Impact of porcine respiratory disease complex on carcass weight and meatiness: quantitative insights from a mixed-model analysis.

Abstract

Background: Porcine respiratory disease complex (PRDC) significantly impacts the swine industry worldwide, leading to economic losses due to poor growth performance, reduced feed efficiency, higher medication costs, and adversely affecting pig welfare by causing clinical symptoms such as fever, cough, loss of appetite, lethargy, and dyspnea. Cranio-ventral pulmonary consolidation (CVPC) and pleuritis are the most frequent macroscopic lung lesions observed in PRDC and are indicators of decreased animal welfare. This study aimed to quantify the effects of CVPC and pleurisy on carcass weight, meatiness, and average daily carcass weight gain (ADCWG) in fattening pigs, thereby assessing their impact on both production and welfare. A total of 679 slaughtered pigs from seven batches (farms) were evaluated for lung lesions at slaughter. We employed a mixed-model analysis to assess the correlation between lung lesions and production parameters across the farms.

Results: The mean prevalence of lesions was 23.86% for CVPC and 15.46% for pleurisy, indicating a significant presence of respiratory disease affecting animal welfare. Pigs with severe lung lesions (≥ 15.1%) exhibited significantly lower ADCWG compared to pigs without lesions (0.951 kg/day vs. 0.997 kg/day, p = 0.024), reflecting reduced growth performance and welfare. The mixed-effects model revealed that lesions in the right apical lobe and dorso-caudal pleurisy were associated with significant reductions in carcass weight (- 2.77 kg and - 2.29 kg, respectively) and carcass meat (- 1.76 kg and - 1.43 kg, respectively). An economic analysis under average market price conditions demonstrated that severe lung lesions could lead to financial losses of up to 11.53 EUR per 100 kg of meat, emphasizing the economic impact of compromised welfare due to respiratory diseases.

Conclusions: This study provides quantitative evidence of the negative impact of CVPC and pleurisy on carcass weight and meatiness in fattening pigs. The findings underscore the importance of effective respiratory disease management in swine production, highlighting potential areas for targeted interventions to improve animal health and economic outcomes.