Genetic improvement on feather pecking behaviour by selection is promising

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Archived at http//orgprints.org/00001564
Genetic improvement on feather pecking behaviour
by selection is promising Guosheng Su, Jørgen B.
Kjaer and Poul Sørensen Danish Institute of
Agricultural Sciences, P.O. Box 39, Foulum, DK -
8830 Tjele, Denmark

• Objectives
• To investigate genetic variation in feather
  pecking behaviour and genetic improvement on this
  trait by selection, using an appropriate
  data-transformation and an animal model.
• Materials and Methods
• Selection experiment
• Line LP was selected for low feather pecking,
  line HP for high feather pecking, conducted for
  four generations.
• Selection was based on number of feather pecking
  bouts.
• Feather pecking for females was recorded at
  about 30 weeks in floor pens for 3 hours.
• A bout a series of continuous peaking direct
  to the same body part in the same chicken.
• Statistical analysis
• The data for each line were analysed separately
  using an animal model
• yt year-hatch pen full-sib additive
  genetic residual
• where yt is the number of bouts of feather
  pecking in Box-Cox transformation scale, i.e.,
• yt (y? - 1)/?, for ? ? 0 yt log(y), for ?
  0 ( ygt0)

No effects of observing pen and full-sib group
can be found, but a heritability of 0.18 and 0.15
for number of bouts in line LP and HP,
respectively (Table 2).
Genetic changes by selection was significant
(Figure 2). After 4 generations of selection the
total response was 62 of base population mean in
line LP and 84 in line HP.

• Conclusions
• Large phenotypic variation for feather pecking
  behaviour.
• No full-sib group effect can be found, indicating
  that maternal effect is negligible.
• Moderate or low heritability.
• Genetic improvement on feather pecking by
  selection is effective.

Bout number averaged over selection generations
in line HP was much higher than that in line LP
(Table 1). The coefficient of variation was about
100 in transformed scale and 300 in observed
scale.