Selective breeding for high natural antibody level increases resistance to avian pathogenic Escherichia coli (APEC) in chickens

Body Weight Deviations as Indicator for Resilience in Layer Chickens

“…For objective 3, data of infection experiments of the NAbselection lines were used to investigate the relationship between resilience and disease resistance. An additional G4 and G6 were bred during the NAb-selection experiment, and inoculated with APEC, see Disease Resistance: APEC Mortality and APEC Lesion Scores and Berghof et al (2019a) for more details.…”

“…Two inoculation experiments were performed with additionally bred G4 and G6 chickens, as described by Berghof et al (2019a). Care was taken to select one male and one female of each family (where possible) per treatment to have a balanced representation of both NAb-selection lines.…”

“…Briefly, at 8 days of age, chickens of both selection lines received an intratracheal inoculation of 0.2 ml phosphate buffered saline containing 10 8.20 colony-forming units (CFU)/ milliliter APEC in the additional G4 (197 individuals in total), or 10 6.64 CFU/ml APEC in the additional G6 (180 individuals in total) (adjusted from Berghof et al, 2019a). These treatments were selected, because they had the largest variation in mortality (10 8.20 CFU/ml) and lesion scores (10 6.64 CFU/ml) (Berghof et al, 2019a, see Berghof et al, 2019a for all treatments).…”

“…Surviving High line chickens also had lower total lesion scores (i.e. morbidity) compared to surviving low line chickens at the end of the experiment (Berghof et al, 2019a). It was hypothesized that the NAb-selection lines differ in general (bacterial) disease resistance (Berghof, 2018).…”

Data_Sheet_2.pdf

“…Since the emergence of resistant bacteria might impair the efficacy of antibiotic treatment, alternative approaches to combating bacterial infections in poultry are necessary. One possibility is the development of vaccines (2), another selective breeding aimed at higher intrinsic resistance (3). For a rational approach to either of the strategies, it is however necessary to understand the host response to the infection.…”