Comparison of resistance of various poultry lines to infection by Salmonella enteritidis

A study was undertaken to determine the susceptibility or resistance of 9 outbred experimental or commercial poultry lines to Salmonella enteritidis PT4. Young chicks were inoculated either intramuscularly or orally just after hatching. After intramuscular challenge the lines could be divided into susceptible lines (LD 50% < or = 10(2) Salmonella per animal), intermediate lines (LD 50% about 10(4) Salmonella) and resistant lines (LD 50% > 10(5) Salmonella). The results obtained after oral challenge confirmed these 3 groups for both mortality rates and the probability of the presence of salmonellae in the spleen and liver. There was no difference between lines concerning caecal carriage.