Meta-analyses of genome wide association studies in lines of laying hens divergently selected for feather pecking using imputed sequence level genotypes

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 ...........

Feather Pecking of Laying Hens in Different Stocking Density and Type of Cage

Both stocking rate and housing systems are main factors influencing the occurrence of feather pecking in laying hens raised in conventional cage system. This study examines the effects of different type of cage and stock density on feather pecking behaviour in hens. Total of 216 Hisex Brown hens at 16 weeks of age were randomly selected and put into 2 types of battery cages: conventional cages ...

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...

Evaluation of potential power gain with imputed genotypes in genome-wide association studies.

BACKGROUND With the beginning of the era of genome-wide association studies methods to obtain 'in silico' genotypes have gained importance. In this context, an evaluation of genome-wide power levels of current marker panels and the power gain achievable with imputed genotypes are of high interest. METHODS Power for single-marker analysis of imputed genotypes is evaluated via a simulation stud...