Japanese quail (Coturnix japonica) is an important model animal in poultry studies. In the present study a large F2-cross design to map QTL for PU and other correlated traits on 14 chromosomes was used. Next to PU, the traits calcium utilization, body weight gain, and feed per gain ratio were investigated. Because the marker density was only sparse, QTL linkage interval mapping was performed. A line cross model and a paternal half-sib model was applied. Both models revealed several QTL for the traits investigated. In the line cross model QTL were identified on CJA04, CJA09 and CJA10. The dominance effect was important for the calcium utilization QTL on CJA04 and CJA09 and imprinting was important for the calcium utilization and PU QTL on CJA04 as well as for the PU QTL on CJA10. In the paternal half-sib model, QTL were identified on CJA1, CJA14, CJA17 and CJA20. There was no overlap in detected QTL between the models. A likely explanation is the different assumption made by the two models.