2004 年 25 巻 1 号 p. 25-36
In this paper, a fast algorithm for computing inbreeding coefficients in large populations in which a list of ancestors for each animal is required is modified for more quick calculation. With the current algorithm, an efficient procedure to make the list of the ancestors is used, which is based on grouping the ancestors of each animal chronologically by the use of longest ancestral path. A simulation study is carried out to compare the computational properties of the presented algorithm with those of the original and another typical algorithms. It is found that the presented algorithm becomes considerably fast relative to the original one, as the average number of generations and the number of animals increase. It is also shown that the current algorithm takes less time than another typical algorithm compared, when less than 19 generations are evaluated. The results obtained clearly indicate that the current algorithm requires much less computer time and less memory than the original and another typical algorithms, respectively.