Producer perceptions on the impacts of the withdrawal of zinc oxide on the health and welfare of weaned pigs.

Abstract

BACKGROUND: Zinc oxide (ZnO) added to pig feed at prophylactic levels has been used to reduce post-weaning diarrhoea (PWD) and enhance performance. In response to concerns about antimicrobial resistance (AMR) and environmental contamination, supplementation with ZnO was prohibited in the European Union from June 2022, and in the United Kingdom from June 2024. OBJECTIVE AND METHOD: We investigated the impacts of the withdrawal of ZnO on the health and welfare of weaned pigs as perceived by pig producers, and the management and husbandry factors associated with PWD in the United Kingdom. A mixed methods approach combined qualitative interviews with producers preparing to withdraw ZnO from their herds and a quantitative survey open to any producer. Findings were integrated using the transtheoretical model (TTM) of change as a guiding framework. RESULTS: Eight qualitative interviews and 14 quantitative surveys with producers were completed. Responses to the qualitative interviews were all from indoor, breeder-finisher herds while the quantitative survey included indoor and outdoor production systems and a mix of breeder-finisher herds and nursery units. In the qualitative interviews, producers described ZnO as affordable and effective. Concerns were expressed that its withdrawal risked triggering a sectoral increase in antimicrobial usage, jeopardising reductions achieved to date. The quantitative survey revealed that almost all respondents (12/14, 85%) had experienced PWD in their piglets in the last year. At the time of responding, 57% of respondents (8/14) reported weaner pigs were not fed a diet containing ZnO during the post-weaning period whereas 36% (5/14) were still feeding a diet containing ZnO. Following the withdrawal of ZnO in June 2024, most respondents (8/14, 57%) anticipated supplementing weaner diets with an alternative to ZnO before and after weaning. CONCLUSION: While recognising the limitations of a small sample size, the study contributes to our understanding of producer perceptions as they prepared for the withdrawal of ZnO. Producer concerns that PWD would be less effectively controlled in their herds and risked triggering an increase in antimicrobial usage were highlighted. Further work is required to better understand the type and effectiveness of alternatives to ZnO on pig health and welfare.