LINE-OF-MALE EFFECTS ON LIFETIME PERFORMANCE IN MICE

Abstract

Six straight-bred lines of mice were used both as straight-bred (STR) lines and to set up five crisscross (CC) lines (classes) and five repeat hybrid male cross (RHMC) lines, (classes). Females in each line were pair-mated with either males of the same line (group I) or males from a synthetic line (group II). Pairs were maintained for up to 155 days after mating (lifetime). Data from six generations were analyzed to examine differences between group I and group II in lifetime performance for each line in each generation. Line-of-male effects for the above difference (group I–Group II) expressed as a percentage of the average of group I and group II means were, under CC, RHMC and STR, −11, +5 and −2 for number of parturitions during 155 days, −12, +3, and −7 for total number of young born alive, −12, + 2 and −8 for total weight of young born alive, −12, +3 and −8 for total number of young at weaning, −11, +2 and −8 for total weight of young at weaning and −8, +3 and −1 for actual days of reproductive life, respectively. Lifetime performance of females differed depending on males used for mating, and F1 males were superior to males from the synthetic line which excelled males from straight-bred lines. Key words: Male, lifetime performance, reproduction, mice