In Yiyang Swine Breeding Farm, age at 100kg of replacement pig in Duroc and Large White dropped 16.37 and 16.42 days respectively, population EBV dropped 2.69 and 2.57 days respectively.

• 2004年与2000年相比；益阳农科所种猪场杜洛克、大白后备猪达100kg体重日龄分别下降了16.；37、16