Laying hens reactions on artificial light in a floor housing system
G. Gustafsson, E. von Wachenfelt
(Swedish University of Agricultural Sciences, Department of Rural Buildings, S- 230 53 Alnarp, Sweden)
Abstract: Investigations about laying hens reactions on different artificial light conditions were carried out in a climate chamber equipped with a floor housing system for laying hens. The activity of the hens was considerably higher during light periods compared to dark periods. The light intensity had no influence on the total activity of the hens. The release of moisture increased during light periods probably due to increased activity increasing respiration rate but also on increased scratching in the bedding material. The daily average was 6.29 g hen-1 h-1 at 4 lux and 5.97 g hen-1 h-1 at 93 lux which corresponded to a difference of 5%. The level of light intensity seemed to have little influence on the release of moisture. The total release of heat was slightly higher during light periods compared to dark periods. Explanations can be increased activity but also feed intake increasing the metabolic rate during light periods. The daily average of total heat production was 17.0 W per hen at 4 lux and 14.7 at 93 lux which corresponds to a difference of 16%. The release of carbon dioxide increased during light periods probably due to increased activity and respiration. The preference of light intensity was studied by varying the intensity between two parts of the housing system. The hens’ preferences were measured by registration of the number of eggs and amount of manure laid in the two parts of the system. It was a small tendency to prefer a lower intensity for laying eggs but a higher intensity were manure was placed. The preference to lay eggs was also studied when one part of the chamber just had one concentrated light source. The other part was nearly dark. Even in this case the hens preferred to lay eggs in the dark part. More manure was laid in the light part. The preference of colour was studied by using coloured light in one part of the chamber and by using white light in the other part. Changes in amount of eggs and manure were measured and compared to the conditions with equal concentrations of white light. The hens preferred white light before green light for the laying of manure but had equal preference for laying eggs. There were preferences for blue light both for laying eggs and laying manure. It was a small preference for red light for laying eggs but equal preference for laying manure.
Keywords: Laying hens, artificial light, heat, moisture, carbon dioxide, Sweden
Citation: Gustafsson G and E. von Wachenfelt. Laying hens reactions on artificial light in a floor housing system. Agric Eng Int: CIGR Journal, 2010, 12(2): 21-28.