The largest data set consisted of 12847 records with 47 sires and 778 HYSs, which is corresponding to the milk yield data available currently in Beijing area.

• 4种数据结构中最大的有12847个观察值, 场年季效应和公牛效应水平数分别为778和47,它与北京市目前可利用的奶牛头胎产奶量记录资料相当。