2005. Reproductive success of broiler breeders in natural mating systems: The effect of male-male competition, sperm quality, and morphological characteristics. Poult. Sci

ABSTRACT In natural mating systems in which broiler breeder males compete for females, reproductive behav-ior plays an important role in male fertility, along with sperm competition and morphological and physiological characteristics. We investigated the effect of male-male competition compared with a noncompetitive situation on fertility, sperm quality, and morphological traits. Six groups of 3 males and 12 females were housed in mixed-sex pens. Their frequency of mating was recorded, and progeny of each male was determined through DNA fin-gerprinting.Maleswith the highest and the lowestmating frequencies were later placed into groups of 1 male and 4 females, their behavior was recorded, and their fertility was calculated. We collected data on semen quality (se-men volume, sperm concentration, and mobility) and morphometrical characters. Finally, females were artifi