Strategies to Improve Chicken Welfare Through Enhanced Free Range Systems

Introduction

Animal welfare-friendly systems are linked to higher perceived product quality, for which some consumers are willing to pay more (Meluzzi and Sirri, 2016; Dal Bosco et al., 2014). Free-range chickens tend to express normal behaviour, improving their welfare and productivity (Vieira Rios et al., 2020). However, chickens on free-range farms often take 3 to 5 days to start using the outdoor range after pop-holes open due to the contrast between indoor and outdoor environments (Taylor et al., 2017, 2023). Many chickens stay near their sheds and do not use the outdoor space effectively (Figure 1; Weeks et al., 1994; Dawkins et al., 2003). This suggests they are not motivated to explore, making them "free-range" in name only. Low outdoor range use can lead to feather pecking and crowding, causing smothering (birds mass together, often on top of each other, resulting in death from suffocation) (Bestman et al., 2017). To address this, it is important to improve the design of the outdoor environment (Taylor et al., 2023) and provide enriching activities that are positive, productive, interesting, and challenging to stimulate natural behaviours (Schaeffer, 2012; Rana et al., 2022). There is growing recognition of the importance of outdoor access for chickens, with considerable variation in farm design and management. Providing access to the range environment could increase exploration, activity levels, and ranging behaviour in meat chickens and is, therefore, likely to improve chicken welfare (Taylor et al., 2017).

Figure 1. Shows that many chickens remain close to their sheds or pop-holes

Free Range Meat Chickens

Free-range meat chicken production aims to let chickens access outdoor areas to exhibit natural behaviours (Stadig et al., 2017). The recent increase in the free-range production system has been driven by consumer perceptions, as mentioned above, that these chickens live more natural and happier lives and that their meat is of a higher welfare standard than chickens reared in other systems (Rondoni et al., 2020). However, chickens sometimes hesitate to venture outside or only use certain areas of the range closer to the pop-holes (Figure 1; Chielo et al., 2016; Hartcher et al., 2016; Larsen et al., 2017). Initially, few birds use the range, but this increases over time (Campbell et al., 2020). Reducing this delay (latency) can increase range use. Chickens are more active in the early morning and late afternoon, avoiding midday heat (Chielo et al., 2016; Larsen et al., 2017).

Conventional and Furnished Cages

While conventional and furnished cages allow some natural behaviours and protect chickens from cannibalism and the spread of disease (Wurtz et al., 2019), limited space can affect chicken welfare (Rodriguez-Aurrekoetxea et al., 2014). 

Enrichment Strategies for Animals

Enrichment should make environments complex, varied, and engaging (Taylor et al., 2023; Veissier et al., 2024) and should be designed to improve captive animals' welfare and cognitive abilities (Veissier et al., 2024).  Enrichment can be:

• Sensory
• Physical
• Social
• Occupational
• Feeding-based
• Or a mix of these

Behavioural Enrichment

Enrichment should be positive, productive, interesting, and challenging, encouraging natural behaviours (Schaeffer, 2012). It should also allow birds to express normal behaviours as outlined in the Five Freedoms report by Brambell (Scarlett et al., 1999).

1. Freedom from hunger and thirst
2. Freedom from discomfort
3. Freedom from pain, injury, or disease
4. Freedom to express normal behaviour
5. Freedom from fear and distress

Early life experiences and their impact on the ranging behaviour of meat chickens

Early access to the ranging environment can significantly influence the ranging behaviour of chickens later in life. Research indicates that chickens exposed to outdoor ranges early on are more likely to explore and utilize these areas as they mature (Taylor et al., 2023). This early exposure helps them adapt to the complexities of the outdoor environment, reducing fear and anxiety and increasing positive behaviours and overall activity levels (Taylor et al., 2023). 

Additionally, providing visual access to the range from a young age and providing indoor panels and perches has been shown to decrease the latency to access the range and increase the time spent outdoors (Taylor et al., 2020). These findings suggest that early environmental experiences may play a crucial role in shaping the behaviour and welfare of free-range chickens (Figure 2). 

Figure 2: Early life experiences influence the ranging behaviour and welfare of chickens 

Factors Influencing Range Use by Free Range Chickens

Range use is often reported to be low in commercial flocks. Studies have shown that chickens often stay close to the shed, leading to high stocking density and soil erosion near the pop-holes, while outer areas of the range remain underused (Figure 1; Chielo et al., 2016; Larsen et al., 2017). Chickens near the coop are more likely to come into contact with their waste. This can lead to higher incidences of infections and infestations from parasites, which can compromise the overall health and productivity of the flock (Gadzama, 2024).  Little is known about the adverse conditions around pop-holes that hinder chickens from going out. However, pop-hole size and number have been indicated as possible impediments to range access (Larsen et al., 2017; Campbell et al., 2018). Furthermore, increased solar radiation (0 to 1.01 kW/m2) and wind speed (0 to 5.5 m/s) were shown to reduce range use by chickens (Stadig, 2017). The distribution of chickens in the range depends on features like vegetation and shelters (Figure 3; Larsen et al., 2017). Attractive ranges with natural or artificial shelters increase range use and protect from predators and intense sunlight (Nagle & Glatz, 2012). Chickens avoid intense ultraviolet (UV) radiation, which can be harmful (Rana et al., 2021). 

Factors that affect daily outdoor range use

1. Range design (Campbell et al., 2020)
2. Weather condition
3. Season
4. Time of day
5. Range enrichments

Pop-holes (shed openings)

To encourage chickens to use the range, ensure there are enough pop-holes (shed openings) for easy access to the outdoor environment (Gilani et al., 2014). 

Enhancing the range Area 

Chickens need cover from aerial predators, so improving the outdoor environment by providing features such as trees, shrubs, shade cloths, and shelters could provide shade, protection from predators, and interesting areas for the chickens to explore (Bestman & Bikker-Ouwejan, 2020; Gadzama, 2024). In addition, birds should be protected from ground predators by fencing the range area. Enriching the range with vegetation (Figure 3), logs, and dustbathing areas could make the range area more attractive and safer, encouraging chickens to venture further from the shed or coop (Nagle & Glatz, 2012; de Koning et al., 2018). Complex environments may reduce anxiety and increase positive behaviours (Taylor et al., 2023). 

Advantages of free-range system 

The free-range system can improve welfare and enhance poultry product quality by increasing exercise, reducing stocking density, and expanding the activity space (Semwogerere et al., 2018). Free-range systems improve slow-growing broilers' nutritional, food safety, and sensory properties (Vanhonacker & Verbeke, 2014). Slow-growing, free-range chickens are more likely to meet consumer expectations for organic products because they exhibit less fat, have better flavours, and contain more polyunsaturated fatty acids (PUFAs) (Wang et al., 2009). Bogosavljević-Bošković et al. (2012) reported that free-range poultry products are superior to cage-reared products in tenderness and meat quality due to lower subcutaneous and abdominal fat levels. Compared to caged chickens, free-range chickens develop better meat quality, gait scores, and weather conditions, as well as a richer microbial composition (Chen et al., 2018).

Figure 3: Free-range meat chickens

Advantages of free-range poultry farming systems

1. Birds have access to outdoor spaces
2. Natural sunlight
3. Freedom to move
4. Have more space for social interactions
5. Ability to express natural behaviours 
6. Reduced plumage damage 
7. Reduced footpad dermatitis 

Some Risks Associated with free-range system

1. Parasitic infections
2. Exposure to disease
3. Heat stress
4. Predation. 

Effects of the rearing system on chicken meat quality

The quality of poultry products depends on genotype, rearing system, and the environment (Zhang et al., 2022). Different rearing systems used for animals can affect welfare, growth performance, meat quality, stress resistance, and product price (Bai et al., 2022; Gadzama, 2024).

Factors that affect the meat quality of broilers include

• Rearing systems (Intensive, semi-intensive, or extensive) 
• Rearing environment
• Climatic conditions
• Physical exercise
• Final slaughter weight and age

Conclusion

Chickens provided with outdoor access often do not fully utilize the range area, which can lead to several welfare issues. Providing chickens with a complex rearing environment may reduce anxiety and increase positive behaviours. By enhancing the free-range environment, we can ensure that it meets both the welfare expectations of consumers and the natural needs of the chickens. Still, more research is needed to find the best practices for improving range use and chicken welfare.

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