Date of this Version
Pedigree data from the American Simmental Association from 1986-2008 were used to analyze the pedigree structure and changes in generation intervals over time within the Simmental breed. The number of breeders that accounted for 10% of sires of sires (SS), sires of dams (SD), dams of sires (DS), and dams of dams (DD) were 3, 5, 5, and 16, respectively. States with the greatest influenceon the four pathways of selection (SS, SD, DS, and DD) included Montana, South Dakota, Kansas, and Texas. In general, generation intervals for the four pathways decreased by year of birth over the time span of the data analyzed, albeit numerically slight. Averagegeneration intervals for sires and dams also decreased by year of birth, while animals increased slightly.