The sugar-cane yeast (Saccharomyces cerevisiae) is a totally natural product, NOT "Transgenic", obtained in the process of fermentation of the sugar-cane, and it may have a significant importance on animal food.

It has the property of improving significantly the zootechnic rates of the animals because it is a great source of protein. Besides its high proteinic value, the yeast presents as a characteristic a good aminoacids balancing, in which the levels of lysine and methionine stand out regarding other proteinic sources.

The yeast also stands out for the great quantity of vitamin B complex, mostly Thiamine, Riboflavin, Niacin and Panthotenic Acid. There is also a reasonable quantity of ergo-sterol, which makes it an excellent source of vitamin D.

Yeasts are unicellular microorganisms, which have asexual reproduction by sprouting and which develop in the alcohol fermentation.

They present a well-defined cellular membrane, slightly thick in young cells and rigid in adult cells. It has a variable constitution, with predominance of carbohydrates and less quantity of proteins and fats. Internally delimiting the cytoplasm, there is the cytoplasmic membrane, more obvious in adult cells. The small spherical nucleus (0,5-0,15 µ [m]) is well-defined and of variable location.

The yeasts are the most ancient sources of unicellular proteins. The Saccharomyces cerevisiae has been used on animal nutrition for many decades. In the last decades, its use has been improved in birds and swine nutrition.

The yeasts, alive or not, have in their composition a fraction of carbohydrates (20 % to 40 %), which in the majority part belong to the cellular wall, which is mostly composed of ß-glucanos and mananos (MOS), which have a great impact on the immune system and the capacity to prevent the colonization of pathogenic bacteria in the gastrointestinal system. Other components are the nucleotides, represented by the nucleic acids. The nucleotides can have a positive effect on the gastrointestinal system by increasing the growth and influencing the intestinal flora in a positive way.

• Process of Production
• Applications
• Main advantages for the use of yeast on animal rations

Process of Production:
Firstly the must (cane + molasses) is fermented to transform sugar in ethanol. This material is then centrifuged and separated in wine and yeast cream.
Then, the yeast cream excess from the process of fermentation goes to a big drier (spray dried) in the form of cone with an internal disc spinning in high speed (5000 rpm) with temperature around 100°C. This way, the cream suffers an instant drying, preserving to the utmost the nutritional properties of the product.

Applications:
Of all the microorganisms, the yeasts have the most favourable characteristics to be used on animal food. The yeasts increase the resistance to infections, because of having components that increase the immune response. The yeasts have also been used due to their high levels of nutrients that are easily available and of high nutritional value, being an excellent food component for all the young animals and those of quick growth. Moreover, the yeast has the anti-stress function component, which relieves the natural stress of the operations of wean, vaccination, transport etc., very important for any type of livestock.

In the 70’s and 80’s, several zootechnic studies were carried out with the single objective of making yeast viable as an alternative proteinic source. Because of that, until the beginning of the 90’s, yeasts remained "forgotten", and their use was only made viable on animal food when there was a good price regarding their nutritional composition of proteinic base.

Since 1990, the growing interest of the producers of ration for the breeding of shrimps and for the wean of suckling pigs, both in Europe and Asia, made industries adapt their industrial procedure, trying to process yeasts with high quality, which made the growth of the market possible. During this decade, the approach of the zootechnic studies changed, aiming at getting results in the improvement of the performance, prevention of diseases and reinforcement of the immune system and, as a result of this scientific effort, the world-wide industry started to consider yeasts as a preventive additive, with the ability to improve the performance of the animals exposed to stress conditions.

The main advantages for the use of yeast on animal rations are:
Source of nucleotides (aminoacids): It increases the immune response to diseases, improves the intestinal morphology mainly after wean (it generates a bigger intestinal villus2 maturing rate), improves the energetic metabolism and the nitrogen metabolism, besides being a flavouring agent, improving the palatability. The summary of these features is an important factor in the growth of the animals.

Source of MOS (mananoligosaccharides): It improves the intestinal integrity, strengthens the immune system, making the digestive system healthier, increasing the concentration of immunoglobulins of colostrum and thus increasing the protection from bacteria, viruses and other pathogens in the animals wean.

Source of glutamic acid: it improves the palatability of the ration, stimulating its consumption.

In the physical aspect:
Agglutinant power: it improves the quality of the pelletised ration, reducing the “small grains”.

Natural source of vitamins of the complex B, including Inositol (B7): The complex B has a very important function as an anti-stress agent. The INOSITOL (which acts as an intracellular messenger of growth) is an important natural growth promoter.