Abstract
Effect of low environmental temperature on the blood sugar, body temperature, respiratory rates and egg prduction was investigated in laying hens. Seventyfive white Leghorn hens, kept in single cage, were exposed to the following cold environmental temperature for ten days: outdoor temperature in January (-7.6-14.5°C) (exp. 1), 5°C (exp. 2) and 5°C with air blast of 1meter/sec velocity (exp. 3). Before and after exposure to the low temperature, they were kept at 20°C for 20 and 10 yays, respectively.
Blood sugar level decreased significantly soon after moving hens to those cold environments, particularly 5°C with air blast. Body temperature declined at the inital stage of 5°C environment with or without air blast, but did not show any appreciable change under the outdoor temprature. Respiratory rates were almonst constant throughout the experiments. Fall of egg production, decrease of egg weight and increase of shell thickness were observed after moving to those cold environments.
These results show that exposure to the cold environment, particularly with air blast has a significant influence on the pysiological characteristics of layings.
