动物模型及多性状BLUP在家禽遗传鉴定中的应用

利用最佳线性无偏预测法(BLUP)估计家畜的育种值,目前除家禽外已在其它各家畜中得到了广泛的应用。本文利用动物模型和多性状BLUP对“京白Ⅰ系”蛋鸡在1986—1987年24个家系的777个个体的系统分组资料进行了分析,估计出了所有个体的复合育种值。其中考虑了两个性状(40周产蛋数和36周蛋重)和两个固定效应(鸡舍-鸡笼效应和孵化批次效应)。同时还对混合模型方程组维数较大时如何在微机上实现进行了研究,即(1)利用磁盘存取系数矩阵的非零元素和中间计算结果;(2)简化了多性状BLUP的计算,利用乔列斯基(Cholesky)分解变换后,此法建立的方程数是常规算法方程数的1/q(q为性状数);(3)简化了方程组迭代求解的方法,即利用块迭代法,这样大大缩短了计算的机吋,节省了费用,使BLUP在家禽中的推广应用成为可能。

Animal Model and Multiple Trait BLUP Applied in Poultry Genetic Evaluation

Best linear unbiased prediction (BLUP) is a powerful method 10 estimate genetic values of animals,and is widely applied in many animal species but poultry.Beijing White Leghorn nested' data in 1986-1987 with 777 individuals were analysed by animal model and multiple trait BLUP.Two traits (40-week tegg production and 36-week egg weight) and two fixed effects (house-pen effect and.hatching-batch effect) were considered-The way to calculate a large sei of mixed model equations in micro-computer was studied.Only non-zero elements of the coefficient matrix of MME were stored on a disk.The iteration process was reduced by block iteration.It also simpfified the multiple tlrait BLUP method,the dimension of equations is only 1/q (q is the number of traits) of regular method.So it saved a lot of compute time and cost,and BLUP became applicable in poultry.The significance cf using BLUP in poultry are:(1) Eliminating-some fixed;,effects; (2) Reducing the estimation error for unbalanced data; (3) Estimating breeding values of progeny,'so we can shorten the generation interval; (4) It can estimate breeding values of individuals without records from the relatives' information; (5) The breeding value of sires and dams can be esHmated from their progeny records,used for family selection; (6) Due to genetic and environmental correlation between traits and all relatives information were considered,it can increase the selection accuracy.