中国北方草原草畜代谢能平衡分析与对策研究

摘要

Feed balance is the prerequisite of the sustainability of grassland animal husbandry.The techniques of monitoring and evaluation of feed balance is the base of achieving sustainability on this matter.The paper is to discus the techniques used in the study to evaluate and to monitory the feed balance,of which the metabolic en-ergy(ME) of sheep requirement and of grassland supervision in a year around were used as the benchmark to understand the feed balance status of the typical farm in Sunan County of Gansu province,in addition,supplementation strategy was worked out in according with the feed balance status of the typical farms of the pilot farm in this study.The results showed ME provision from grassland was higher than animal maintenance requirement in warm season from June to October,consequently,the body weight of sheep increased significantly.The ME provision was in deficit in cold season from November to May,as the results,the body weight losses was significant during this period of time.The stocking rate was the highest in summer pasture among 3 pasture types which were summer pasture,winter pasture and spring and autumn pasture.The results also showed the ME requirement of sheep fed in warm shed in winter was lower than those in conventional yard which should be an alternative in relieving ME deficit in winter and benefit in feed balance too.Experiment was designed to test the ewes were fed in warm shed in winter,the results showed the wool yield of experimental sheep was 0.73 kg/head higher than those of controls,the body weight loss decreased 14.9%,and pure income increased 126.25 Yuan/head respectively.The study also demonstrated that the lambing time had large effect on feed balance.Under the range of the production practice,the delaying lambing time can improve feed balance.The research measured lambs growth performance and the body condition of ewe which lambed in April and May.Result showed the birth weight of the lamb born in May and June were significantly higher than those born in April although the body weight of the lamb born in May was 4-5 kg lower than April lambs because of short growing time.However,the pen feed practice may be applied to achieve heavier body weight at the selling time of September.By conclusion,ME as the benchmark is a precise way in monitoring and evaluation of the feed balance status of the pasture animal husbandry,which at the end will ensure the process of achieving sustainability for pasture based animal husbandry in China/ In addition,better understanding of the feed balance status will also help technicians and farmers to alter the production practice so that supplementation strategies and management practice can be applied accordingly.%草畜平衡是天然草地可持续利用和放牧家畜高效生产的前提,草畜平衡评估技术是实现草原保护,提高草地畜牧业可持续发展的基础.本研究建立了以代谢能为指标的草畜平衡评价方法,2008年冬以甘肃肃南草原和典型牧户为研究对象,通过草畜代谢能平衡分析了草畜平衡现状,应用研究试验,验证了实现草畜平衡的优化途径和对策.草畜平衡分析结果表明,在牧草生长期(6月—10月)家畜获得的代谢能高于家畜的维持需要,因此,家畜体重增加,生长速度最快；在枯草期(11月一次年5月)代谢能摄入量低于维持需要量,家畜掉膘,体重下降,夏草场的载畜量最大.冬季暖棚舍饲养殖能够降低家畜的代谢能需要,有助于实现草畜平衡.与对照组相比,暖棚养殖绵羊平均产毛量显著提高(P＜0.05),提高了0.73 kg/只,冷季体重损失减少14.9％,纯收入增加126.25元/只.产羔时间对草畜平衡具显著的影响,适当推迟产羔时间能够有效的改善草畜平衡状况.分别测定了4月和5月所产羔羊的生长发育情况和母羊体况,5月羔羊平均初生重、1月龄、2月龄体重显著高于4月份羔羊(P＜0.05),但由于生长期短,5月羔羊出栏重较4月低4～5 kg.草畜代谢能平衡是分析研究草畜平衡的科学、合理和准确的方法和技术,草畜代谢能平衡分析模型的准确度高,适用性强,有利于草原管理,所提出的改善草畜平衡的途径和策略可行性高.