116. Laying hens tweet: they also lead and follow – implications for genetic selection against gregarious nesting

Abstract

Gregarious nesting occurs when a hen chooses a nest already occupied while other nests are vacant, increasing welfare and production problems. This study aims to propose two predictors of gregarious nesting: weighted indegree (WID) and weighted outdegree (WOD), which are the number of times a hen entered an individual nest next to a vacant nest or an occupied nest, respectively. Nesting behaviour was recorded using individual electronic nests for 210 days. Genetic parameters for WID, WOD and nesting behaviour traits were estimated for 1,268 and 1,080 Rhode Island Red and White Leghorn respectively. For both lines, heritability estimates were high for WID (0.40/0.53) and low for WOD (0.12/0.15). Moderate genetic correlations were estimated between WID and WOD (+0.26/-0.35) and strong genetic correlations with some nesting behaviour traits. WID and WOD could help to select against gregarious nesting but the effects for hens using collective nests remain to be evaluated.