Simple Summary
The shift from antibiotic-based (AB) to antibiotic-free (ABF) broiler production is an important change in poultry farming that may affect animal health and processing outcomes. This study analyzed data from 260 farms in Thailand to determine whether this transition influenced the rate of carcass condemnation. The results showed that condemnation rates increased slightly during the early stage of ABF implementation but later declined, with no overall significant impact of the transition. These temporary changes likely reflect short-term adjustment challenges, while later stabilization suggests improvements in farm management, biosecurity, and alternative health strategies. Although company-wide adaptive management measures were introduced during this transition, their specific effects were not directly evaluated. Overall, the findings indicate that moving to antibiotic-free production can be achieved without negatively affecting condemnation rates.
Abstract
The transition from antibiotic-based (AB) to antibiotic-free (ABF) broiler production represents a major shift in poultry management, with potential implications for flock health, welfare, and processing outcomes. This study evaluated its impact on condemnation percentage (%condemnation) using Bayesian structural time-series (BSTS) analysis. Data from a Thai integrator comprised 105,899 truckload-level records (2015–2020) across 260 contract farms. The AB period (2015–2017) served as the baseline, and the ABF period (2018–2020) was assessed using counterfactual projections. Time-series decomposition and change-point analysis revealed an increasing trend in %condemnation during the early phase of ABF implementation, followed by a decline in 2020, with five structural shifts detected. The BSTS model estimated an absolute effect of +1.10% (95% CI: −1.50 to 3.80; p = 0.207) and a relative effect of +95% (95% CI: −38% to 657%), indicating no statistically significant causal impact. The transient increase may reflect short-term adaptation challenges, whereas subsequent stabilization may be associated with adaptation to ABF production and other concurrent management changes. Overall, the transition from AB to ABF production did not significantly affect %condemnation. Adaptive management measures were implemented as a company-wide policy but were not directly evaluated within the BSTS framework.