Effects of clipping of flight feathers on resource use in Gallus gallus domesticus

Abstract

Ground-dwelling species of birds, such as domestic chickens (Gallus gallus domesticus), experience difficulties sustaining flight due to high wing loading. This limited flight ability may be exacerbated by loss of flight feathers that is prevalent among egg-laying chickens. Despite this, chickens housed in aviary style systems need to use flight to access essential resources stacked in vertical tiers. To understand the impact of flight feather loss on chickens' ability to access elevated resources, we clipped primary and secondary flight feathers for two hen strains (brown-feathered and white-feathered, n = 120), and recorded the time hens spent at elevated resources (feeders, nest-boxes). Results showed that flight feather clipping significantly reduced the percentage of time that hens spent at elevated resources compared to ground resources. When clipping both primary and secondary flight feathers, all hens exhibited greater than or equal to 38% reduction in time spent at elevated resources. When clipping only primary flight feathers, brown-feathered hens saw a greater than 50% reduction in time spent at elevated nest-boxes. Additionally, brown-feathered hens scarcely used the elevated feeder regardless of treatment. Clipping of flight feathers altered the amount of time hens spent at elevated resources, highlighting that distribution and accessibility of resources is an important consideration in commercial housing.

Keywords: bird; feather loss; flapping flight; locomotion; wing damage; wing wear.

Figure 1.

Diagram of experimental pen set-up including two views: frontal and bird's eye view. Each hen was housed in a floor pen (183 L × 244 W × 290 H cm) furnished with two elevated platforms (122 L × 31 W × 70 H cm), a high perch (244 L at 150 H cm), a low perch (122 L at 70 H cm), two 5 kg hanging feeders fixed with two wooden boards and an RFID antenna, and two individual nest-boxes each containing an RFID antenna.

Figure 2.

Diagram of treatments applied to flight feathers of laying hens (n = 120) at the end of week 0, following baseline measurement acquisition. Treatment groups included the control group in which all flight feathers were left intact (4 hens/pen), the half clip group in which the primary flight feathers were trimmed (3 hens/pen) and the full clip group in which all of the primary and secondary flight feathers were trimmed (3 hens/pen).

Figure 3.

Experimental timeline. The experiment took place over the course of eight weeks. RFID equipment was rotated among 12 pens that were grouped into one of four groups (three pens per group). Two groups were recorded each week, resulting in an alternating recording schedule. On week 0, a baseline RFID recording was taken, followed by the application of treatments (represented as scissors in the diagram). Recordings were then taken every two weeks post-treatment application for six weeks.

Figure 4.

Individual feeder assembly. A duct-taped wrapped cardboard ring was placed into the base of a 5 kg hanging feeder. Two wooden boards were aligned with the opening in the ring and were secured onto the body of the feeder with four screws. An RFID antenna was attached to the base of the feeder with plastic zip ties, and the cardboard wrapped lid was placed atop the opening at the top of the feeder.