Genetic and environmental effects on the response of chickens to avian adenovirus group II infection.

The effects of husbandry procedures on an intravenous challenge with avian adenovirus group II were studied in lines of White Leghorns selected for high (HH) and low (LL) antibody response to sheep erythrocytes and their reciprocal crosses (HL and LH). Husbandry procedures were deprivation or no deprivation of water during the first week after hatching (ES), habituation or no habituation to humans throughout life, and flock stability or instability (LS) 24 hours prior to an intravenous challenge with avian adenovirus group II. Spleens of chickens were weighed 6 days after challenge. HL chicks were most susceptible and LH chicks were most resistant to avian adenovirus group II. Chicks subjected only to ES or no stress responded similarly and were less affected than those subjected to LS or to both ES and LS. There were major genetic-environment interactions which affected spleen size.