肃南鹿场甘肃马鹿生产性能研究

1999-2001年调查了肃南鹿场甘肃马鹿的基本情况。甘肃马鹿的鲜茸产量随鹿龄增长分为,产茸量快速增加阶段(1～6岁)、产茸量缓慢增加阶段(6～11岁)和产茸量下降阶段(11岁以后)。总体上呈凸抛物线变化,11岁达到产茸高峰,鲜茸产量与体重,饲养群数量与鹿茸总产量极显著正相关(P<0.01)。甘肃马鹿体型在我国8个马鹿亚种中属中等偏下,幼鹿的体长指数和头长指数低于成年鹿,肢长指数和管围指数高于成年鹿,幼公鹿的胸围指数和体躯指数高于成年公鹿,但幼母鹿则低于成年母鹿,成年鹿体尺指数的性别差异大于幼鹿。1999和2000年适龄母鹿的繁殖率和繁殖成活率平均分别为61.5%和55.6%,母鹿繁殖率在3～5岁间逐渐增加,5岁马鹿最高,此后随着年龄的增加总体上呈下降趋势,但6～9岁之间下降幅度较小,意外伤害和疾病是影响繁殖成活率的两大因素。甘肃马鹿饲养群结构基本呈正金字塔型,不合理出售是甘肃马鹿饲养群性比和年龄结构失调的主要因素。甘肃马鹿的性比结构与鹿茸价格有正相关联系,性比的变化周期在8年左右,可以用作鹿茸市场预测。公鹿在6岁以前体重随年龄呈指数增加,1岁公鹿的体重可达60kg左右,屠宰后产出/投入为4.26,具有发展成为肉用型家畜的潜力。肃南鹿场高山草原-甘肃马鹿生产系统通过完善生产层次,经济效益提高3.

Impact of Organic Vegetable Production System in Kiambu and Kajiado Counties of Kenya

Though there are many documented reasons that make farmers to adopt organic farming system, economic benefits present a major motivation. The study was conducted to evaluate the impact of organic production system on profitability of smallholder vegetable production systems in the two counties so as to appraise its contribution to improvement of rural livelihoods. The study collected data on costs and returns for a sample of 208 smallholder vegetable farmers who were composed of 78 organic and 130 conventional farmers. Impact of organic production system was evaluated using propensity score matching technique. Organic vegetable production system was found to have a positive significant impact of increasing farm gross margin by US$0.58 representing 89.5% among smallholder producers in Kiambu and Kajiado Counties of Kenya. The study recommended promotion of organic production system as a tool that can be used to improve livelihoods especially in the rural areas.