Quantitative trait loci affecting milk yield, health, and type traits werestudied for seven large U.S. Holstein grandsire families using the granddaughterdesign. Seventy microsatellite markers located throughout the genome wereselected for the quantitative trait loci scan. Effects of marker alleles wereanalyzed for 30 traits (21 type traits, 5 milk traits, 2 calving ease triats,and somatic cell score and productive life) and 16 canonical traits derived fromtype and production traits. Previously we reported results from 36 of thesemarkers but have re-evaluated those results using a more robust analysis method.We report results from all 70 markers using permutation tests to calculateexperiment-wise significance values, replacing the less stringentcomparison-wise values previously reported. With this new methodology wedetected 9 putative quantitative trait loci within specific families. Fourmarkers were associated with effects on type traits on chromosomes 4, 5, 14, and23. Two markers were associated with effects on protein percentage onchromosomes 6 and 14, and 3 markers were associated with effects on productivelife on chromosomes 2, 21, and 23. Although these initial 70 microsatellitemarkers have been completed in the 7 Holstein families, additional markers willneed to be added to allow interval analysis of areas where putative QTL havebeen identified and to increase marker density where needed.