Farmed Pig Mortality: Prevention and What Mortality Rates Tell Us

Pig mortality rates are a key welfare indicator in commercial production. Understanding what mortality data reveals — and what it hides — helps advocates and producers use it meaningfully.

Key Facts

Pre-weaning piglet mortality averages 10-15% in conventional systems, with crushing by the sow a leading cause
Post-weaning mortality from respiratory disease, enteric disease, and tail biting injuries is a significant welfare indicator
Very high or very low mortality rates can both indicate welfare problems — suppressed mortality through prophylactic antibiotics masks underlying issues
Dead-on-arrival (DOA) rates at slaughter reflect transport welfare and are a mandatory-reporting welfare indicator in some jurisdictions
On-farm euthanasia quality — whether animals are killed humanely and promptly — is itself a welfare indicator often not captured in mortality data
Farms with high positive welfare indicators (enrichment, low stress) consistently show lower mortality alongside better welfare scores

Welfare Considerations

Pig mortality data is one of the most widely available welfare indicators in commercial pig production but must be interpreted carefully. Raw mortality percentage tells only part of the welfare story: a farm with low mortality achieved through prophylactic antibiotic use that suppresses disease pressure in overcrowded conditions has a different welfare profile than a farm with equally low mortality achieved through low density and good stockmanship. Conversely, some mortality is inevitable and the welfare question is whether animals that do die do so quickly and humanely or slowly and suffering. The most welfare-informative use of mortality data involves tracking trends within farms over time, comparing against benchmarks for similar systems, and combining mortality indicators with positive welfare measures that capture the quality of life of surviving animals. Promoting the use of mortality data as one input in a comprehensive welfare assessment, rather than as a standalone metric, produces more accurate welfare understanding.

What You Can Do

Support farm assurance schemes that include mortality rate thresholds as welfare criteria within a broader indicator set
Advocate for mandatory reporting of on-farm mortality data as a transparency and accountability measure
Support research into what different mortality patterns reveal about underlying welfare conditions in pig farms
Ask food companies about how they use mortality data from their supply chains to identify and address welfare problems
Promote understanding that very low mortality is not automatically evidence of good welfare — context and causation matter