Divergent selection on feather pecking behaviour in laying hens (Gallus gallus domesticus)

Summary in the original language of the document

A selection experiment was initiated in 1996 in which selection for (HP line) and against (LP line) feather pecking was performed. The foundation stock was a White Leghorn layer strain established in 1970 and maintained since then as a random bred control line at the Institute. Six hatches were produced over three generations. At the age of 68 wk (gen. 0, 1996), 35 wk (gen. 1, 1997), 30 wk (gen. 2, 1998), and 27 wk (gen. 3, 1999) female birds were transferred to observation pens and their feather pecking behaviour was recorded. In each generation, 30 females and 8 males were selected from approx. 200 females and 60 males. Selection criteria was breeding value estimated by animal model on the trait ‘number of bouts of feather pecking per bird per hour’.
Feather pecking behaviour in adult hens was significantly higher in HP than in LP. In generation 2 the following was recorded: Bouts per bird per hour (3.10 versus 1.37, P<0.01), pecks per bird per hour (7.04 versus 3.58, P<0.05) and proportion of hens recorded feather pecking in the 180 minutes observation period (67 versus 56%, P<0.05). In generation 3 the following was recorded: Bouts per bird per hour (4.56 versus 0.63, P<0.001), pecks per bird per hour (13.9 versus 2.51, P<0.001) and proportion of hens recorded feather pecking in the 180 minutes observation period (75 versus 49%, P<0.001).
In generation 3, plumage condition was better in LP on neck, breast, back, wings and tail, as well as overall (P<0.001). Body weight did not differ between lines in generation 2, but in generation 3, HP hens were on average heavier than LP hens at the age of 27 weeks (1435 g versus 1371 g, P<0.001).