Surface and Cloacal Temperatures in Chicks of Different Genetic Stocks Given an Escherichia coli Inoculation

The effect of Escherichia coli on surface and cloacal temperatures was assessed in pure line and hybrid chicks from both white rock and leghorn stocks. Body weights, surface temperatures, and cloacal temperatures were obtained from 2 to 30 days of age. Two groups of chicks, one 8 days and the other 30 days of age, were inoculated via the caudal thoracic air sac with E. coli, and effects were quantified as changes in body weight, surface and cloacal temperatures, lesions on heart and air sacs, and mortality. Pure line white rock chicks had the highest mortality from the E. coli inoculation and proportionally lost the most weight over the 48-hr period immediately following inoculation. Chicks inoculated at 30 days of age were affected more severely than those inoculated at 8 days. Surface and cloacal temperatures were not reliable predictors of resistance to an E. coli inoculation.