National Avian Research Facility
National Avian Research Facility

Light Sussex

Closed outbred line held under SPF conditions.


The Light Sussex is a domestic chicken breed, that is considered a dual-purpose breed, raised both for meat and for eggs. Our Light Sussex chickens are maintained as a closed outbred population in our SPF (specified pathogen free) facility. These birds were relocated from the Pirbright Institute (Compton laboratories) in 2014. They were originally obtained from a commercial breeder in 1961. The NARF’s Light Sussex chickens are known to have MHC haplotypes; B132, 133, 134, 135. In addition, birds are susceptible to LLV subgroups B, and D (not A and E), and to Eimeria spp. Birds are resistant to Marek’s Disease VirusThe MHC haplotypes and differential resistance and susceptibilities of the lines to pathogens have not been validated in recent years.


Light Sussex chickens held under SPF conditions have been used to better understand a range of avian and zoonotic pathogens. Birds held under SPF conditions are particularly useful because they lack maternal antibodies which are often present in naturally exposed commercial flocks, but can interfere with study results. SPF Light Sussex chickens, have been used to evaluate vectored vaccines against Campylobacter1, understand the population dynamics of Campylobacter during colonisation2, and evaluate the role of specific virulence factors3. They have been used as a model of Salmonella colonisation, for example in a comprehensive screen of transposon mutants, that assigned roles to ~3000 Salmonella Typhimurium genes in chickens4. Light Sussex birds have also been used extensively in research on Eimeria infection (also known as Coccidiosis - a parasitic disease of the intestinal tract). For example, they have been used to develop vaccines that use transgenic Eimeria to induce cross-protection against different Eimeria spp5 and to evaluate Eimeria as a vector for heterologous vaccinal antigens6. As Light Sussex chickens are a popular domestic breed, they are also a useful model to study various aspects of behaviour and physiology. 


  1. Buckley, A. M. et al. Evaluation of live-attenuated Salmonella vaccines expressing Campylobacter antigens for control of C. jejuni in poultry. Vaccine 28, 1094–1105 (2010).
  2. Coward, C. et al. Competing isogenic Campylobacter strains exhibit variable population structures in vivo. Appl. Environ. Microbiol. 74, 3857–3867 (2008).
  3. Howard, S. L. et al. Campylobacter jejuni glycosylation island important in cell charge, legionaminic acid biosynthesis, and colonization of chickens. Infect. Immun. 77, 2544–2556 (2009).
  4. Chaudhuri, R. R. et al. Comprehensive assignment of roles for Salmonella typhimurium genes in intestinal colonization of food-producing animals. PLoS Genet. 9, e1003456 (2013).
  5. Pastor-Fernández, I. et al. Development of cross-protective Eimeria-vectored vaccines based on apical membrane antigens. Int. J. Parasitol. 48, 505–518 (2018).
  6. Clark, J. D. et al. Eimeria species parasites as novel vaccine delivery vectors: Anti-Campylobacter jejuni protective immunity induced by Eimeria tenella-delivered CjaA. Vaccine 30, 2683–2688 (2012).