Effect of light schedule and dimming in early life on bone development in the broiler chicken

Carla van der Pol*†, Christiaan Buitink†, Conny Maatjens*†, Inge van Roovert-Reijrink*, Henry van den Brand†, Roos Molenaar*

*HatchTech B.V., P.O. Box 256, 3900 AG Veenendaal, the Netherlands. †Adaptation Physiology Group, Wageningen University, P.O. Box 338, 6700 AH Wageningen, the Netherlands.

Leg problems may partly be prevented by providing a broiler chicken with optimal light schedules for bone development in early life. It can be speculated that continuous light and a sudden switch from light to darkness and vice versa lead to more stress and, therefore, decrease bone development than a prolonged dark period and dimming (a gradual transition, as in nature) in early life.

Newly hatched Ross 308 chickens from a 27 week old broiler breeder flock (n = 500) were exposed to an initial continuous light period of 12 hours. Thereafter, 5 light schedules were applied until 4 days post-hatch: 1. Continuous light (24L); 2. Short dark period without dimming (2L:1D abrupt); 3. Short dark period with dimming (2L:1D dimming); 4. Long dark period without dimming (2L:6D abrupt); 5. Long dark period with dimming (2L:6D dimming). Body weight and feed intake were determined on day 0 and day 4 post-hatch. At day 4 post-hatch, 35 chickens per treatment were sacrificed to determine femur and tibia characteristics. Data were analyzed using the GLM procedure with individual body weight as a covariable for the bone characteristics. Download the entire article via the button below.