Biotemas (Jun 2010)
Effects of different lighting programs on semi-heavy laying hens reared in open shelters
Abstract
The effects of of lighting programs on the zootechnic performance and egg quality of semi-heavy laying hens were evaluated. Three light programs were tested: continuous lighting of 15h (artificial+natural), intermittent lighting (two photophases of 15s between the natural light) and natural increased lighting. 192 birds were used, accommodated in a shed divided into three environments in such a way that the lighting of any given one did not interfere with the others. The experimental period lasted 112 days, during which the zootechnic performance was evaluated through the egg production, feed intake, weight and mass of eggs. The quality of the eggs was valued through their specific gravity, weight and shell thickness, and Haugh unit measurement. The design was entirely randomized, with eight repetitions, and the averages of the treatments were compared by the SNK test (5%). In the results of performance, the feed intake and egg weight were similar (P0.05) under the natural light program. The quality of the eggs was not altered (P<0.05) by any of the programs. It was concluded that the intermittent lighting program could be use in open sheds, maintaining the zootechnic performance of semi-heavy laying hens and without altering the quality of their eggs. In contrast, the program of natural increased light reduces egg production.
