In the world of pet food, new sources of protein are making their way that do not come directly from meat or fish. Among these are microbial proteins, obtained by growing microorganisms through fermentation processes and also considered interesting due to their possible lower environmental impact.
A new study has now tested these proteins in kibble intended for dogs and cats, discovering that the animals not only accepted them, but in the test carried out showed a certain preference for the formulation that contained them.
What are microbial proteins
The name may seem complicated, but the principle is quite simple. In special systems, inside large containers called bioreactors, microorganisms such as bacteria and yeasts are grown in controlled conditions.
During their growth these microorganisms produce biomass, i.e. cellular material which can be very rich in proteins. It is this biomass, after being collected and subjected to specific treatments, that becomes an ingredient that can be used in food production.
It therefore does not mean that live bacteria are added to the food. The process starts with microorganisms, which are grown and used to obtain a concentrated source of proteins. These proteins are also often referred to by the acronym SCP (Single Cell Protein).
Why are they so interested in the pet food sector? The reason is above all environmental. Dogs and cats consume enormous quantities of food every year and an important part of their diets contains proteins of animal origin.
Producing meat means raising animals, feeding them and using resources such as land and water, as well as generating greenhouse gas emissions. For this reason, alternative protein sources that can at least partially reduce the dependence on animal production have been sought for some time. And microbial proteins actually have an interesting feature: microorganisms can grow very quickly and in relatively small spaces, without the need for large agricultural surfaces. Production also takes place in controlled environments and can be carried out throughout the year.
In some systems, microorganisms can then be grown using by-products or raw materials from other supply chains, transforming nutrients that would have limited value into new protein biomass. It is one of the aspects that makes this technology interesting also from a circular economy perspective.
Are they really more sustainable than meat?
The fact that a protein is produced by microorganisms does not automatically mean that it has a low environmental impact. In fact, fermentation requires energy, water and nutrients to grow microorganisms and keep the systems functioning. The final result therefore depends a lot on how the production process is organised.
Available research indicates that microbial proteins may require less agricultural land and, in some systems, less water than proteins obtained from animals. Furthermore, some processes can use by-products or raw materials from other processes, transforming them into new protein-rich biomass.
The advantage, however, is not the same for all productions. Using energy from renewable sources and recovered raw materials can reduce the environmental footprint, while a very energy-intensive process powered by fossil fuels could limit it. For this reason, to understand how sustainable they really are, we must consider the entire life cycle of the protein, from the raw material used to grow the microorganisms to the energy needed for fermentation, processing and transport.
The interesting prospect, however, is that of being able to replace at least part of the animal proteins used in pet food with proteins produced through fermentation, thus reducing the need to resort to breeding. It is a possibility yet to be evaluated on a large scale, but which could contribute to making the sector less dependent on animal sources.
It is therefore still early to consider microbial proteins as the solution to the environmental problem of pet food. However, they are one of the alternatives that research is studying and their potential will depend above all on how efficiently and with what resources they are produced.
Do dogs and cats prefer them?
The new study, published on, attempted to answer this question Plos Onewhich involved 30 dogs and 30 cats.
Their owners were asked to offer the animals, directly at home, two different formulations of kibble: a control one and one containing 10% microbial proteins. In the latter, the new protein source completely replaced the fish meal and partly the poultry meal present in the traditional formulation.
For four meals spread over two days, dogs and cats had both bowls available at the same time and were left free to choose. In this way the researchers were able to observe the animals’ preference in a familiar environment, without taking them to the laboratory. The result was quite interesting: both dogs and cats showed a preference for kibble containing microbial proteins.
Among the dogs, approximately 72% of the food consumed came from the microbial protein formulation, versus 50% from the control formulation. Cats also showed a preference, albeit more limited: they consumed approximately 51% of the formulation with microbial proteins, compared to 34% of the control one.
The researchers also observed which bowl the animals reached first. Even considering this aspect, both dogs and cats showed a tendency towards the formulation containing the new protein source.
The result is therefore interesting because it indicates that, at least in this test, the introduction of microbial proteins did not make the kibble less palatable. In contrast, the animals showed a preference for the alternative formulation.
But that doesn’t mean they are healthier. The study mainly evaluated the food preference and composition of the two formulations. However, he did not follow the animals for a long enough period to determine whether a diet containing microbial proteins had positive or negative effects on their health.
The two types of kibble were also analyzed from a nutritional point of view and were found to be comparable for various components, including amino acids, minerals and fats.
However, this does not allow us to conclude that microbial proteins are “healthier” than meat or fish. To reach such a conclusion, much longer studies would be needed, capable of also evaluating digestion, metabolism, intestinal microbiota and the animals’ long-term health status.
Then there is another element that is worth knowing. The two authors of the research work for MicroHarvest, the company that produced the microbial proteins used in the study, and the research was funded by the same company.
The preference test was carried out by an external organization and the food analyzes were entrusted to an independent laboratory. However, the possible conflict of interest remains important information for correctly interpreting the results.
It doesn’t mean that the study should be discarded, but that its results should be considered for what they are: a first test on the palatability of an ingredient developed for pet food, not definitive proof that this technology is better from every point of view.
Sources: Plos One
