Layer hens will normally lay their eggs in an enclosed nest, perch, forage, and dust bathe [1, 2]. The ability to express these normal behaviours is important for layer hens to have good welfare.
In Australia, layer hens may be kept in caged (battery or furnished) or cage-free (aviary, barn, or free-range) housing systems. While there are advantages and disadvantages to all housing systems, caged systems, in contrast to cage-free housing systems, restrict and prevent hens from performing normal behaviours. Where hens are unable to perform normal behaviours, it can lead to increased levels of stress, frustration, and aggression.
Nesting
Layer hens normally perform nesting behaviours before and during egg laying, which is triggered by hormones at ovulation. Nesting behaviours include searching for a nest site, nest building, and laying eggs in a nest. Hens prefer laying eggs in enclosed nests with suitable friable substrates (e.g., straw or wood shaving) as nesting material [3–5]. Hens have consistently demonstrated through motivation tests that they are motivated to perform nesting behaviours and lay their eggs in an enclosed nest box if given the opportunity [2]. Hens denied the opportunity to nest can become frustrated, aggressive towards other hens, and perform abnormal behaviours, such as pacing and going through the motions of nest building. Hens provided with nests have been shown to have lower stress and fear levels, as well as perform fewer problematic behaviours towards other hens, such as injurious feather pecking and aggression [6–9].
Perching
Layer hen chicks begin trying to perch during the day at around 7-10 days of age and roost at night at around 3 to 6 weeks of age [10]. Having access to perches from a young age can be beneficial for musculoskeletal development and strength and helps improve the adaptability and navigational skills of hens [11–14]. While the preference and time of day hens choose to use perches differs depending on the breed, almost all hens appear to use perches at night for roosting if adequate perch space is provided [15–19]. In commercial farming systems, a minimum of 15cm of perching space per hen has been suggested to provide hens an opportunity to perch and roost which is based on the average body width of a hen [20, 21]. Being able to perch has also been shown to improve the plumage/feather condition, bone strength, and leg and foot health of hens [16, 22–26].
Dust bathing
Dust bathing involves hens crouching down and using their wings to throw dust/sand through their feathers before standing and shaking off the dust/sand. Layer hen chicks begin dust bathing during the first few weeks of life [10]. Dust bathing helps hens clean and maintain their feathers, remove oil build-up and parasites, and regulate their body temperature [2]. Hens appear to perform dust bathing in groups and most often in the middle of the day or early afternoon [27]. Hens require access to a suitable litter substrate for dust bathing and have shown a preference for substrates, such as sand and peat moss [28, 29].
Hens perform ‘sham dust bathing’ in some commercial farming systems, such as battery cages, where they are unable to dust bathe because of a lack of space and absence of suitable substrate [30]. Sham dust bathing involves hens pretending and going through the motions of dust bathing without the dust or suitable litter substrate being present. The occurrence of sham dust bathing may occur in hens not provided with access to litter substrates for dust bathing at an early age [31, 32]. Providing hens with suitable litter substrate for dust bathing within the first 4 weeks of life has been shown to help reduce the occurrence of severe and injurious feather pecking in a commercial flock [33–36].
Foraging
Foraging is a type of exploratory behaviour performed by hens, which involves scratching and pecking at the ground and in suitable litter substrates. Hens will forage even when feed is freely available and mainly forage during the morning and late afternoon [2, 10]. The quality and type of litter substate provided is important for encouraging and allowing hens to satisfy their foraging motivations. Similar to dust bathing, hens prefer a variety of different types of litter substrates when performing foraging behaviours [10, 28, 37]. The provision of a suitable substrate within the first 4 weeks of life for hens to forage can help reduce the occurrence of severe and injurious feathering pecking in a commercial flock [33–36].
What is the RSPCA’s view on the behavioural needs of layers?
Good animal welfare goes beyond preventing pain, suffering or distress and minimising negative experiences, and includes ensuring that animals can express their normal behaviours and have the opportunity for positive experiences. To provide layer hens with good welfare they should have the choice and opportunity to perform normal behaviours, such as stretching and flapping their wings, nesting, perching, dust bathing, and foraging.
The RSPCA is opposed to caged housing systems, such as battery cages, because they restrict or completely prevent hens from being able to move around freely and perform normal behaviours resulting in inherently poor welfare outcomes. To find out more about the RSPCA’s campaign to end battery cages, click here.
References
[1] Saxmose Nielsen S, Alvarez J, Joseph Bicout D, et al (2023) Welfare of laying hens on farm. EFSA Journal 21, e07789
[2] Hemsworth PH, Edwards LE, Hemsworth PH, Edwards LE (2020) Natural behaviours, their drivers and their implications for laying hen welfare. Anim Prod Sci 61:915–930
[3] Nicol CJ, Caplen G, Davies AC, Lambton J, Weeks S (2017) Farmed Bird Welfare Science Review.
[4] Hunniford ME, Mason GJ, Widowski TM (2018) Laying hens’ preferences for nest surface type are affected by enclosure. Appl Anim Behav Sci 201:7–14
[5] Hunniford ME, Widowski TM (2018) Curtained nests facilitate settled nesting behaviour of laying hens in furnished cages. Appl Anim Behav Sci 202:39–45
[6] Engel JM, Widowski TM, Tilbrook AJ, Butler KL, Hemsworth PH (2019) The effects of floor space and nest box access on the physiology and behavior of caged laying hens. Poult Sci 98:533–547
[7] Shi H, Tong Q, Zheng W, Tu J, Li B (2019) Effects of nest boxes in natural mating colony cages on fear, stress, and feather damage for layer breeders. J Anim Sci 97:4464
[8] Shi H, Li B, Tong Q, Zheng W, Feng G (2019) Influence of nest boxes and claw abrasive devices on feather pecking and the fear responses of layer breeders in natural mating colony cages. Appl Anim Behav Sci 220,104842
[9] Villanueva S, Ali ABA, Campbell DLM, Siegford JM (2017) Animal well-being and behavior: Nest use and patterns of egg laying and damage by 4 strains of laying hens in an aviary system. Poult Sci 96:3011–3020
[10] Skånberg L, Kjærsgaard Nielsen, CB, Keeling LJ (2021) Litter and perch type matter already from the start: exploring preferences and perch balance in laying hen chicks. Poult Sci 100:431–440
[11] Rentsch AK, Harlander A, Siegford JM, Vitienes I, Willie BM, Widowski TM (2023) Rearing laying hens: the effect of aviary design and genetic strain on pullet exercise and perching behavior. Frontiers in Animal Science 4,1176702
[12] Chew J, Widowski T, Herwig E, Shynkaruk T, Schwean-Lardner K (2021) The effect of light intensity on the body weight, keel bone quality, tibia bone strength, and mortality of brown and white feathered egg-strain pullets reared in perchery systems. Poult Sci 100,101464
[13] Widowski T, Torrey S (2017) Rearing young birds for adaptability. Advances in Poultry Welfare 49–76
[14] Campbell DLM, De Haas EN, Lee C (2019) A review of environmental enrichment for laying hens during rearing in relation to their behavioral and physiological development. Poult Sci 98:9–28
[15] Brendler C, Kipper S, Schrader L (2014) Vigilance and roosting behaviour of laying hens on different perch heights. Appl Anim Behav Sci 157:93–99
[16] Ali ABA, Campbell DLM, Karcher DM, Siegford JM (2019) Nighttime roosting substrate type and height among 4 strains of laying hens in an aviary system. Poult Sci 98:1935–1946
[17] Chen D, Bao J, Meng F, Wei C (2014) Choice of perch characteristics by laying hens in cages with different group size and perching behaviours. Appl Anim Behav Sci 150:37–43
[18] Dal Bosco A, Bist RB, Subedi S, Chai L, Regmi P, Ritz CW, Yang X (2023) Effects of Perching on Poultry Welfare and Production: A Review. Poultry 2023, Vol 2, Pages 134-157 2:134–157
[19] Campbell DLM, Makagon MM, Swanson JC, Siegford JM (2016) Perch use by laying hens in a commercial aviary. Poult Sci 95:1736–1742
[20] Riddle ER, Ali ABA, Campbell DLM, Siegford JM (2018) Space use by 4 strains of laying hens to perch, wing flap, dust bathe, stand and lie down. PLoS One 13, e0190532
[21] Giersberg MF, Spindler B, Kemper N (2019) Linear space requirements and perch use of conventional layer hybrids and dual-purpose hens in an aviary system. Front Vet Sci 6:471897
[22] Bhanja SK, Bhadauria P (2018) Behaviour and welfare concepts in laying hens and their association with housing systems. Indian Journal of Poultry Science 53, 1
[23] Neijat M, Casey-Trott TM, Robinson S, Widowski TM, Kiarie E (2019) Effects of rearing and adult laying housing systems on medullary, pneumatic and radius bone attributes in 73-wk old Lohmann LSL lite hens. Poult Sci 98:2840–2845
[24] Ali ABA, Campbell DLM, Siegford JM (2020) A risk assessment of health, production, and resource occupancy for 4 laying hen strains across the lay cycle in a commercial-style aviary system. Poult Sci 99:4672–4684
[25] Ali BA, Toscano M, Siegford JM (2019) Later exposure to perches and nests reduces individual hens’ occupancy of vertical space in an aviary and increases force of falls at night. Poult Sci 98:6251–6262
[26] Campbell DLM, Campbell DLM (2020) Skeletal health of layers across all housing systems and future research directions for Australia. Anim Prod Sci 61:883–892
[27] Grebey TC, Ali ABA, Swanson JC, Widowski TM, Siegford JM (2020) Dust bathing in laying hens: strain, proximity to, and number of conspecifics matter. Poult Sci 99:4103–4112
[28] Campbell DLM, Makagon MM, Swanson JC, Siegford JM (2016) Litter use by laying hens in a commercial aviary: dust bathing and piling. Poult Sci 95:164–175
[29] Ali ABA, Campbell DLM, Karcher DM, Siegford JM (2016) Influence of genetic strain and access to litter on spatial distribution of 4 strains of laying hens in an aviary system. Poult Sci 95:2489–2502
[30] Hemsworth PH, Hemsworth PH (2021) Cage production and laying hen welfare. Anim Prod Sci 61:821–836
[31] Wichman A, Keeling LJ (2008) Hens are motivated to dustbathe in peat irrespective of being reared with or without a suitable dustbathing substrate. Anim Behav 75:1525–1533
[32] Olsson IAS, Keeling LJ, Duncan IJH (2002) Why do hens sham dustbathe when they have litter? Appl Anim Behav Sci 76:53–64
[33] van Staaveren N, Ellis J, Baes CF, Harlander-Matauschek A (2021) A meta-analysis on the effect of environmental enrichment on feather pecking and feather damage in laying hens. Poult Sci 100:397–411
[34] Cronin GM, Glatz PC, Cronin GM, Glatz PC (2020) Causes of feather pecking and subsequent welfare issues for the laying hen: a review. Anim Prod Sci 61:990–1005
[35] Schreiter R, Damme K, von Borell E, Vogt I, Klunker M, Freick M (2019) Effects of litter and additional enrichment elements on the occurrence of feather pecking in pullets and laying hens – A focused review. Vet Med Sci 5:500–507
[36] Campbell DLM, De Haas EN, Lee C (2019) A review of environmental enrichment for laying hens during rearing in relation to their behavioral and physiological development. Poult Sci 98:9–28
[37] Oliveira JL, Xin H, Chai L, Millman ST (2019) Effects of litter floor access and inclusion of experienced hens in aviary housing on floor eggs, litter condition, air quality, and hen welfare. Poult Sci 98:1664–1677
