Differentially expressed genes for aggressive pecking behaviour in laying hens

Severe feather-pecking in free-range ISA Brown laying hens

................................................................................................................................ 37 CHAPTER 1: General Introduction ......................................................................................... 44 TYPES OF BIRD-TO-BIRD PECKING .................................................................................. 47 HOUSING SYSTEMS ...........

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

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 weeks (generation 0, 1996), 35 weeks (generation 1,...

Controlling Feather Pecking & Cannibalism in Laying Hens without Beak Trimming

Relationship between feather pecking and ground pecking in laying hens and the effect of group size.

The aim of this experiment was to study the relationship between feather pecking and ground pecking in laying hens and the effect of group size on feather pecking behaviour. Hisex White hens were kept in floor pens in group sizes of 15, 30, 60 and 120 birds, each with four replicates. Behavioural observations were performed at four different ages and focused on the number of feather pecks and a...

Variance components and selection response for feather-pecking behavior in laying hens.

Variance components and selection response for feather pecking behavior were studied by analyzing the data from a divergent selection experiment. An investigation indicated that a Box-Cox transformation with power lambda = -0.2 made the data approximately normally distributed and gave the best fit for the model. Variance components and selection response were estimated using Bayesian analysis w...