Semen production and fertility issues related to differences in genetic lines of boars

Boars have been reported to differ in various characteristics important to productivity of AI units. These aspects include sensitivity to seasonal infertility, ejaculate volume x age interactions, optimum collection frequency, discard (trash) rate of ejaculates, age of puberty, libido and trainability, and semen shelf life. In addition to differences among individual boars, there were also identifiable differences among breeds, between purebreds and crossbreds, and between lines. The percentage of ejaculates discarded varied among seasons and among breeds within season, with maternal purebred lines being the most sensitive to warmer temperatures. These same lines were also slower to mature and produced fewer sperm per ejaculate. Breeds differed in the sustainability of motility in stored extended semen, and in farrowing rates. Boar centers need to factor breed differences into their decision-making processes to ensure adequate boar power and customer satisfaction.