轮牧方式对荒漠草原滩羊牧食特征、体重及繁殖性能的影响

发布时间：2019-02-15 23:21

【摘要】：【目的】合理的放牧方式对维持草地生态系统平衡具有重要意义。研究轮牧方式对滩羊牧食特性、体重及繁殖性能的影响可为草地放牧管理提供依据。【方法】以宁夏面积最大的荒漠草原为对象,在载畜率为0.75只/hm2水平下,设置连续放牧(CG)、二区轮牧(TG)、四区轮牧(FG)、六区轮牧(SG)4个处理。采用跟群全天观察法测定滩羊的牧食习性,利用差额法测定采食量,采用常规方法测定草群和滩羊摄入牧草营养成分,每个轮牧周期结束观测滩羊的体重,统计放牧期间繁殖性能等。【结果】放牧全天,滩羊采食时间占据了主体,比例达64%以上。随轮牧分区增加,滩羊采食、游走站立时间下降(P0.05),反刍卧息时间增加(P0.05);排泄、争斗、瘙痒、啃食异物等其他行为受个体行为影响更大,所占时间比例不到1.4%。草地牧草采食量表现为四区与六区轮牧无明显差异(P0.05),但均高于连续放牧和二区轮牧,连续放牧采食量最低(P0.05);草地采食率呈现连续轮牧二区轮牧四区轮牧六区轮牧的趋势,连续放牧达到39.06%,六区轮牧仅为27.9%;滩羊日采食量在二区、四区、六区轮牧方式下差异不大(P0.05),在连续放牧区最低(P0.05)。滩羊摄入的牧草的粗蛋白、粗脂肪、磷的含量总体高于草群相应养分含量,而粗纤维和钙低于草群养分含量,粗灰分和无氮浸出物比较接近,说明滩羊具有选食蛋白质含量高,粗纤维含量低牧草的能力;随轮牧分区增加,滩羊摄入的牧草粗蛋白含量呈下降趋势、粗纤维呈上升变化,但滩羊摄入干物质、粗蛋白和磷的总量增加;各处理下滩羊营养摄入量均超出了美国NRC绵羊饲养标准,说明暖季滩羊放牧不需要补饲。放牧期间,滩羊体重和日增重以连续放牧最低(P0.05),二区、四区及六区轮牧间无显著差异(P0.05);各处理下滩羊产羔率、羔羊平均初生重等繁殖性能接近,说明在适宜载畜率水平下,轮牧方式对滩羊繁殖性能影响不大。【结论】轮牧方式对滩羊牧食特征和增重产生了影响,相对于连续放牧,随轮牧分区增加,草地牧草采食率、滩羊采食时间和摄入的牧草粗蛋白含量下降,但草地采食量,滩羊日采食量及摄入的干物质、粗蛋白等营养物质总量增加。划区轮牧没有提高滩羊繁殖性能,但更有利于滩羊体重增加。若仅考虑滩羊牧食特征、增重性能以及生产中放牧管理的便利性,二区轮牧方式是宁夏荒漠草原滩羊暖季的最优放牧方式。
[Abstract]:Objective: to maintain the balance of grassland ecosystem with reasonable grazing methods. The effects of rotation grazing mode on grazing characteristics, body weight and reproductive performance of Tan sheep could provide basis for grazing management of grassland. [methods] taking the desert steppe with the largest area in Ningxia as an object, the stocking rate was 0. 75 / hm2. Four treatments were set up for continuous grazing, rotation grazing, (TG), (FG), (FG), six, continuous grazing. The grazing habits of Tan sheep were measured by the whole day observation method, the feed intake was measured by the difference method, and the forage nutrients were measured by the conventional method. The body weight of the Tan sheep was observed at the end of each cycle of grazing. [results] the feeding time of Tan sheep occupied the main part in the whole day of grazing, and the proportion was more than 64%. With the increase of rotation grazing, the feeding time of Tan sheep decreased (P0.05), and the time of regurgitation increased (P0.05). Other behaviors, such as excretion, fighting, itching, and eating foreign bodies, are more affected by individual behavior, accounting for less than 1.4 percent of the time. There was no significant difference in grazing intake between four and six regions (P0.05), but it was higher than that of continuous grazing and rotation grazing in the second area (P0.05), and the feed intake of continuous grazing was the lowest (P0.05). The grazing rate of grassland showed the trend of rotation grazing in the fourth and sixth districts of the second district of continuous rotation grazing, and 39.06% of continuous grazing, and only 27.9% of rotational grazing in the six regions. The daily feed intake of Tan sheep in the second, fourth and sixth districts had little difference (P0.05), but the lowest in the continuous grazing area (P0.05). The content of crude protein, crude fat and phosphorus was higher in Tan sheep than that in grass group, but the content of crude fiber and calcium was lower than that of grass group, and the crude ash content and nitrogen free extract were close, which indicated that Tan sheep had high protein content of selective feed, but the content of crude fiber and calcium was lower than that of grass group, and the crude ash content was close to that of nitrogen free extract. The ability of low fiber content forage; With the increase of rotation grazing area, the content of crude protein and crude fiber of Tan sheep decreased, but the total intake of dry matter, crude protein and phosphorus increased. The nutrient intake of Tan sheep under each treatment was higher than that of American NRC sheep, which indicated that there was no need for supplementary feeding of Tan sheep in warm season. During grazing period, the weight and daily gain of Tan sheep were the lowest in continuous grazing (P0.05), but there was no significant difference between rotation grazing in two, four and six districts (P0.05). The lambing rate and the average birth weight of lambs under different treatments were close to each other, which indicated that the rotation mode had little effect on the breeding performance of Tan sheep at the level of suitable stocking rate. [conclusion] the rotation mode had an effect on the feeding characteristics and weight gain of Tan sheep. Compared with continuous grazing, with the increase of rotation grazing, the forage intake rate, the intake time and the content of crude protein of forage decreased, but the intake of grassland, daily intake and dry matter of Tan sheep decreased. The total amount of nutrients such as crude protein increased. The rotation grazing did not improve the breeding performance of Tan sheep, but was more favorable to the weight gain of Tan sheep. If only the feeding characteristics of Tan sheep, the performance of weight gain and the convenience of grazing management in production were taken into account, the optimal grazing mode of Tan sheep in Ningxia desert steppe in warm season was the rotation mode of grazing in the second area.
【作者单位】：宁夏大学农学院草业科学研究所;宁夏大学西北土地退化与生态恢复国家重点实验室培育基地;
【基金】：国家重点研发计划课题(2016YFC0500505) 宁夏回族自治区科技支撑重大专项(2012) 中国科学院“西部之光”人才培养引进计划项目(XAB2015A10)
【分类号】：S826;S812.8

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