Two of the most essential protein sources to the animal feed
industry - fishmeal and soy - are also two feed ingredients sometimes criticised as
Even those who fiercely defend the two industries will
generally admit that a significant increase in output would require disrupting
highly sensitive ecosystems from the ocean to the rainforests.
Therefore, it is widely accepted that the feed of the future
will need to be able to draw on a much wider array of protein sources.
Feed vs food tensions
There are many of these available, ranging from legumes to animal
byproducts. However, this article will focus on two of the less-well-understood
sources of alternative proteins - algae and methanotrophic bacteria.
These two have the advantage of not pitting human
consumption and animal feed consumption against each other, as neither is a
primary source of calories for humans (unlike, say, wheat).
Moreover, their production would probably not require use of
high value farmland.
Therefore, they may both have a part to play in helping us
feed a growing world population on static levels of fertile land.
Algare actually a heterogeneous mix of organisms, and for
feed purposes researchers are investigating a wide array, from single-celled
microalgae, such as Chlorella, to
macroalgae (seaweed) such as Ascophyllum
Protein, fat and (carbohydrate) levels in various algae and crops
Spirogyra: 16-25, 11-21, (33-64)
Anabaena cylindrical: 43-56, 4-7, (25-30)
Chlorella vulgaris: 51-58, 14-22, (12-16)
Spirulina: 60-71, 6-7, (13-16)
Soybean: 37, 20, (30)
Corn: 10, 4, (85)
Wheat: 14, 2, (84)
Figures show % of dry matter. Source: FeedInfo
Algae is increasingly seen as a key solution to the protein
problem, as many species provide an excellent protein yield per unit of land.
According to research by Stephen Bleakley and Maria Hayes,
seaweed, at 2.5-7.5 tonnes per hectare per year, and microalgae, at 4-15 tonnes
per hectare per year, have "higher protein yield per unit area", than conventional
crops such as soybean, pulse legumes, and wheat.
These have protein yields of at best 2 tonnes per hectare
(although total crop yield may, of course, be larger).
Spirulina algae have protein levels of 60-71 grammes of
protein per 100 grammes.
Importantly, algae also generally contain all the essential
amino acids, making them appealing replacements to proteins such as fishmeal,
although in a literature review, Mark Wells and fellow academics point out that
many nutritional factors of algae including amino acid levels may vary
depending on the coastal conditions in which they are grown and the season in
which they are harvested.
Moreover, beyond simply their high protein and interesting
amino acid profile, algae also bring additional nutritional benefits.
Polyunsaturated fatty acids, including omega-3 fatty acids,
vitamins, minerals, antioxidants, and natural colorants are all found at high
Certain algae, such as Chlorella, have been determined to
increase gut health and immune status too.
It has even been
found that inclusion of seaweed into ruminants' diets can reduce methane
emissions dramatically, hinting at a potential solution to reduce the
greenhouse gas footprint of the livestock sector.
As photosynthesisers, algae also contribute to the fight
against greenhouse gases by consuming carbon dioxide as they grow.
'Tip of the spear'
Indeed, Dr Matt Carr of the US's Algae Biomass Organization
told Feedinfo News Service he believes these nutritional benefits can serve as
a sort of stepping-stone to cost-effective high volume production.
"We've seen in the last 18 months to two years a real
emergence of one particular algae feed ingredient, which I believe will be the
tip of the spear in terms of bringing [algae] to mass markets, which is the
omega-3 fatty acids."
He cautions that commercial production of algae currently is
for high-value specialised feed ingredients rather than crude protein biomass.
However, Dr Carr predicts a trajectory for the sector which
will see companies initially scale-up production in order to manufacture these
expensive ingredients, but then move into the space occupied by higher-volume
commodity feedstuffs once prices for algae production fall.
"We're seeing the move along that trajectory, which is quite
"I think it's only a matter of time before we see broader
adoption as an alternative to other feed commodities."
Having the incentive of high value payouts from specialty
algal ingredients is necessary in order to face the considerable obstacles to
the use of algae in feed.
One such obstacle is the requirement of complex processing
in order to render algae digestible and their nutrients bioavailable.
According to Dr John Forster, "in the raw state, seaweed
nutrients are protected by indigestible cell walls, or are chemically bound in
a way that diminishes their potential nutritional value".
Bleakley and Hayes flagged studies that "appear to suggest
that unprocessed seaweed proteins have reduced digestibility compared to that
of other protein sources", adding that "improved extraction methods of cell
disruption and extraction are therefore required" for commercial production.
Production of algae also presents challenges, whether it's a
question of harvesting wild-grown sources or farming it in controlled
When it comes to harvesting seaweed, Bleakley and Hayes
point out that the regulation of such activities remains in its infancy.
Technical advances are also required. In some geographies,
or for some species, harvesting by hand remains the norm.
When it comes to farming microalgae in enclosed vessels,
several problems arise. Ensuring all the organisms have access to light
requires solutions such as turning or stirring the medium and preventing build-up
on the containers' surfaces.
Meanwhile, farming in open ponds makes keeping out undesired
species difficult, renders temperature control nearly impossible and thus often
operates sub-optimally, and in many cases, consumes precious freshwater
Harvesting the quick-growing crops is a nearly constant
activity, and separating them from the growth medium requires significant inputs
'Main constraint is investment'
These complications have traditionally made algae a solution
that was difficult to ramp up.
However, Vitor Verdelho Viera, president of the European
Algae Biomass Association, disagrees with the assertion that technology is
still the factor limiting algae's growth as a feed ingredient.
"The 'biofuels from algae' phenomena that emerged 10 years
ago pushed the technology and provided a wide range of solutions for the
technology bottlenecks," he said in correspondence with Feedinfo News Service.
"At the moment, the main constraint is the investment in
very large scale operations that can bring the costs down."
He argues that closed systems may be used to produce a
continuous source of a stable inoculum (which can be conceived of as similar to
starter seeds in greenhouses), then several open systems can be used for the
Bacteria are by far the most numerous lifeform on earth,
outweighing both plants and animals.
Of course it is rare that they serve as the biomass for
human foods, even though they are important to transforming many fermented
However, at least one species, Methylococcus capsulatus, is being used as the basis for feedstuff
by at least two companies, Calysta and Unibio.
Methylococcus capsulatus is a methanotroph, meaning it
metabolises methane, a greenhouse gas that is produced by many sources but
notably as a byproduct of the petroleum industry.
Therefore, bacterial protein from methanotrophs address two environmental
problems at once, by consuming inputs that are climate-warming wastes and by
producing valuable feed inputs for the animal production industry.
Beyond being a noble effort at capturing and transforming
GHGs, bacterial protein is also a nutritionally robust source of protein, at
least according to the companies manufacturing it - he feed products of both
Calysta and Unibio advertise crude protein levels of over 70%.
Moreover, the amino acid profile is said to be superior to
that of fishmeal.
According to Unibio, their Uniprotein has been tested as
feed for salmon, calves, pigs, and chickens, while Calysta claims their
Feedkind has been tested in salmon, trout, piglets and even pets who have
proven sensitive to other feed ingredients.
But what of production?
Calysta currently operates a market introduction facility to
produce sample quantities, and will be bringing a large-scale production unit
online in Memphis, Tennessee in 2019.
The facility's initial capacity will be 20,000 tonnes
annually, but the company foresees expanding that to 200,000 tonnes.
This site will feature 20 fermenters "each similar in size
to a football field end zone," as well as "several kilometres of piping",
according to the company.
Meanwhile, Unibio brought online a fermentation facility in
October with a capacity of up to 80 tonnes and plans a second "full size commercial
plant" later this year.
The company has also expressed interest in licensing its
technology in order to make UniProtein production possible in a variety of
locations where the natural gas that the product is built out of is currently
going to waste.
Therefore, in spite of the novelty of the concept, at least
two companies are powering ahead with large-scale production.
Moreover, Calysta's partnership by none other than
agribusiness giant Cargill shows that at least one of the most influential
names in animal nutrition is ready to take a chance on this concept.