Nest preference and laying duration traits to select against floor eggs in laying hens

Abstract

Background Floor eggs, which are defined as eggs that hens lay off-nest, are a major issue in cage-free layer poultry systems. They create additional work for farmers because they must be collected by hand. They are also usually soiled or broken, which results in economic losses. Nonetheless, knowledge about the genetics of nesting behavior is limited. The aim of this study was to estimate genetic parameters for traits related to nest preference for laying and to time spent in the nests used for laying (laying duration). Methods Two pure lines of laying hens were studied: 927 Rhode Island Red and 980 White Leghorn. Electronic nests were used to record the nesting behavior of these hens in floor pens from 24 to 64 weeks of age. Nest preference was studied based on the mean distance between nests used for laying and the percentage of nests used for laying. Laying duration was studied based on mean laying duration, mean duration in the nest before laying, and mean duration in the nest after laying. Genetic parameters were estimated for each line using a restricted maximum-likelihood method applied to a pedigree-based multi-trait animal model. Results Estimates of genetic parameters were similar for the two lines. Estimates of heritability ranged from 0.18 to 0.37 for nest preference traits and from 0.54 to 0.70 for laying duration traits. Estimates of genetic correlations of these traits with clutch number or mean oviposition time were favorable. Positive genetic correlations were estimated between nest preference and laying rate in the nests or nest acceptance for laying (+ 0.06 to + 0.37). Conclusions These results show that genetics influences traits related to nest preference and laying duration. Selecting hens that have no preference for particular nests and spend little time laying in the nests could help optimize nest use, reduce their occupation rate, and thus decrease the incidence of floor eggs in cage-free systems. Genetic correlations of these traits with other traits of interest related to hen welfare and egg quality have yet to be estimated.

Genetic parameter estimates for the use of an aviary with winter garden by laying hens

“…The average duration spent in the different zones within the aviary ranged from 37.57 to 355.38 min, while the lowest and highest duration spent in a zone was observed for the WG and LIT, respectively. The average duration spent in the NBT was found to be 54.26 min, a value within the range reported by Bécot et al. (2023) for mean laying duration ( MLD ).…”

“…Genetic parameter estimates of behavioral traits in laying hens housed in aviary systems is in a nascent phase ( Bécot et al., 2021 , 2023 ). These behavioral traits encompass nesting behavior, laying behavior, movement within the aviary, and time spent in the different zones.…”

“…These nest behaviors help prevent laying eggs in the floor area (off-nest), which are prone to breakage, stained with hen droppings, laborious to collect, and often times contaminated with eggshell bacteria ( De Reu et al., 2006 ). Studying these new traits, Bécot et al. (2023) estimated heritabilities (standard errors ( SE )) of 0.13 (0.02), 0.54 (0.06), and 0.24 (0.04) for laying rate in the nest, mean laying duration and percentage of nests used, respectively.…”

Commercial laying hens exhibit long-term consistent individual differences and behavioural syndromes in spatial traits

“…smothered hens in overcrowded areas [ 56 ]) and production (e.g. eggs on the floor due to preferred nestbox being occupied [ 57 ]). Therefore, by understanding behavioural differences in commercial settings we can design appropriate management tools and breeding practices to improve animal welfare, such as sensors to detect pilling behaviours [ 56 ], practices to encourage earlier transitions between tiers after transfer to an aviary [ 58 ], and breeding hens for specific behaviour [ 17 , 57 ].…”

Floor eggs in goose breeders: patterns, genetic and environmental influences, and physiological indexes

“…However, there is also a study that fails to find this difference ( van den Oever et al, 2020 ). In addition to genetic differences, nest preferences, time spent in the nest, and floor-laying behaviors (nest box acceptance) are heritable within genetic strains ( Becot et al, 2021 ; Wolc et al, 2021 ; Bécot et al, 2023 ). The selection of different hen lines against undesirable traits is possible to achieve a reduction in the percentage of floor eggs ( Sørensen et al, 2017 ).…”