Behavioral needs of chickens: Dustbathing

This issue will cover:

-What are behavioral needs?

-What is dustbathing?

-Dustbathing in commercial housing systems

Substrate preferences

Enriched cages

-Can dustbathing control ectoparasites?

Behavioral needs encompass behaviors that chickens are strongly motivated to perform, and if they are unable to perform these highly motivated behaviors it could result in frustration (Duncan, 1998). Behavioral needs are commonly driven by a strong internal motivation, such as hormonal or neuronal triggers, resulting in the behavior being performed in all environments regardless of whether the behavior can be performed satisfactorily (Duncan, 1998). When chickens are unable to fulfill these behavioral needs, they can exhibit a rebound (increase) in the limited behavior once they can perform it again. Known behavioral needs of chickens include foraging, preening, and nesting. Dustbathing is also considered a behavioral need despite the behavior being controlled by a combination of internal (circadian rhythm) and external factors (presence of substrate). Dustbathing occurs in all chicken housing systems, even in caged systems where there is no access to friable substrate (Duncan, 1998).

What is dustbathing?

Dustbathing is performed by many wild and domestic birds and functions to remove stale lipids from the feathers and remove ectoparasites (Duncan, 1998). Dustbathing typically occurs every other day and lasts approximately 27 minutes per bout (Vestergaad, 1982). When birds are unable to dustbathe, a buildup of lipids and degradation of feather structure occurs. This is reversable when given an appropriate substrate (van Liere et al., 1987). For example, when placed on wired floors for several days chickens will exhibit a rebound effect when given access to substrate (straw) again (Vestergaard, 1982). This means that they began dustbathing sooner and for longer when moved from wired floors to substrate compared to chickens that had daily access to substrate. Therefore, dustbathing is essential to maintain good feather condition.

Steps in the dustbathing behavioral sequence

Behavioral needs of chickens: Dustbathing - Image 2

Dustbathing in commercial chickens

Dustbathing can be observed to some extent in all commercial housing systems. In the absence of appropriate substrates, chickens perform incomplete dustbathing called “sham dustbathing” (Vestergaard, 1998). However, sham dustbathing does not diminish the motivation to dustbathe like a complete sequence of dustbathing does (Olssen et al., 2002). Therefore, only the provision of appropriate substrates can fulfill the behavioral need to dustbathe.

Substrate preferences

-Laying hens prefer peat moss and sand over wood shavings and straw for dustbathing (Petherick and Duncan, 1989, van Liere et al., 1990)

-In laying hens, after litter deprivation, dustbathing increases in sand but not in wood shavings (van Liere et al., 1990)

-As long as it is friable, used wood shavings are more attractive to laying hens for dustbathing than fresh wood shavings (Moesta et al., 2008)

-Broilers choose to dustbathe in sand over rice hulls, wood shavings and shredded paper (Shields et al., 2004), as well as peat moss and fine straw over wood shavings, coarse straw and bark (Holt et al., 2023)

Enriched cages

-When given a choice, laying hens preferentially sham dustbathe on AstroTurf over wire, rubber, and slatted floors (Merrill et al., 2006)

-Sham dustbathing usually occurs close to feeders and hens will bill rake in the feed trough in an attempt to spread feed (Lindberg and Nicol, 1997)

-Sham dustbathing can result in feather and foot damage (Duncan, 1998)

-Feed can be provided on scratch mats in enriched cages to encourage dustbathing and foraging

Behavioral needs of chickens: Dustbathing - Image 3

Dustbathing for ectoparasite control?

Ectoparasites, such as the red mite and northern fowl mite, present welfare concerns for chickens. Mite infestation can result in reduced weight gain, anemia, and, in extreme cases, death (Kilpinen et al., 2005). In response to ectoparasites, chickens spend more time preening, head scratching, and dustbathing (Kilpinen et al., 2005; Murillo et al., 2020). Additionally, dustbathing in diatomaceous earth, sulfur, and kaolin (fine clay) reduces northern fowl mite presence by 80-100% within one week (Martin and Mullens, 2012). However, dustbathing in sand does not decrease ectoparasites, and dustbathing in feed increases ectoparasite load (Vezzoli et al., 2015). Consequently, dustbathing only mitigates ectoparasite load when the substrate has drying effects. For more information on poultry ectoparasites see vol. 15 “Poultry parasites: bed bugs” and vol. 17 “Poultry parasites: Northern fowl mites.”

Behavioral needs of chickens: Dustbathing - Image 4

Summary

-Dustbathing is a behavioral need that is crucial for feather maintenance

-Chickens prefer to dustbathe in fine particle substrates (e.g., peat, sand, fine straw) over coarse substrates (e.g., coarse straw, bark, wood shavings, rice hulls)

-Substrates must be friable for chickens to satisfy the need to dustbathe

-Dustbathing helps to maintain feather condition and, depending on the substrate, can reduce ectoparasite infestations

This article was originally published on Poultry Extension Collaborative (PEC) and it is reproduced here with permission from the authors.