order to provide a basic parameters and theoretical foundation in formulating rations of dairy cows and use feed resources more effectively, ruminal degradation characteristics of rations are dissimilar, dietary ratio of NDF/Starch between 0.86 and 1.13, have the higher nutritive value among the four types of testing rations.