Welfare-Related Behaviors in Chickens: Characterization of Fear and Exploration in Local and Commercial Chicken Strains.

Abstract

Simple SummaryLocally adapted chicken strains are frequently discussed as a favorable alternative in poultry production. They might serve as dual-purpose and robust strains that have advantageous behaviors, such as exploration and reduced fear reactions, which might support animal welfare in general. Therefore, it is important to characterize welfare-related behaviors, such as fear and exploration, and to identify these behavioral traits among the diversity of chicken strains. The aim of this study was to characterize fear reactions and exploration based on the avoidance of a novel object and the avoidance of a human in three different chicken strains. To identify interesting alternatives for future poultry production, a layer hybrid (Lohmann Brown), a dual-purpose hybrid (Lohmann Dual) and a locally adapted strain (Rhinelander) were tested for their fear and exploration behavior towards unknown objects and humans. Results showed clear differences in fear and exploration between all three strains, regarding fear of objects and humans. The strain-specific results illustrate the high diversity of behavioral traits. The understanding of behavioral diversity, including fear and exploration, might contribute substantially to future breeding programs, including of commercial strains, and the preservation of local strains in general, which can improve animal welfare on a genetic and individual basis.Fear and exploration are crucial traits determining how animals behave in novel situations, and thus, they influence animal welfare. The aim of this study was the characterization of these behavioral traits among different strains to identify interesting alternatives for future poultry production. Whereas the Novel Object Test (NOT) focuses on fear and exploration of novel objects, the Avoidance Distance Test (ADT) addresses this in the context of humans. Here, a commercial hybrid line, a dual-purpose hybrid and a local adapted strain were tested. For the differences between strains and development of fear, Lohmann Brown (n = 714), Lohmann Dual (n = 844) and Rhinelander (n = 458) were observed weekly until maturity. Results show that fear and exploration towards unknown objects and humans are breed-specific (all p < 0.01). Additionally, development of fear in NOT and ADT differed between all three strains (both p < 0.01). The expressions of fear of humans or objects should be regarded as characteristics adapted for different husbandry systems and breeding goals, e.g., high exploratory behavior in aviary or high avoidance of predators in free-ranging husbandry or at least a balanced ratio between fear and exploration. Characterization of behavioral traits among different strains, understanding diversity and integrating these behaviors into future breeding and husbandry systems might reflect the need to preserve local strains and the potential to improve animal welfare.