Using microalgae products in swine diets

Why use microalgae in animal feeds?

A long-term agricultural challenge is achieving sustainability.

Microalgae could become a key feed ingredient, serving as a significant raw material for biofuel production and a nutrient source for animal feed.

The use of microalgae in animal systems could potentially reduce the carbon footprint in animal production by minimizing the land required for corn and soybean cultivation.

The various chemicals and functional nutrients present in microalgae make them a potential alternative to growth-promoting antibiotics in animal feed.

What are microalgae?

Microalgae are microscopic algae.

Algae are a class of organisms that live in water and convert sunlight to energy. Algae are more efficient than plants at this process, and some can double their biomass in a few hours.

This makes algae nature’s most efficient primary producers, and they account for more than 50 percent of global carbon fixation (carbon dioxide to organic compounds).

Microalgae species

There are thousands of different species of microalgae, which vary in nutritional composition. Examples of common microalgae species include

• Bacillariophyceae (part of phytoplankton)
• Clorophyseae (green algae)
• Cyanophyceae (blue-green algae)
• Chrysophyceae (golden algae)

Algae have the potential to enhance the quality of animal feed by serving as a nutritional supplement rich in desirable protein and other essential nutrients. However, further research on algae as a supplement in swine diets is needed, as different algal strains have different nutritional characteristics.

Harvesting and processing

Microalgae come from a variety of places including:

• Freshwater environments
  • Many are processed using fermentation tanks, which produce a lot of microalgae in a small amount of time
• Wastewater
  • These microalgae species don’t require fermentation and can simply be taken from wastewater
• Biofuel production systems
  • Defatted microalgae come from these systems. Defatting refers to the process of removing fat from the microalgae.

Nutritional potential in swine diets

Microalgae are a valuable and attractive feed supplement for livestock diets.

Several forms of microalgae were evaluated as feed supplements. These microalgae had crude protein (CP) levels ranging from 14% to 38.2%. At 38.2% CP, microalgae contain almost 4.5 times the amount of crude protein in different corn products.

Microalgae products are also high in the following.

• Fat content, which ranges from 1.5% to 9.3%
• Beneficial omega-3 fatty acids
• Vitamins
• Minerals
• Fibers
• Other bioactive compounds

University of Minnesota mouse models have demonstrated that the nutrient content of microalgae can induce changes in metabolism. These changes suggest that feeding pigs microalgae may help increase antioxidant defense and growth.

Some microalgae contain sugars (beta-glucans) that are beneficial to the pig’s gut, especially immature pigs, as their guts are still developing. Gut development is extremely important to the overall health and growth of the animal.

Experiments suggest that incorporating microalgae into animal diets is promising. However, we need more information before widespread use of microalgae occurs in animal feeding programs.

Further research should look at:

• Bioavailability of the nutrients: How available are the nutrients to pigs after eating the microalgae?
• Digestibility: Are microalgae easy for the pig to digest?
• Potential toxin levels: Is there enough toxin present to harm the pig?

These aspects of feeding microalgae are key to accurately formulating diets for growing pigs.