Influence of light intensity on behavior and performance of broiler chickens.

The influence of two light intensity treatments, 180 and 6 lx, on behavior and performance of broiler chickens was examined in two experiments. The first experiment tested male chickens reared to 9 wk of age and the second experiment tested both sexes reared separately to 6 wk. Behavioral data were collected by scan sampling of behavior recorded on video tape. Standing, walking, and total activity were higher under the 180 lx than the 6-lx treatment (P less than .01), whereas feeding and drinking were not significantly affected by light intensity. Body weight, feed and water consumption, and feed conversion were unaffected by light intensity. Incidence of leg disorders at 6 wk and the percentage of bruised carcasses at 64 days were significantly lower under the higher light intensity treatment in the first experiment, as was mortality to 3 and 6 wk in the second experiment. No significant light intensity X sex interactions were detected. Results did not support the hypothesis that brighter lighting reduces performance due to increased chicken activity. Use of brighter lighting had no adverse effects on performance and there was some evidence that it may have a beneficial effect on welfare by reducing bruising.