Breeding for disease resilience: opportunities to manage polymicrobial challenge and improve commercial performance in the pig industry

Abstract

Disease resilience, defined as an animal’s ability to maintain productive performance in the face of infection, provides opportunities to manage the polymicrobial challenge common in pig production. Disease resilience can deliver a number of benefits, including more sustainable production as well as improved animal health and the potential for reduced antimicrobial use. However, little progress has been made to date in the application of disease resilience in breeding programs due to a number of factors, including (1) confusion around definitions of disease resilience and its component traits disease resistance and tolerance, and (2) the difficulty in characterizing such a complex trait consisting of multiple biological functions and dynamic elements of rates of response and recovery from infection. Accordingly, this review refines the definitions of disease resistance, tolerance, and resilience based on previous studies to help improve the understanding and application of these breeding goals and traits under different scenarios. We also describe and summarize results from a “natural disease challenge model” designed to provide inputs for selection of disease resilience. The next steps for managing polymicrobial challenges faced by the pig industry will include the development of large-scale multi-omics data, new phenotyping technologies, and mathematical and statistical methods adapted to these data. Genome editing to produce pigs resistant to major diseases may complement selection for disease resilience along with continued efforts in the more traditional areas of biosecurity, vaccination and treatment. Altogether genomic approaches provide exciting opportunities for the pig industry to overcome the challenges provided by hard-to-manage diseases as well as new environmental challenges associated with climate change.

Competence to thrive: resilience as an indicator of positive health and positive welfare in animals

“…In this view, environmental variation does not necessarily constitute an environmental challenge, perturbation or disturbance; rather it is environmental variation that cannot be predicted or controlled that poses a challenge to the animal (Jensen and Toates 1997;Lee et al 2018;Kristiansen and Fernö 2020). A capacity for animals to be minimally affected by environmental disturbances or to rapidly recover from them is recognised as resilience (Hine et al 2015;Tedeschi et al 2015;Colditz and Hine 2016;Friggens et al 2017;van Dixhoorn et al 2018;Berghof et al 2019b;Bai and Plastow 2022).…”

“…A type of resilience appears to have been first recognised in farm animals as a distinction between resistance to infestation and resistance to the effects of infestation of sheep with the nematode parasite, Haemonchus contortus (Clunies Ross 1932). Resilience has been assessed in the context of nematode parasite infection (Albers et al 1987;Bisset and Morris 1996;Kelly et al 2013), microbial infection (Mulder and Rashidi 2017;Putz et al 2019;van der Zande et al 2020;Bai and Plastow 2022), high or low temperature exposure (Mengistu et al 2017;Sánchez-Molano et al 2020;Tsartsianidou et al 2021), diet (Steel 2003), feed shortage (María et al 2004), weaning (Hine et al 2019;Revilla et al 2019), routine management within the production environment (Meyer and Colditz 2015;Elgersma et al 2018;Nunes Marsiglio Sarout et al 2018;Nguyen-Ba et al 2020;Poppe et al 2020Poppe et al , 2021bSun et al 2021;Bai and Plastow 2022), and the transition period in the dairy cow (van Dixhoorn et al 2018), among other contexts (e.g. Bushby et al 2018;Brito et al 2020).…”

“…Historically, infectious diseases have attracted the strongest attention in studies of resilience in livestock. Resilience to infection is usually described as the relative level of production at a given level of infection and can be identified by comparison among animals or within an animal over time (Bishop 2012;Knap and Doeschl-Wilson 2020;Bai and Plastow 2022). It is distinguished from resistance, which is described as the relative level of infection an animal develops at a given level of pathogen exposure.…”

“…Neethirajan et al 2017;Brito et al 2020;Sun et al 2021). Assessments at the level of the individual animal of dynamic properties of the trajectory of performance traits such as milk yield, periodicity of physiological and behavioural variables, and complexity of biological functions such as behavioural repertoires are being interpreted as (1) evidence of resilience to environmental perturbations, (2) an indicator of welfare, and (3) an avenue for improving health and welfare through genetic selection (Scheibe et al 1999;Colditz and Hine 2016;Nunes Marsiglio Sarout et al 2018;van Dixhoorn et al 2018;Berghof et al 2019b;Iung et al 2019;Wagner et al 2021;Bai and Plastow 2022). One aim of this review was to examine the merits of these inferences.…”

“…Animal-based measures play a prominent role in welfare assessments and new methods for measuring biological function, natural living and affective state are being developed to complement theoretical and evidencedbased advances in understanding what animals are, what they can be, and how they function (Mellor 2016;Buller et al 2020;Duncan 2020). Advances in the concept of animal resilience and new methods for its measurement are a part of this dynamic (Hine et al 2015;Colditz and Hine 2016;Friggens et al 2017;van Dixhoorn et al 2018;Berghof et al 2019b;Brito et al 2020;Ben Abdelkrim et al 2021;Wagner et al 2021;Bai and Plastow 2022).…”