Cross-Fostering Implications for Pig Mortality, Welfare and Performance

Area of Science:

• Animal Science
• Veterinary Medicine
• Agricultural Science

Background:

• Cross-fostering (CF) is a common practice in commercial pig farming.
• Understanding the implications of CF on pig health, welfare, and performance is crucial for optimizing production.

Purpose of the Study:

• To identify cross-fostering practices on a commercial farm.
• To characterize cross-fostered pigs based on litter of origin traits.
• To investigate the effects of CF on pig mortality, performance, and welfare.

Main Methods:

• An observational study involving 1,016 pigs, classified as non-CF (NCF), CF during the first week (CFW1), or later weeks (CFW2+).
• Pigs were weighed and inspected for lesions at multiple stages, with mortality recorded through to slaughter.
• A nested case-control design was used to analyze associations between CF timing, welfare, and performance traits.

Main Results:

• Cross-fostered pigs (CF) exhibited a higher risk of mortality compared to non-CF pigs.
• Growth performance did not significantly differ between CF groups, but CFW2+ pigs had lighter carcasses at slaughter.
• Ear lesions were more prevalent in CFW1 pigs compared to NCF and CFW2+ pigs.

Conclusions:

• Cross-fostering practices are associated with increased mortality risk in pigs.
• While overall growth performance may not be affected, CF timing can influence carcass weight and the incidence of specific welfare indicators like ear lesions.
• The mechanisms linking early cross-fostering to ear lesions require further investigation.