By using sire and dam lines that differ completely in breed composition maximum paternal, maternal and individual heterosis will be achieved. A terminal crossbreeding system also allows the producer to have maximum consistency in the final product, uniformity of production practices and less labor in the breeding barn. The problem in a terminal crossbreeding program is obtaining replacement gilts. There are two options. They can be purchased or raised on the farm.
Producers decide to purchase gilts for many reasons.
The greatest advantage to many producers is the opportunity to purchase animals of greater genetic value from a higher quality selection program. For other producers herd size may be too small to maintain a separate breeding group to produce gilts. For some, the only way to obtain some breeds or lines is by purchasing the terminal breeding animals. For other producers, using a single seedstock supplier that has high herd health can allow the establishment of a herd health level equal to that experienced by the supplier. Service generally means that gilts are purchased with a guarantee that they will breed, be available when needed and will be delivered to the farm.