AvaliaÃÃo de programa de iluminaÃÃo para poedeiras leves e semi-pesadas / Evaluation of lighting program for light and semiheavy layers

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

To evaluate the effect of lighting programs for light and semi-heavy layers, two experiments at the Department of Animal Science of the Federal University of Lavras were conducted. An intermittent lighting program and another with only natural lighting on days of growing lighting as compared with a continuous program by utilizing 288 light and 192 semi-heavy layers were tested. The hens were housed in a house divided into three environments in such a way the lighting of one did not interfere with that of the other. The experimental period lasted 112 days, divided into four periods of 28 days. The design utilized was the completely randomized with restriction in the treatments and eight replicates. The means of the treatments were compared with the SNK test (5%). In the experiment with light layers, the hens of the continuous lighting program presented greater consumption of ration (P<0.05) and worse feed conversion whereas those of the natural light program, greater yield and egg mass and smaller Haugh unit. The hens in the program with intermittent lighting presented better viability (P<0.05) and less albumen height and weight of eggshell. In the experiment with semi-heavy layers, the hens of the natural light program presented less yield and egg mass in addition to poorer feed conversion. It follows that intermittent lighting program and only natural lighting on days of growing lighting for light layers in the late production may be used in open houses keeping yield without altering egg quality. Semi-heavy layers submitted to natural light present reduction in the performance, nevertheless, egg quality is kept. For these birds, intermittent lighting program enables to keep yield without altering egg quality.

ASSUNTO(S)

natural light luz natural intermittent light lighting programs programa de iluminaÃÃo zootecnia iluminaÃÃo contÃnua iluminaÃÃo intermitente continuous light dia subjetivo

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