Preferences of Growing Fowls for Different Light Intensities in Relation to Age, Strain And Behaviour
The preferences of broiler and layer strains of fowl for four different intensities of incandescent luminaire (6, 20, 60 and 200 lux; Osram, 60W, pearl) were tested at 2 and 6 weeks of age. With each strain, four replicates of 12 birds were each allowed to move freely between four compartments illuminated continuously at the […]
The locomotion of dairy cows in passageways with different light intensities
Guidelines for the housing of dairy cows do not address the provision of supplementary lighting in passageways, other than for inspection of the animals. Two experiments were conducted to investigate whether lighting passageways to various intensities influenced the locomotion of dairy cows. The first experiment compared the locomotion of dairy cows in a dark or […]
Absence of daily rhythms of prolactin and corticosterone in Adelie penguins under continuous daylight
Plasma prolactin and corticosterone levels were measured in free-living Ad6lie Penguins (Pygoscelis adeliae) at TorgersenI sland, Antarctica (64?S latitude), at 4-hr intervals throughout the day during early January 1997 and examined for evidence of a 24-hr rhythm. At this season and latitude, natural daylight is continuous. No significant change in the plasma level of either […]
The impact of chronic environmental stressors on growing pigs, Sus scrofa (Part 2): social behaviour
The effects of common and concurrent environmental stressors on the social behaviour of farm animals are poorly understood. Here, we report the results of a multifactorial experiment designed specifically to examine the individual, additive or interactive effects of elevated ammonia, noise and low light (LL) levels on the social behaviour of growing pigs. Social behaviour […]
Light colour and intensity alters reproductive/seasonal responses in Japanese quail
An extensive literature is available on the photoperiodic responses of avian species but studies on light colour and wavelength from light emitting diode (LED) sources on reproduction are limited. Hence, an experiment was designed to study the effect of different colours and intensities of light on the reproductive responses of Japanese quail. Three-week old quail […]
Dose-dependent responses of avian daily rhythms to artificial light at night
Recent studies have shown that animals are affected by night-time light exposure. Light is a continuous variable, but our knowledge on how individuals react to different light intensities during the night is limited. We therefore determined the relationship between night light intensity and the behaviour and physiology of great tits (Parus major). We measured daily […]