北京迪卡猪核心群育种方案优化研究——群体规模及选择强度

STUDIES ON OPTIMUM BREEDING SCHEMES IN BEIJING DEKALB PIG ——POPULATION SIZE AND SELECTION INTENSITIES

应用确定性模型考察群体规模对北京迪卡猪核心群公猪系育种成本、育种产出、育种效益及近交系数的影响。母猪规模为６０、８０、１００、１２０四个水平，公猪头数为６、８、１０、１２四个水平。种畜的选择是基于多性状综合选择指数进行，应用基因流动法计算育种产出。结果表明，增加母猪规模，有利于提高公母猪选择强度，从而加大育种产出，同时单位母猪育种成本下降，促进了育种效益的改善；公猪头数越少，公猪选择强度越大，育种进展也越高，但同时促进了群体近交速度。

A deterministic model was used to investigate the effects of population size on the breeding cost,output as well as breeding profit for the boar lines of Beijing Dekalb pigs There are 4 alternatives for number of sows(60,80,100,120)and boars(6,8,10,12),respectively The selection is based on multi trait total selection index,and the genetic gains are calculated with gene flow method(Hill,1974) The results show that:increasing the sow number helps to increase the selection intensities for replacements and then the breeding output Meanwhile,the average breeding cost per unit reduce when the number of sows goes up These result in a better breeding profit The less number of boars selected per year,the more efficient for the breeding scheme But in order to restrict the inbreeding rate,it is necessary to keep a mild number of boars The optimum number of boars is 8