THERMAL-STRESS ON CHICKENS IN TRANSIT

1. An artificial chicken, 'Gloria', was constructed to simulate heat e xchanges of poultry during transport. Tests of the instrument in a win d tunnel showed it to have insulation properties similar to that of a live bird. 2. Gloria accompanied chickens in two types of transport mo dules, A (enclosed) and B (open). The average temperature difference b etween inside and outside the loaded vehicles when stationary and in m otion were 14.0 and 7.6 for Type A and 8.8 and 6.0 for Type B. Average air movement while vehicles were in motion was 0.5 m/s for Type A and 3.3 m/s for Type B. 3. Measurements of sensible heat loss from Gloria at different temperatures and wind speeds were compared with publishe d estimates of thermoneutral heat production and thermal insulation fo r well and poorly feathered chickens to estimate the range of thermal stresses likely to be experienced by chickens in transit. 4. The resul ts showed that the combination of circumstances necessary to ensure th ermal comfort for birds both at rest and in motion is very rare (e.g. only between 7 and 8-degrees-C for well feathered birds in enclosed ve hicles). It is, however, possible to ensure thermal comfort over a wid e range of ambient air temperatures by appropriate control of air move ment within the vehicle whether at rest or in motion.