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

A selection experiment was initiated in 1996 in which selection for (HP lin e) and against (LP line) feather pecking was performed. The foundation stoc k 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 prod uced over three generations. At the age of 68 weeks (generation 0, 1996), 3 5 weeks (generation 1, 1997), 30 weeks (generation 2, 1998), and 27 weeks ( generation 3, 1999) female birds were transferred to observation pens and t heir feather pecking behaviour was recorded. In each generation, 30 females and 8 males were selected from approximately 200 females and 60 males. The selection criterion was breeding value estimated by animal model on the tr ait '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: 3.10 versus 1.37 bouts per bird per hour (P < 0.01), 7.04 versus 3.58 pecks per bird per hour (P < 0.05) and the proportion of hens recorded feather pecking in the 180 min o bservation period was 67 versus 56% (P < 0.05). In generation 3 the followi ng was recorded: 4.56 versus 0.63 bouts per bird per hour (P < 0.001), 13.9 versus 2.51 pecks per bird per hour (P < 0.001) and the proportion of hens recorded feather pecking in the 180 min observation period was 75 versus 4 9% (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 < 0.0 01). (C) 2001 Elsevier Science B.V. All rights reserved.