Seaweed in poultry nutrition: a sustainable strategy that improves the quality of the final product.
The use of seaweed in poultry feed has been gaining attention due to its nutritional benefits and its positive impact on bird health.
The growing interest in the use of seaweed in poultry nutrition stems from its diverse nutritional profile, as it contains a rich variety of proteins, lipids, amino acids, vitamins, minerals, and antioxidants, positioning it as a versatile ingredient for feed formulations.
As an ingredient rich in various nutrients, seaweed can be added to the diet as a partial or total substitute for conventional ingredients such as corn and soybean meal.
It contributes to more sustainable feeding practices because its production requires small areas and minimal land-based resources, while also helping to capture more carbon dioxide from the atmosphere.
• With the growing interest in more eco-friendly and nutritious feed alternatives, the use of seaweed in poultry nutrition represents an innovation and a promising strategy for the poultry industry.
One of the main highlights of incorporating macroalgae and microalgae into poultry diets is their high protein content. Microalgae varieties such as Spirulina and Chlorella can contain protein levels as high as 50–70%, surpassing traditional sources like soybean meal.
In addition, seaweed can be supplemented in the form of pellets or liquid extracts, which can be added to the birds’ drinking water. Among the microalgae used in animal production, Spirulina (Arthrospira sp.), Chlorella sp., and Schizochytrium sp. are the most commonly used.
Algae are defined as aquatic organisms belonging to the kingdom Protista, and they can be multicellular, presenting various forms and sizes. Seaweed is classified into different groups, including:
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Chlorophyta (green algae),
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Phaeophyta (brown algae),
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Rhodophyta (red algae), and
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Cyanophyta (blue-green algae or cyanobacteria).
Main Types of Algae
[register]Chlorophyta, or green algae, are rich in chlorophyll, which helps with detoxification, aiding the elimination of accumulated toxins in the birds’ bodies and promoting better digestion.
Additionally, they are a source of high-quality plant proteins and essential amino acids such as lysine, methionine, threonine, and valine, which are crucial for the growth and muscle maintenance of poultry and are considered limiting amino acids for birds.
• They provide high concentrations of calcium, which is crucial for bone development and eggshell health, as well as iron, which aids in oxygen transport in the blood and helps prevent anemia.
Additionally, their high cellulose content serves as dietary fiber, helping to regulate intestinal transit and promote gastrointestinal health.
They are rich in vitamin A, which supports eye health, feather growth and development, and helps maintain the integrity of mucous membranes and skin; vitamin C, which neutralizes free radicals in the birds’ bodies; and vitamin K, folic acid, and B12, which assist in the production of blood cells.
| The main carotenoids are lutein and zeaxanthin, which are antioxidants that protect cells from damage caused by free radicals, especially in birds exposed to environmental or heat stress. |
These polysaccharides can act as anti-inflammatory and immunomodulatory agents, helping to strengthen the birds’ immune system. The most commonly used green algae in poultry feed are Chlorella sp., Ulva sp., Volvox sp., and Cladophora sp..
Feeding broiler chickens with the freshwater green microalgae Chlorella vulgaris at 1.55 g/kg improved growth performance and breast meat yield.
Phaeophyta, or brown algae, contain high concentrations of iodine, alginic acid, fiber, and carbohydrates.
Iodine is an essential mineral for the proper functioning of the thyroid gland, which regulates the birds’ metabolism, helping to maintain hormonal balance and promote overall health. It can be especially beneficial for birds during periods of increased metabolic demand, such as reproduction or moulting.
Alginic acid is a substance with gelling properties that can aid digestion by promoting the elimination of toxins in the birds’ intestinal tract, acting as a natural pH regulator in the gut.
The primary form of energy storage in brown algae is laminarin (a polysaccharide), which birds do not fully digest; however, it can still serve as a source of energy for them.
The main brown algae used are Fucus vesiculosus, Ascophyllum nodosum, Laminaria, and Sargassum. When dried seaweed meal from F. vesiculosus was used in laying hens’ diets, an increase in crude protein and carotenoid content in the egg yolk was observed.
Additionally, a significant decrease in liver crude fat levels was observed, along with an increase in erythrocyte count, hemoglobin, and hematocrit levels (Buryakov, 2023).
| Rhodophyta, or red algae, are rich sources of essential fatty acids, such as omega-3—particularly eicosapentaenoic acid (EPA)—and omega-6, which help maintain cellular health and improve the lipid profile of birds. |
The consumption of these fatty acids by laying hens can contribute to improving eggshell quality, making the shells stronger and more durable, while also reducing the lipid content of the yolk and increasing the protein and omega-3 content in the yolk.
Another benefit of Rhodophyta is their high antioxidant content, including vitamin C, vitamin E, and polyphenols, which help to strengthen the birds’ immune system, making them more resistant to diseases and infections.
Red algae are rich in phycobiliproteins, which include pigments such as phycocyanins and phycoerythrins. These pigments not only give the algae their red coloration but also possess antioxidant, anti-inflammatory, and immunomodulatory properties.
• Accordingly, phycocyanins have been linked to benefits such as enhanced immune function and protection against oxidative stress, helping to reduce cellular damage in birds and contributing to their overall health.
Alginic acid, on the other hand, has detoxifying effects and can aid in the elimination of heavy metals and toxins from the birds’ bodies. The most commonly used algae from this group in poultry feed is Porphyra (also known as nori).
• When using aqueous extracts of Porphyra dioica to evaluate the delay of spoilage and oxidation in chicken breast during storage, it was observed that the treated chicken breasts showed lower lipid oxidation levels, reduced bacterial growth, and greater color stability compared to the untreated group (Reboleira et al., 2020).
| Cyanophyta, or blue-green algae, stand out due to their high protein and chlorophyll content, as well as bioactive compounds that promote digestive and respiratory health. |
They contain about 50-70% protein on a dry matter basis, making them an excellent source of plant protein, with high levels of essential amino acids such as lysine, methionine, and leucine, which are important for the growth and maintenance of muscle tissues.
• Cyanophyta contain essential fatty acids, including polyunsaturated fatty acids such as omega-3 (linolenic acid) and omega-6.
Cyanophyta contain polysaccharides such as cyanophyco-cellulose, which have prebiotic effects. These compounds promote the growth of beneficial bacteria in the birds’ intestinal tract, enhancing digestive health and efficient nutrient absorption.
The main blue algae used in poultry feed are Spirulina (Arthrospira platensis and Arthrospira maxima), Aphanizomenon flos-aquae, and Nostoc.
Spirulina platensis at 0.25–1.0% in broiler chicken diets significantly improved growth performance, including body weight, weight gain, and feed conversion rate (Park et al., 2018).
The use of marine algae in poultry feed represents a promising and sustainable strategy to improve the nutritional quality of feed and promote poultry health.
Incorporating seaweed into poultry diets can decrease the reliance on traditional ingredients like soybean meal and diversify feed sources.
Due to the wide range of species with distinct nutritional and functional benefits, seaweeds serve various purposes in poultry nutrition, helping to enhance meat and egg production efficiency while supporting bird health and sustainable farming practices.
References available upon request. [/register]