Thermal stress on chickens in transit.

1. An artificial chicken, 'Gloria', was constructed to simulate heat exchanges of poultry during transport. Tests of the instrument in a wind tunnel showed it to have insulation properties similar to that of a live bird. 2. Gloria accompanied chickens in two types of transport modules, A (enclosed) and B (open). The average temperature difference between inside and outside the loaded vehicles when stationary and in motion 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 published estimates of thermoneutral heat production and thermal insulation for well and poorly feathered chickens to estimate the range of thermal stresses likely to be experienced by chickens in transit. 4. The results showed that the combination of circumstances necessary to ensure thermal 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 vehicles). It is, however, possible to ensure thermal comfort over a wide range of ambient air temperatures by appropriate control of air movement within the vehicle whether at rest or in motion.

Noise output of hens subjected to interrupted lighting regimens.

1. Noise output from domestic hens subjected to an interrupted lighting regimen began before dawn of the apparent day. 2. Noise output did not cease during the scotoperiod(s) which interrupted the apparent day. 3. Differential noise outputs during the 30 min. 4 h and 10 h scotoperiods of a 1L:7(30D:30L):4D:2L:10D regimen indicated that the hen's interpretation of darkness, even within the apparent day, was complex and probably dependent on several factors. 4. Noise output data suggested that the intense feeding behaviour at the end of the apparent day, effected by the interrupted lighting regimen, appeared to prevent the pre-dusk reduction in activity observed in conventionally lighted birds. 5. Noise output was negligible during the scotoperiod which the hen interpreted as night.