Study on effect of selective breeding to terminal nale duroc new line

Duroc was selected and bred using the method of combination with close and open breeding and composed base population . Daily gain and lean meat percentage of the base population were major selective traits by the results of productive performance testing . After five years selecting , male daily gain was 856 g , famale daily gain was 833 g and increased 6.87% , 5.98 % respectively ; male lean meat percentage reached 66.2% , famale lean meat percentage reached 65.6% and progressed 2.32 % , 2.66 % respectively ; the swine's backfat thickness reduced 0.8 mm , 0.6 mm respectively .