2.2. Housing, Feeding, and Management

We raised 40 Ross 708 female broiler chicks in two 116 × 116 cm floor pens with 20 chicks/pen until they reached 2 weeks of age. For the first 2 weeks of life, the chicks were placed on a mixture of Pestell™ pine and spruce and Grreat Choice^® aspen wood shavings that were allowed to build up with excreta. Each pen was provided with a heat lamp, heat mat, and brooder (darkened) area. Chicks were provided with ad libitum feed and water, and with natural light through windows. The temperature was monitored and maintained according to the Ross 708 management guidelines [39], and the chicks were provided with commercial feed throughout the experiment.

When the chicks were 16 days old, we divided the birds of each of the two floors pens across a final six floor pens into groups of six to seven birds per pen. Birds that were kept within one pen during the first 2 weeks of life were kept together (i.e., no mixing of birds between the two original floor pens). These 116 × 116 cm floor pens contained heat mats and heat lamps until the chicks reached approximately 4 weeks old. We differentiated individual birds in each pen using colored backpacks made of colored tape, hair elastics, and soft foam (Figure 1). We checked the backpacks’ fit every three days. Within a week of the experiment’s conclusion, all 39 birds were adopted by sanctuaries and homes.

Image of broiler chick floor pens with heat lamps on. Each pen contained an H (bottom) and T (top) compartment separated by a wooden barrier with two unidirectional polycarbonate push doors. H and T alternated sides daily. The unidirectional push doors are lowered in this image. Weights could be added to the doors, which was only done for the door leading to the T compartment. Water and feed were available in both compartments except during the feed treatment.