The survival, growth, development, productivity and fertility of animals are a reflection of their health. Feed quality is the most important exogenous factor influencing animal health. Health and Food Safety concerns are putting pressure on better quality feed ingredients, which opens space in this market for microalgae biomass as nutritional supplement, as they posses many unique and interesting biochemical properties when compared to higher plants. Most of the raw materials currently used for animal feed products are higher plants as corn, soybeans, sorghum, oats, and barley. Beside the nutritional improvement that microalgae incorporation in feeds versus higher plants may bring to animals health, they are the only biomass material that allows production with daily harvest all year round. This could bring to the feed market more security of supply on raw materials.
The use of microalgae for animal feed started in the early 70s. Microalgal properties give them the ability to enhance feed nutritional content, improving their effect in animal health.
As for higher plants, the nutritional composition of microalgae is made up mainly of proteins, carbohydrates, lipids and trace nutrients, including vitamins, antioxidants, and trace elements. The reported nutritional composition of microalgae fits within the following ranges: 39-54% of proteins for marine microalgae and 10-71 % for freshwater microalgae, 8-64 % of carbohydrates and 2-22 % of lipids. All species have similar amino acids composition and are rich in the essential amino acids.
Since microalgae were initially utilized as supplements for animal nutrition, several studies have been performed on fish, farm animals and pets in order to evaluate microalgae potential as animal feed supplements, and their effects on the animal health, growth and nutritional properties. Although microalgae are able to enhance the nutritional content of conventional food preparations and hence, to positively affect the health of humans and animals, some constituents of microalgal biomass may represent constrains on its incorporation on feeds, like nucleic acids, toxins and heavy-metal components.
Feeds are blended from various raw materials and additives. These blends are formulated according to the specific requirements of the target animal, which need a variety of nutrients to meet their basic needs. They include carbohydrates, fats, fiber, proteins, minerals, vitamins and water. Regarding microalgae incorporation as feed supplements, prior to commercialization, algal material must be analyzed for the presence of toxic compounds to prove their harmlessness. The next step is to get approval for their incorporation as dietary supplements or additives. In order to achieve that approval, microalgae should satisfy the Safety and International Standards regulating feed production. The most relevant entity establishing feed safety international standards is IFIF - International Feed Industry Federation.
According to the WHO Food and Agriculture Organization, developing countries are on the verge of moving toward more meat and livestock production and consumption. There are several factors that will drive the global animal feed industry including population growth and incomes measured by growth in GDP, feed grain prices, health and food safety issues, and environmental issues. The future remains bright for the expansion of industrial feed as meat consumption in the developed world is expected to continue to increase in developing countries, with poultry meat leading this growth.