The extrusion process is considered to be the most widespread method of heat treatment of raw material and one of the most modern methods of processing, aiming at the production of the highest quality fodder.
Extrusion is a process of crushing the material in order to create high pressure and heat the material to 130C – 135C at the same time
It should be noted that the extrusion of feeds is also accompanied by the following factors:
Heat treatment: – Quick heating of the material to a temperature of 130-135C results in inactivation of anti-nutritional substances: trypsin inhibitors and urease in feed, which negatively affect feed absorption in animals and may lead to metabolic disorders,
Sterilization: – High temperature contributes to the destruction of bacteria (including salmonella), fungi, molds, viruses and spores, thus prolonging the shelf-life of the forage product for feeding animals.
Expansion: – After leaving the extruding die the extrudate gets into an area with significantly lower pressure and temperature. At this point, the steam rapidly evolving from the substance also breaks the product, and more specifically breaks the fat cells, thus increasing the availability of energy derived from fats.
The availability of amino acids in the diet increases due to the breakdown of the protein structure
Stability: – As a result of inactivation of enzymes: lipases and lipoxidases, which are responsible for the breakdown of fats,
The palatability of the product increases – starch is decomposed into simpler and sweeter components, the unpleasant volatile flavor components are neutralized (e.g. bean flavor of soy), the finished product is further subjected to crumbling and its natural homogeneous structure makes its structure better as compared to those of traditional raw materials.