adult fema hog which has been bred

例句：

1. 1. The farm has a large herd of adult female pigs.
   农场有一大群成年雌性猪。
2. 2. The farmer breeds these pigs for meat production.
   这位农民饲养这些猪是为了肉制品生产。
3. 3. The adult female pigs are kept in pens to prevent them from mating.
   成年雌性猪被关在围栏里，以防它们交配。