The decision to cull a sow from the breeding herd typically occurs after weaning due to poor lactation performance, lameness or if she fails to breed or conceive. Once the decision to cull a sow from the breeding herd has been made, a producer must decide to either immediately market the sow or to increase marketable body weight by feeding her for a period of time. The decision to feed cull sows to add additional body weight is not a simple decision. Many factors such as current cull sow market prices, available housing space, feed cost, and health of the animal contribute to this decision . Revenue from marketing cull sows contributes to the profitability of pork operations, therefore much care should be placed on deciding when to market cull sows.
U.S. Pork Center of Excellence
Fitzgerald, Robert F.; Stalder, Kenneth J.; and DeRouchey, Joel M., "Cull Sow Feeding Management" (2010). Animal Science White Papers, Technical Reports, & Fact Sheets. 10.