Processing Optimization Research On The Seasonal Balance Of Supply And Demand In YunGui Plateau Sown Pasture Sheep Grazing System

On the basis of collecting natural resources, ecological and productive condition in the study site and under the guidance of grazing-ecological theory, index system of seasonal feed balance in sheep grazing system was established by applying computational supporting system. After analyzing problems in the management of the sheep grazing system about seasonal feed balance, Optimum schema was put forward, further it was actualized. Through comparing standard indicator value with indicator value in process optimum stage, information of seasonal feed balance was feedback. Optimum schema was modified and further optimized, and then indicator value of seasonal feed balance was monitored. Feed budget, the date of lambing and weaning change, stocking rate adjustment, conservation and supplement, seasonal fatten livestock(cattle), fertilizer application, rotation grazing policy, grazing in order and their different organization were used in the process of optimization to increase pasture and livestock production and improve inversion rate of livestock, The optimum results indicated that indicator value of monitor was as the same as or bigger than standard indicator value. The results show: (1 )Fertilizer application in early spring and late autumn increased pasture production from 6378kgDM/hm2 in no optimum stage to 7l66kgDMIhm2, and to 8281 kgDM/hm2 in monthly optimum stage. (2)By shifting pasture from growth season to winter time in low cost way 2 (conservation hay as well as the transfer of pasture cover), supplements should be fed in late winter and early spring to try and keep stock of pasture until a minimum pasture cover was reached. It was shown that the cost of supplementary feeding per SU (sheep unit) through the winter decreased from RMB 43.46 Yuan in no optimum stage to RMB 12.08 Yuan in yearly optimum stage, even to zero in monthly stage. (3)Changing lambing date(from winter to spring)decreased the supplement cost. At the same time, lambing rate increased over 31%, the rate of twin lambs increased about 35% and the survival rate after weaning increased about 40%. (4)Through purchase and sale animals stocking rate of the livestock system was adjusted according to seasonal pasture supply. Basic stocking was 7.5SU/hm2 at the end of year, 15 SU/hm2 in summer and autumn. The rate of sale livestock increased to 36?6%(including sale fatten cattle). The ratio of input to output was 1 .5--3 times at no optimum stage. (5)Rotation grazing policy and grazing animal in order kept livestock intake and pasture cover in standard indicator value. Pasture utilization ratio increased from 30%-.-45% to 70%?5%.