Changing livestock and grassland management to improve the sustainability and profitability of alpine grasslands in Sunan county, Gansu province

摘要

Grassland degeneration is a serious ecological and social problem in north-western China, and overgrazing is one of the most important reasons for degeneration. Overgrazing issues were assessed by first investigating the feed balance between forage and supplement supply versus animal demand. The effects on the feed balance of alternative management practices were investigated using StageONE and StageTWO models to assess ways of improving animal performance and identify opportunities to rehabilitate grasslands. This study was done for a typical farm in the town of Kangle in Sunan county, north-western Gansu. Analysis of the feed balance showed the metabolisable energy feed supply is typically grossly deficient from October to May because the quantityand energy content of the frosted forage is then very low. The peak of herbage production is in June, the highest maintenance requirement is from March to May and there is an excess of herbage above maintenance in summer grasslands, which enables animals to grow. Grazing in the cold season requires a great deal of energy to maintain body temperatures and for walking, and contributes to the -30% of live-weight loss that occurs through that period. Results were discussed with local herders and technicians, who considered that the modelling accurately reflected the local situation. The amounts of supplements fed through autumn, winter and spring are inadequate to maintain animal condition. A better alignment of feed supply and demand could be achieved bychanging the lambing time from April to June. Most households in Sunan have built warm sheds, but they are not well used. Modelling suggested that herders should pen feed ewes in warm sheds through the cold season, as that would lower maintenance requirements and aid better survival and growth of lambs. These practices are now being tested on five farms and the initial results support the model results. Better feeding through the cold weather increased costs and net income from livestock. Future on-farm work will investigate decreasing animal numbers by improving animal production efficiency using a new precision livestock management model.