BACK TO QUEBEC CITY 2002 TITLES
Effect of light type and
level of illumination on nest site selection in broiler breeder fowl: Do
hens prefer dark nests?
K.C. Sheppard, I.J.H. Duncan
and T.M. Widowski
University of Guelph,
Guelph, Canada
Broiler breeder hens lay more floor eggs than commercial egg layers. This is an economic concern, since floor eggs are not considered suitable for incubation, and may indicate that some hens regard the nest boxes as inadequate. Darkness has been suggested to be an attractive property in a nest site.
We tested the effects of light type and level of illumination on nest box usage by broiler breeders. Ross 308 hens (N=468) were randomly assigned to one of three light treatments, high pressure sodium (HPS), compact fluorescent (CF) and incandescent (IN). Light intensity measurements averaged 108, 52 and 43 lux (122, 68 and 65 gallilumens) for HPS, CF and IN respectively. A unit of 10 nest boxes, in two tiers of five, was hung on either the right or left wall of each pen. Direct illumination into the right or left half of each unit was blocked by hanging an opaque shade between the light source and nest box. Locations of the first 6 hens to select a nest site in each pen were recorded for 20 days. Each group of hens was then moved to a new pen in which nest box and shade location was opposite of that in the original pen (period 2). Data were recorded as before. Individual variation in nesting behaviour was tested by recording the nest site choice (shaded or lit) of 2-3 individuals per pen that were originally observed to choose a lit nest box. At least 5 locations were recorded per hen, during period 2 only.
Considering hens nesting in lit or shaded boxes only, 52%, 50%, and 54% chose shaded boxes in HPS, CF, and IN respectively. This suggests that different properties of light and the presence of shade in the nest box do not affect nest site choice by broiler breeders overall. Considering individual hens that chose a lit box at least 3 out of 5 times, 70%, 75% and 22% chose consistently in HPS, CF and IN respectively. This suggests that there may be a strong preference for darkness or light among individual hens.