Multivariate Analysis of Hematological Stress Biomarkers and Welfare Domains in Organic and Intensive Pig Farming in Italy: A Pilot Study

Consumers are increasingly favoring ethically produced animal products due to concerns about animal welfare and farming practices. Pigs raised in intensive systems are often exposed to stressors that may affect their health, whereas organic farming is expected to offer better welfare conditions. However, evidence linking on‐site welfare assessments to physiological stress markers remains limited in pigs. This study aims to fill this gap and to compare welfare in organic and intensive farms through field evaluations and laboratory analyses. Four intensive farms and one organic farm were assessed using ClassyFarm, a system introduced by the Italian Ministry of Health in 2019, which evaluates farms through a structured checklist. Hematological and serum stress biomarkers were measured in 21 pigs from intensive farms and 22 from the organic farm. Data were analyzed using factor analysis and linear mixed models to explore correlations between ClassyFarm scores and physiological biomarkers. Welfare‐related biomarker levels were also compared between the farming systems. ClassyFarm results showed good welfare standards across all farms, though critical issues were observed in intensive systems. Conversely, the organic farm achieved optimal scores in all areas. Factor analysis grouped welfare indicators into five domains, displaying variable correlations with hematological markers, emphasizing the complex relationship between management, health, and welfare. Organic pigs showed improved immune responses, including higher leukocyte counts and complement activity, whereas pigs from intensive farms showed stress‐related immune alterations. The study confirms strong associations between ClassyFarm welfare scores and physiological biomarkers, suggesting that organic practices may enhance immune health and overall welfare.