Interval mapping within 5 families of Japanese Black Cattle (Wagyu) to detect segregating QTL for birth weight and preweaning average daily gain on bovine chromosome 1 was performed by genotyping 132 half-sib progeny using 98 microsatellite DNA markers. A significant QTL for birth weight was detected at 114cM (95% confidence interval of 50-130.5cM) in one sire. Suggestive QTL for preweaning average daily gain were detected at 14cM and 18cM just below the chromosome-wide threshold in 2 sires. It was concluded that evidence of significant QTL in chromosomal regions of bovine chromosome one was compelling for birth weight hence enhancing the prospects of marker-assisted selection in this breed
