不同放牧率和放牧时期绵羊粪便中各化学成分变化及与所食牧草各成分间的关系

THE INFLUENCE OF DIFFERENT STOCKING RATES AND GRAZING PERIODS ON THE CHEMICAL COMPONENTS IN FECES OF GRAZING SHEEP AND RELATIONSHIP AMONG THE FECAL COMPONENTS

实验结果表明：1．在同一放救时期内，绵羊粪中CP和EE的含量随放牧率的增大而减小；在同一放牧率下，以8月份的含量最高，6月份的与9月份的相差不大；但在重牧条件下，6月份EE的含量明显大于9月份的含量。粪中Ash和CF的含量，随不同放牧率和放牧时期的变化趋势正好与CP和EE含量的变化趋势相反；粪中NFE的含量变化不规律。2.绵羊粪中各成分间的关系可分为三种类型：（1）DM、Ash和CF；（2）CP和EE；（3）NFE。各类型内各成分间均呈显著或极显著正相关（P＜0．05或P＜0．01），前两个类型的各成分间均呈极显著负相关（P＜0．01），第三个类型（NFE）与前两个类型各成分间均相关不显著（P＞0．05）。3．绵羊粪便中化学成分与日粮中各营养成分间的相互关系见下图。

The experiment was conducted at Inner Mongolia Grassland Ecosystem Research Station in 1993. The results showed that: 1. Under the same grazing period, the contents ofcrude protein(CP) and ether extract(EE) in the feces of grazing sheep decreased with increase of the stocking rates; Under the same stocking rates, the contents of CP and EE werethe highest in August, and the content of the fecal CP in June and September's were notdifferent significantly, but the contents of EE in June were higher than September's underheavier stocking rates (5. 33 and 6. 67 sheep / hm2. 138days): the variation trends of thecontents of the fecal ash and crude fiber(CF) were just opposite with CP's and EE's under different grazing periods and stocking rates; the variation of the contents of the fecalN - free extract(NFE) were not regular under all conditions. 2. The relations of these fecalcomponents could be divided into three categories: ①DM. Ash and CF; ②CP and EE; ③NFE. The components of categories ① and ② were generally positively related (P < 0. 05or P < 0. 01) to other components in their respective categories and negatively related(P <0. 05 or P < 0. 01)to other category. There was no correlation(P > 0. 05) between the components of category ①、 ②and category ③； 3. The relationships between the fecal components and herbage components could be seen from the figure as follows.