Laying hens and broilers have a fundamentally different digestive system, gut microbiome, and gut health profile, despite both being chickens. The difference lies in their production function: broilers are optimized for rapid growth, laying hens for long-term egg production. This has direct implications for how gut health is approached and supported in each type. In this article, we answer the most frequently asked questions on this topic.
What are the main anatomical differences in the digestive system of laying hens and broilers?
The digestive system of laying hens is relatively longer and heavier in proportion to their body weight than that of broilers. This gives laying hens more time and capacity to digest and absorb nutrients, which suits their longer productive life. Broilers have a more compact, faster-functioning digestive system geared toward high feed intake and rapid growth.
In broilers, the small intestine is relatively shorter relative to their final body weight, but the passage rate of feed is high. This makes efficient digestion per unit of time crucial. The proventriculus and gizzard are more heavily loaded in broilers due to intensive growth feeding, while laying hens follow a more regular feeding pattern.
Another important anatomical difference is the presence of medullary bone in laying hens. This calcium reservoir supports eggshell formation and places additional demands on calcium and phosphorus absorption in the gut. As a result, gut function in laying hens is not only directed at growth, but also at maintaining a constant mineral balance throughout the entire laying cycle.
How does the gut microbiome of laying hens and broilers differ?
The gut microbiome of laying hens is more stable and diverse than that of broilers, partly because laying hens go through a much longer production period. Broilers are typically slaughtered after 35 to 42 days, meaning their microbiome is still in full development. In laying hens, the microbiome has months to mature into a well-balanced composition.
A healthy microbiome is characterized by eubiosis: a stable, diverse community of bacteria dominated by beneficial groups such as Firmicutes and Bacteroidetes. In broilers, this balance is more fragile. The rapid growth, high nutrient density, and shorter age make the microbiome more susceptible to disruption, also known as dysbiosis. Dysbiosis is associated with an increase in pathogenic bacteria, often from the Proteobacteria group, and leads to inflammation and reduced gut integrity.
In laying hens, microbiome disturbances can occur during the transition from the rearing to the laying period, during heat waves, or with changes in feed composition. Because laying hens live longer, the cumulative impact of microbiome imbalance on production is also greater. A stable gut microbiome is therefore a long-term priority for laying hens, while in broilers it is more about rapid stabilization in the critical first weeks.
Which gut health problems are more common in broilers than in laying hens?
Broilers are more susceptible to coccidiosis, necrotic enteritis, and wet litter problems than laying hens. This is due to their rapid growth, high nutrient density, and the fact that their immune system and gut barrier are still fully developing during the short grow-out period.
Coccidiosis is one of the most impactful gut health problems in broilers. The parasite damages the intestinal wall, disrupts nutrient absorption, and makes the gut vulnerable to secondary infections. Necrotic enteritis, caused by Clostridium perfringens, often occurs as a complication following coccidiosis and can cause major losses in a short period of time.
Wet litter quality is another typical problem in broilers. When gut integrity decreases, water intake increases and moisture excretion via the manure rises. This increases the risk of footpad lesions and contact dermatitis. In laying hens this is less of an issue, although they can suffer from diarrhea and wet droppings during heat stress or microbiome disturbances, which negatively affects eggshell strength and egg production.
Why does feed composition have a different impact on gut health in laying hens versus broilers?
Feed composition has a different impact on gut health in laying hens than in broilers because the metabolic priorities are fundamentally different. Broilers need energy-dense, protein-rich feed for maximum muscle growth, while laying hens need feed that supports egg production, shell formation, and long-term gut integrity.
In broilers, the ratio of energy, protein, and amino acids is closely linked to gut health. An excessively high crude protein content increases fermentation in the hindgut, which can promote dysbiosis and necrotic enteritis. Methionine and the methionine-betaine interaction are particularly relevant here: a deficiency disrupts not only growth, but also gut barrier function.
In laying hens, calcium plays a central role. An insufficient calcium supply or poor calcium availability disrupts not only shell formation, but also affects gut pH and thereby microbiome composition. Moreover, laying hens respond differently to fiber-rich feed components: fibers support gut motility and microbiome balance, but an excessively high fiber content can limit energy intake and put egg production under pressure.
How does production age affect gut health in laying hens and broilers?
Production age has opposing effects on gut health in the two types. In broilers, gut vulnerability increases as they age within their short grow-out period, because rapid growth puts the gut barrier under pressure. In laying hens, gut health gradually declines as the laying cycle progresses, particularly in the mid- to late-lay phase.
Broilers are most vulnerable in the first two weeks of their lives. The gut barrier is not yet fully developed at that point and the immune system is still being built up. A good start, with attention to tight junction integrity and microbiome formation, largely determines the technical performance for the rest of the grow-out period.
In laying hens, the challenge is different. Older flocks, particularly after week 50 of the laying cycle, more frequently show a decline in eggshell strength, greater susceptibility to heat stress, and a less stable microbiome. The gut ages functionally, which reduces nutrient utilization. Targeted support in the mid- to late-lay phase is therefore essential to maintain production and quality.
Which supportive measures improve gut health in both poultry types?
Gut health in both laying hens and broilers rests on four pillars: mucosal barrier integrity, microbiome balance, immune modulation, and nutrient utilization. Measures that strengthen these pillars are applicable to both types, although the timing and dosage differ per production phase.
The following measures are scientifically substantiated and practically applicable:
- Betaine: strengthens tight junction proteins (occludin, claudin-1), protects the gut wall during heat stress and infection, improves villus height and crypt depth, and promotes eubiosis
- Organic acids: lower gut pH, inhibit pathogenic bacteria, and improve feed and water hygiene
- Slow-release butyrate: strengthens gut integrity and reduces gut inflammation
- MCFA (medium-chain fatty acids, C8-C12): have a strong antimicrobial effect against both gram-negative and gram-positive bacteria
- Yeast cell walls (beta-glucans and MOS): modulate the immune system and bind pathogens in the gut
- Phytogenic substances (essential oils): support gut flora and have anti-inflammatory properties
Drinking water is a particularly effective delivery vehicle for gut-supporting additives. Water intake is more reliable than feed intake during stress or illness, and dosage is fully flexible and controllable. More information about available drinking water and feed additives for poultry can be found on our product page.
How Jodoco helps with gut health in poultry
At Jodoco, we develop targeted solutions for gut health in both laying hens and broilers, based on more than 25 years of in-house research and collaboration with universities and institutes. Our approach combines multiple mechanisms of action in a single formula, tailored to the specific needs of each poultry type.
For poultry farmers who want to structurally improve gut health, we offer, among other things:
- Jodobet: natural betaine from sugar beets as an osmoprotectant, methyl donor, and gut barrier strengthener, for both laying hens and broilers
- Grovax: a combination of organic acids, slow-release butyrate, MCFA, and essential oils for improved gut health and technical performance, applicable via feed or drinking water
- Jodoplume: a specific product for laying hens that supports laying persistency, eggshell strength, and gut integrity, including in the mid- to late-lay phase
Our Grovax formula also fits perfectly into a “No Antibiotic Ever” strategy and helps reduce mortality under challenging farming conditions. Whether you work with broilers in an intensive system or with laying hens in a long-term production cycle, we are happy to think along with you about the best approach for your situation. Contact our team for personalized advice.
