Researchers tested whether a type of green algae called spirulina could improve the health and egg production of laying hens. They fed 160 chickens different amounts of spirulina mixed into their regular food for several weeks. The results showed that hens eating spirulina laid more eggs, produced larger eggs with better shells, and had stronger immune systems compared to hens eating regular food. The spirulina also appeared to improve the fat content in the eggs and had powerful antioxidant properties—similar to vitamins C and E. This suggests spirulina could be a natural, healthy addition to chicken feed that benefits both the birds and the eggs they produce.

The Quick Take

  • What they studied: Whether adding spirulina (a nutrient-rich green algae) to chicken feed could improve egg production, egg quality, and chicken health
  • Who participated: 160 laying hens divided into four groups: one control group eating regular food and three groups eating food with different amounts of spirulina added (1.5, 3, or 4.5 grams per kilogram of feed)
  • Key finding: Hens fed spirulina laid more eggs (92.9-94.5% laying rate versus lower in control), produced heavier eggs (62.2-67.1 grams), had better shell quality, and showed stronger immune responses with statistically significant improvements (P < 0.05)
  • What it means for you: If you raise chickens or consume eggs, spirulina supplementation appears to be a safe, natural way to improve egg production and quality. However, this research is specific to chickens and doesn’t directly apply to human health, though it suggests spirulina has beneficial properties worth studying further in other contexts

The Research Details

This was an experimental study where researchers divided 160 laying hens into four equal groups. One group (the control) ate standard chicken feed with no additions. The other three groups ate the same feed but with spirulina powder mixed in at three different amounts: a low dose (1.5 grams per kilogram), a medium dose (3 grams per kilogram), and a high dose (4.5 grams per kilogram). The researchers then measured and compared egg production, egg quality, chicken health markers, and blood chemistry across all four groups over the study period.

The researchers used several scientific methods to measure results. They counted how many eggs each hen laid and weighed them. They examined egg shells and yolk color. They tested the chickens’ immune response by measuring antibodies against Newcastle disease (a common chicken illness). They also analyzed blood samples using advanced laboratory techniques to measure fatty acids and cholesterol levels. Finally, they tested spirulina in a laboratory dish to measure its antioxidant power—essentially its ability to protect cells from damage.

This type of controlled experiment is valuable because researchers can carefully control all variables except the spirulina dose, making it easier to see if spirulina actually caused the improvements observed.

This research design matters because it uses a controlled comparison (control group versus treatment groups) which helps prove that spirulina caused the improvements, not other factors. By testing three different doses, researchers could also determine which amount works best. Testing both the living animals and laboratory samples of spirulina provides multiple types of evidence supporting the same conclusion.

Strengths: The study used a reasonable sample size (160 hens), included a proper control group, tested multiple doses to find optimal levels, and used multiple measurement methods (egg production, immune markers, blood chemistry, and laboratory antioxidant tests). Weaknesses: The study was conducted only in chickens, so results may not apply to other animals or humans. The paper doesn’t specify the exact duration of the study or provide detailed statistical analysis methods. This is a single study, so results should be confirmed by other independent researchers before drawing firm conclusions.

What the Results Show

Hens that ate spirulina-supplemented feed significantly outperformed the control group in multiple ways. Laying rate (the percentage of days a hen produces an egg) increased to 92.9-94.5% in spirulina-fed groups compared to the control group. Egg weight increased to 62.2-67.1 grams in treated groups, and overall egg mass (total weight of eggs produced) improved. The yolk color became more vibrant and appealing, and shell quality improved—meaning stronger, better-formed shells.

The immune system benefits were also notable. When researchers measured antibodies against Newcastle disease (a marker of immune strength), hens fed spirulina showed significantly higher antibody levels, particularly those receiving the lower and medium doses (1.5 and 3 grams per kilogram) during the first 60 days of the study. This suggests spirulina helped the chickens’ bodies fight off potential infections more effectively.

Feed conversion ratio—a measure of how efficiently hens convert food into eggs—also improved with spirulina supplementation. This means the hens needed less feed to produce the same amount of eggs, which is economically important for farmers.

Blood chemistry analysis revealed that spirulina changed the fatty acid profile in the hens’ blood in beneficial ways. The levels of healthy unsaturated fats increased while cholesterol levels decreased—changes that would be considered positive in human health as well.

Laboratory testing of spirulina itself showed it has powerful antioxidant properties—meaning it can neutralize harmful molecules called free radicals that damage cells. The antioxidant activity was comparable to well-known antioxidant vitamins C and E, especially at the higher spirulina doses (3 and 4.5 grams per kilogram). This suggests spirulina works as a protective compound within the chicken’s body, reducing cellular damage from normal metabolism and stress.

This research aligns with previous studies suggesting that spirulina and other algae-based supplements can improve animal health and production. The findings support the growing body of evidence that natural, plant-based additives can enhance both performance and health markers in livestock. However, most previous research on spirulina has focused on human health or fish farming, so this chicken-specific study adds valuable new information to the field.

This study was conducted only in chickens, so we cannot assume the same results would occur in other animals or humans. The researchers don’t specify exactly how long the study lasted, which makes it harder to understand the timeline of benefits. The study doesn’t describe the chickens’ living conditions, diet quality, or other environmental factors that might affect results. Additionally, this is a single study from one research group—the findings should be confirmed by other independent researchers before being widely adopted. The study also doesn’t examine whether spirulina supplementation has any negative effects or whether benefits persist long-term after supplementation stops.

The Bottom Line

For chicken farmers: Spirulina supplementation at 1.5 to 3 grams per kilogram of feed appears to be a safe, effective way to improve egg production and quality (moderate confidence level—based on one well-designed study). The medium dose (3 grams per kilogram) seems to offer the best balance of benefits. For consumers: Eggs from spirulina-fed hens may have improved nutritional profiles with better fatty acid composition, though more research is needed to confirm human health benefits (low to moderate confidence—based on animal data only).

Chicken farmers and egg producers should care about this research because it offers a natural way to improve productivity and egg quality. Consumers interested in higher-quality eggs may want to seek out eggs from spirulina-supplemented flocks if available. People interested in natural animal nutrition and sustainable farming practices would find this relevant. However, this research doesn’t directly apply to human nutrition—people shouldn’t assume that taking spirulina supplements will have the same effects it has in chickens.

Based on the study, improvements in egg production and immune response appeared within the first 60 days of spirulina supplementation. Optimal results seemed to occur with consistent supplementation over several weeks. If supplementation were stopped, benefits might diminish over time, though this wasn’t specifically tested in this study.

Want to Apply This Research?

  • If you raise chickens, track daily egg production count and average egg weight weekly. Compare these metrics before and after introducing spirulina supplementation, noting the specific dose used and date started.
  • For chicken owners: Calculate your current feed costs and egg production rates, then gradually introduce spirulina at the recommended dose (start with 1.5 g/kg) while maintaining detailed records of changes in laying rate and egg quality over 8-12 weeks.
  • Establish a baseline of your current egg production and quality metrics (eggs per day, average weight, shell strength, yolk color). After introducing spirulina, measure the same metrics weekly for at least 12 weeks. Track feed costs to calculate return on investment. Monitor chicken health indicators like activity level and disease incidence to ensure no negative effects occur.

This research specifically studied laying hens and does not directly apply to human health or nutrition. While spirulina shows promise as a poultry feed supplement, this is a single study and results should be confirmed by additional research before widespread adoption. Chicken farmers considering spirulina supplementation should consult with a veterinarian or poultry nutritionist to ensure it’s appropriate for their specific flock and farming conditions. This information is for educational purposes and should not replace professional veterinary or nutritional advice. Consumers should not assume that eggs from spirulina-supplemented hens will provide the same benefits that spirulina might provide if consumed directly, as the effects may differ significantly between species.