Farm Animal Welfare

Pig Wean-to-Service Interval and Sow Welfare

The wean-to-service interval in sows reflects their nutritional and physiological status after lactation, and managing this period well improves both reproductive performance and welfare.

Key Facts

Sows lose body condition during lactation due to the energy demands of milk production
Thin sows (BCS below 2 at weaning) have delayed return to oestrus and reduced litter sizes
Increased feed intake during late lactation reduces body condition loss
The wean-to-service interval is extended in sows with poor nutritional status
Short intervals of 4-7 days indicate good sow welfare and nutritional management

Welfare Considerations

The wean-to-service interval is a sensitive indicator of sow welfare during lactation. Extended intervals indicate that sows have been nutritionally depleted by the demands of lactation in combination with feed intake limitations. Good management of lactation nutrition - maximising feed intake, providing high-quality rations and minimising environmental stress - maintains sow condition and welfare throughout the reproductive cycle.

What You Can Do

Support farms with proactive sow lactation nutrition management
Advocate for sow body condition scoring as a routine welfare audit metric
Choose pork from farms demonstrating good sow welfare records