Cage-free environments expose hens to more disease-causing organisms due to increased contact with other birds, wild animals and bacteria. Studies indicate that mortality rates are generally higher in cage-free systems. This may lead to increased antibiotic use, raising concerns about antimicrobial resistance, which threatens both animal and human health. Since 90% of poultry diseases are linked to gut health, gut health management is crucial to mitigate disease and reduce the need for antibiotics.
Poultry Specialist
Alltech
The European egg industry is transitioning away from caged farming as the European Commission pushes for more humane practices. While a definitive timeline for a full ban remains unclear, many countries have already banned — or scheduled the phase-out of — cage systems. Luxembourg, Switzerland and Austria have already banned caged production, with Germany, Czechia and Slovakia planning to follow suit over the coming years.
Cage-free systems allow hens to express natural behaviors like wing stretching, walking, dust bathing and foraging, which are seen as welfare improvements. However, this shift also brings challenges, including higher disease exposure, increased production costs, and the need for better management of litter quality, aggression and feed efficiency. Proper biosecurity, nutrition and gut health management are essential to maintain productivity and food safety.
CHALLENGES IN CAGE-FREE EGG PRODUCTION
The transition to cage-free systems includes two main types of housing: barn and free-range systems. In barn systems, hens can move freely within the house and have access to perches and litter for dust bathing and scratching. Free-range systems offer additional access to outdoor areas covered in vegetation. However, this increased movement and exposure to the environment bring new concerns, particularly regarding disease control, feed consumption, wet litter management, and the potential rise in antibiotic usage.
Increased disease risk and antibiotic use
Cage-free environments expose hens to more disease-causing organisms due to increased contact with other birds, wild animals and bacteria. Studies indicate that mortality rates are generally higher in cage-free systems. This may lead to increased antibiotic use, raising concerns about antimicrobial resistance, which threatens both animal and human health. Since 90% of poultry diseases are linked to gut health, gut health management is crucial to mitigate disease and reduce the need for antibiotics.
Higher feed consumption and nutrient absorption
In cage-free systems, birds engage in more physical activities such as running, flying and foraging. This increased energy expenditure, which can be further increased by adverse weather conditions, means the bird must consume more feed to maintain productivity. Therefore, gut health is vital so that the surface available for digestion and absorption is optimal, allowing the bird to maximize feed utilization. If a hen’s gut is compromised due to an infection, feed utilization suffers, leading to decreased egg production and increased feed costs.
Wet litter issues
Another challenge in cage-free housing is the increased contact with litter, which can become wet due to digestive upsets, nutritional imbalances, disease or poor ventilation. Wet litter contributes to ammonia buildup, leading to footpad dermatitis, bumblefoot, and overall poor bird welfare. Digestive issues caused by conditions like coccidiosis or dysbacteriosis can further exacerbate wet litter problems, making gut health management a priority.
Egg safety and quality
When moving to a cage-free system, there is a higher risk of eggs being laid outside nesting areas or in dirty litter, and since hens have more contact with manure, eggs can be more prone to bacterial contamination. Reducing the risk of contamination needs a holistic approach including vaccination, biosecurity, gut health management, proper egg handling, and environmental controls.
MANAGING CAGE-FREE CHALLENGES THROUGH GUT HEALTH
A holistic approach is necessary to maintain hen health, productivity, welfare and food safety in the transition to a cage-free system. One effective strategy involves supporting gut health through yeast mannan-rich fraction (MRF). MRF promotes microbiota diversity, enhances pathogen resistance and strengthens gut integrity.
Direct pathogen control
One way to reduce disease risk and antibiotic use in cage-free systems is by preventing pathogen colonization in the gut. Pathogens like Salmonella adhere to the gut lining via type 1 fimbriae. MRF binds to these fimbriae, blocking bacterial attachment. Studies indicate that MRF supplementation in layer diets significantly lowers Salmonella prevalence in ovarian tissue and concentration in ceca, reducing the risk of eggshell contamination. By minimizing pathogen attachment, MRF also decreases gut inflammation and improves nutrient absorption, leading to better feed efficiency and overall bird health.
Gut microbiome and competitive exclusion
A diverse gut microbiota is essential for digestion, immunity and pathogen resistance. A well-balanced microbiota outcompetes harmful bacteria for nutrients and attachment sites, preventing pathogenic colonization. However, stressors which are more likely in a cage-free system, like environmental changes, can disrupt microbiota balance, leading to dysbiosis, reduced nutrient absorption and compromised gut integrity.
MRF supplementation promotes microbiota diversity, increasing beneficial bacteria like Lactobacillus and Blautia. This enhances competitive exclusion, where beneficial bacteria outgrow and suppress harmful pathogens, maintaining gut health. Additionally, MRF stimulates the production of short-chain fatty acids (SCFAs), which further support gut integrity and overall bird health.
Gut integrity
The transition to a cage-free system can have negative effects on feed efficiency. MRF has been shown to improve absorptive capacity through increasing villi height and surface area and improving villi-to-crypt ratio, enabling improved absorption of nutrients, which may help alleviate some of these negative effects.
CONCLUSION
The shift to cage-free egg production in Europe presents both challenges and opportunities. While improving hen welfare, cage-free systems do require enhanced management to mitigate disease risk, optimize feed efficiency and maintain egg safety. Gut health plays a critical role in addressing these challenges.
MRF supplementation offers a proactive solution to support microbiota diversity, prevent pathogen colonization and enhance feed efficiency. By prioritizing gut health, producers can navigate the complexities of cage-free production while ensuring high welfare standards, strong hen immunity and safer eggs for consumers.
About Dr. Harriet Walker
At the Alltech® Technology Group, Dr. Harriet Walker works as a poultry specialist. Within this role she provides technical support to the sales force and supports and interprets poultry research activities, focusing on providing solutions to optimize animal performance and efficiency.
Before taking this role, Harriet worked in the industry as a poultry nutritionist, developing a solid nutritional and technical knowledge base. She has extensive experience in bird nutrition and management over various farm sizes and poultry types.
Harriet completed her Ph.D. at Nottingham Trent University in 2013, evaluating the gut health and performance of broilers when feeding supplements to reduce antibiotic use, elucidating their mode of action. She also studied animal science at the University of Nottingham, where she completed her third-year dissertation in poultry nutrition in 2009.
