人工草地绵羊放牧系统草畜供求关系的优化

Optimization of Forage Supply一Demand Relationship within Sheep Grazing System on Sown Pasture

在牧草平均生长量及其生长模式、基础母羊载畜量相同的前提下，以年生产周期为时间单元，以产羔时间的选择为主要手段，对人工草地绵羊放牧系统进行了逐步的总体优化设计和实验监测对比。逐步优化以后的产春羔设计系统与原产冬羔的生产系统相比，草畜供求的季节匹配趋于合理，全年供求趋于平衡；每个羊单位的冬季补饲成本可以由４３．４６元下降到１２．０８元；草地产出利润可由７４５元／ｈｍ￣２提高到１４１３元／ｈｍ￣２。优化后的实验监测系统与原生产系统相比，双羔率由２３％提高到４７％，繁殖成活率由８９％提高到１１６％。

A feeding scherne in relation to annual planning and monitormg a sheep grazing system on sown pas-tures in Guizhou province was designed on the base of average annual pasture growth,forage compositionand stocking rate of breeding ewes.Sheep prod uction was optimized by adjusting lambing time within thescheme for a better seasonal feed balance through the preduction cycle. It was shown that the cost of sup-plementary feeding per ewe through the winter decreased from RMB 43.46 Yuan to RMB 12.08 Yuan inthe new scheme(spring lambing)compared with the original system(winter lambing);the profit gain perbectare increased from RMB 745 Yuan to RMB 1 4 1 3 Yuan;the rate of twin lambs increased from 23%to47%and the rate of weaning survival increased from 89%to 11 6%.