Microbial protein: The gold standard
The two purposes of the rumen are to break down plant fibre and to produce microbial protein. These are not independent objectives, as producing more microbial protein is accomplished by producing more microbes, which, in turn, results in more fibre breakdown.
Cows are interesting creatures in that the protein they absorb comes from either the cow’s diet or from the bugs that grow and reproduce in its rumen. This protein from the ruminal bugs — known as “microbial protein” — has several nutritional advantages.
Whether a protein comes from an animal, such as in meat or milk, or is microbial or plant-derived, all proteins are composed of amino acids, their so-called “building blocks”. The amino acid building blocks of microbial protein closely match the amino acids found in muscle and milk. This means that microbial protein is ideally suited to fulfil a cow’s amino acid needs.
Furthermore, microbial protein is not affected by rumen degradation. Attempts to reduce the rumen degradation of dietary protein can lead producers and nutritionists to look for expensive “bypass protein”. However, microbial protein, which is produced naturally, achieves the same purpose — and it is made in and by the cow herself.
By increasing microbial protein production, less total dietary protein is required, and opportunities arise for dairy farmers to reduce their nitrogen load on the environment and to increase the efficiency of the nitrogen capture by their animals. Further efficiencies can be gained by controlling the release of non-protein nitrogen in the rumen. Certain technologies — like Optisync™ from Alltech — can be incorporated into rations to improve nitrogen retention by ruminants, as well as their environmental footprint.
In summary, while it may seem counterintuitive, the best source of protein for ruminants is microbial protein, which comes from the bugs that live in their own rumens. Adopting technologies that aid in producing microbial protein is a sound practice.
Note: In Oceania, the Alltech product Optigen™ is distributed as Optisync™. It is the same product only with a different name.