Disease incidence and immunological traits for the selection of healthy pigs A review

Abstract

Disease is a major issue in animal production systems and society demands that the use of medicines and vaccines be reduced. This review describes the breeding approaches that could be used to improve disease resistance and focuses especially on their application to pigs. Disease reduction by genetic means has certain advantages through cumulative and permanent effects, and direct and indirect selection methods are available. Direct selection for disease incidence requires, besides a unique pig identification and disease registration system, challenge routines that are inconvenient in intensive pig production. Indirect selection for the expression of immune capacity may be an alternative but requires detailed knowledge of the different components of the immune system. There is ample opportunity for genetic improvement of the immune capacity because immune traits show substantial genetic variation between pigs. We therefore conclude that indirect selection via immune traits is very interesting, also for practical implementation, and that there is an urgent need for knowledge, within lines, about the genetic relationships between immune capacity traits and resistance to specific diseases or to disease incidence in general. Furthermore, knowledge about the relationship between immune system traits and production traits is needed as well as knowledge about the effect of selection on the epidemiology of disease at a farm/population level and on the host-pathogen interaction and coevolution.

Age, gender and litter‐related variation in T‐lymphocyte cytokine production in young pigs

“…Infectious diseases cause major economic and welfare problems in current pig husbandry and pose a threat to human health by risk of zoonoses. Current focus in pig health care aims mainly at prevention of infection through hygienic measures, through vaccination and by supplementation of antibiotic growth promoters in feed 1,2 . However, apart from monocausal infectious diseases modern pig husbandry faces challenges with regard to the combat of multifactorial diseases such as porcine respiratory disease complex, post weaning multi‐organ syndrome and porcine dermatitis nephritis syndrome 3–5 .…”

Selection for lean growth and food intake leads to correlated changes in innate immune traits in Large White pigs

“…The relationship between realized performance under commercial conditions and disease resistance and health traits is likely to be complex (Knapp and Bishop, 2000;Colditz, 2002;Visscher et al, 2002). Additionally, it is not straightforward to directly measure resistance to a single pathogen, let alone resistance to many pathogens.…”

Transcriptomic basis of neutrophil ratio variation induced by poly I:C stimulation in porcine peripheral blood

“…Therefore, genetic improvement of the disease resistance of pigs should be enhanced. Some phenotypic immune traits have been used to identify disease resistance [1] , therefore, analysis of the transcriptome and the phenotypic immune traits to identify individual difference in pigs could be used to investigate the genetic basis of antiviral capacity and disease resistance.…”