Coronary arterial lesions in chickens: origin and rates of development in relation to sex and social factors.

• The records of the Philadelphia Zoological Garden suggest that social (intraspecific) interaction may be a major factor in the origin and progress of stenosing lesions of the coronary arteries that lead to myocardial infarction in many species of mammals and birds." The present study was designed to explore this possibility. The origin and progress of coronary arterial lesions in cocks and hens have been traced from age 7 to 51 weeks, and rates of progress of the lesions measured quantitatively and related to age, sex, and social situation.