Pig Wean-to-Service Interval Welfare

The wean-to-service interval (WSI) in sows is a critical welfare indicator reflecting nutritional status, reproductive health, and management quality on pig farms.

Key Facts

WSI measures days between weaning and successful mating in sows - ideally 4-7 days
Extended WSI indicates negative energy balance, stress, or inadequate nutrition during lactation
Sows losing excessive body condition during lactation have prolonged WSI and poorer subsequent litter performance
Gilt management before first service significantly impacts lifetime reproductive welfare outcomes
Electronic sow feeding systems enable precision nutrition that supports optimal WSI

Welfare Considerations

WSI is both a production metric and a welfare indicator - prolonged intervals reflect sow stress and nutritional inadequacy during a physiologically demanding period. Lactation depletes body reserves; inadequate feeding during this period compromises both current welfare and subsequent reproductive success. Management approaches that maintain sow body condition through lactation, using individual feeding systems and appropriate diet formulation, protect both welfare and reproductive performance.

What You Can Do

Support farms using electronic individual sow feeding systems that monitor body condition
Advocate for WSI monitoring as a welfare indicator in sow management standards
Learn about the relationship between sow nutrition and welfare in pig production
Choose pork from farms with independently verified sow welfare management protocols