Vertical temperature profiles at bird level in broiler houses.

1. The temperature in the close vicinity of commercial broilers was studied in relation to the setpoint temperature throughout the rearing period. 2.

Artificial light sources and their influence on physical activity and energy expenditure of laying hens.

1. The influence of fluorescent and incandescent artificial lighting in a 16L:8D day/night schedule on number and intensity of movements, and on total, resting and activity-related energy expenditure was investigated. 2.

Responses of broiler chickens to high-frequency and low-frequency fluorescent light.

1. The influence of the flicker frequency on physical activity and energy expenditure of broilers was studied using commercially available high-frequency (HF) and low-frequency (LF) fluorescent lamps in a 23L:1D lighting schedule. 2.

Physical activity and energy expenditure of laying hens as affected by light intensity.

The influence of light intensity using incandescent bulbs in a 16L:8D day:night schedule on the number and strength of movements and on total, resting and activity-related energy expenditure was investigated. Movements were classified into 10 activity levels of progressively increasing vigour. The number of movements at all activity levels was significantly positively correlated with the logarithm of the light intensity.

Automatic gravimetric calorimeter with simultaneous recording of physical activity for poultry.

An automatic calorimeter, based on gravimetric principles, for studies on the energy metabolism of the fowl, with simultaneous recording of the physical activity, is described. In order to reduce errors in the determination of heat production to below 3% a three hour experimental period is necessary. The length of this period in comparison to that of the Pettenkofer system is discussed.