JSHAP Online Ahead of Print: A Norwegian observational study of feed conversion efficiency in Duroc and Landrace grower pigs seropositive for influenza A (H1N1) pdm09 virus
Abstract:
Objective: Investigate the influence of influenza A(H1N1)pdm09 virus (pH1N1v) on feed conversion efficiency (FCE) in Norwegian Landrace and Duroc pigs.
Materials and methods: This observational study analyzed the growth and serological data of 1954 grower pigs collected from 43 nucleus breeding herds in eastern Norway between 2009 and 2012. Serial serological tests, enzyme-linked immunosorbent assay, and hemagglutination inhibition were used to detect pH1N1v antibodies in pigs weighing 100 kg. Statistical analyses included mixed-effects regression modelling, Cox regression, and Kaplan-Meier Failure analysis to assess the effects of breed on pH1N1v influence on growth performance.
Results: Duroc pigs experienced a greater reduction in FCE (5.6%; 95% CI, 5.5%-5.7%) compared to Landrace pigs (3.5%; 95% CI, 1.3%-5.6%) when exposed to pH1N1v. Seropositive pigs of both breeds maintained normal growth rates under ad libitum feeding conditions. To reach 100 kg body weight, seropositive Landrace pigs consumed 2.4 kg (95% CI, 0.9-3.9 kg) more feed, while Duroc pigs consumed 3.8 kg (95% CI, 3.7-4.0 kg) more feed than their seronegative counterparts.
Implications: Results suggest breed-specific differences in resilience to influenza even though the overall appetite of seropositive pigs was unimpaired during the growth phase (approximately 33-100 kg body weight). Study findings highlight the economic implications of
selecting appropriate breeds for specific environmental challenges. However, the study’s observational nature limits the ability to infer causality and may not be generalized to other breeds or crossbreeds. By understanding breed-specific responses to influenza, producers can optimize breed selection strategies to enhance overall herd resilience and efficiency, contributing to more sustainable pork production.
Er J. A Norwegian observational study of feed conversion efficiency in Duroc and Landrace grower pigs seropositive for influenza A (H1N1) pdm09 virus. J Swine Health Prod. Published online December 9, 2024. https://doi.org/10.54846/jshap/1395