EFFECT OF EXTRUSION ON PROBIOTIC FEED ADDITIVE

Today, in Ukraine, the issue of producing high-quality and safe livestock products is solved by the introduction of intensive technologies that involve the use of various feed additives, including vitamins, probiotics, prebiotics, macro-and microelements. In recent years, the development of feed additives using live cultures of microorganisms, so-called probiotic products, has attracted much attention of scientists. The strategy in the creation of these products is aimed, first of all, at ensuring the physiological needs of the animal body in biologically active substances. The addition of probiotic supplements to feed increases the bioavailability of nutrients, health, immunity, performance and conservation of animals. Probiotic feed additive EnzActive is a special product on the market of feed additives, the addition of which to feed is aimed at reducing, and in the future, the complete elimination of the use of antibiotics in animal feeding. The article examines the mechanism of action of active fodder yeast on the body of farm animals and proves that the use of active fodder yeast in animal feeding helps reduce the cost of feed due to better assimilation by the animal's body and reduction of morbidity among animals. Methods of introduction of active fodder yeast into the technological process of compound feed production are analyzed. On the basis of theoretical and experimental data, a structural scheme for the extrusion of grain raw materials with active fodder yeast is proposed, which involves preliminary mixing with crushed grain raw materials to obtain a highly homogeneous and stable composition. The physical properties of the feed additive, which includes corn grain and active feed yeast EnzActive, were experimentally determined, which indicate that, compared to the loose, extruded feed additive, it has the following advantages: the mass fraction of moisture decreases by 24.4%, the natural slope angle increases by 11, 6%, the flowability decreases by 48.2%, and the volumetric weight decreases by 24%. When extruding corn grain with active fodder yeast, the degree of starch dextrinization is 59%, and the extrudate expansion index is 2.3. Microbiological indicators were determined, which indicate that the number of yeast cells in extruded grain with active feed yeast EnzActive was only 6% compared to the number of yeast cells in untreated corn grain with active feed yeast.


Introduction
The use of modern technologies for feeding agricultural animals and poultry is impossible without highquality feed. The use of compound feed in animal husbandry makes it possible to: -to increase the average daily increase in live weight of animals during fattening by 1.5-2.0 times; -reduce feed costs for the production of livestock products by 20-30%; -reduce the duration of poultry and animal fattening by 30-35%; -to mechanize the process of feeding agricultural animals and poultry.
Thanks to the widespread use of compound feed, it became possible to create large livestock complexes and poultry farms. It was the use of compound feed that made it possible to transfer livestock and poultry farming to an industrial basis, which significantly increased labor productivity in these branches of the agro-industrial complex. Long-term stay of animals and poultry in closed rooms in conditions of limited movement in stable, cage keeping, limiting contacts with the external environment can lead to weakening of immunity, metabolic disorders, reduction of productive and re-productive qualities, emergence of diseases. It should be noted that keeping animals in closed rooms requires an increased content of vitamins, macro-and microelements and other biologically active substances in compound feed.
Recently, numerous feed additives have been used in the diet of farm animals, the use of which does not always have a positive effect on the quality of products. Among feed additives of natural origin, probiotic supplements have become widespread. [1,2] Enzym Company, the largest producer of yeast in Ukraine, presents its new animal feed product on the domestic market -EnzActive active feed yeast is a probiotic live active feed additive that improves the efficiency of fattening and the nutritional value of livestock products. The live active probiotic feed supplement is ISO 22000, FSSC 22000, GMP+, HACCP, Kosher and Halal certified.

The purpose of the study
The purpose of the work is to study the effect of heat treatment on the quality of feed products using biologically active substances, namely active feed yeast EnzActive.
To achieve the set goal, the following research tasks must be solved: -to analyze the state and prospects of using active fodder yeast in feeding agricultural animals; -consider the mechanism of action of active fodder yeast on the animal body; -to analyze the ways of introducing active fodder yeast into the technological process of compound feed production; study the influence of the extrusion process on the nutrients of grain raw materials and analyze the efficiency of using extruded grain in feed; -to determine the physical properties of extruded grain raw materials with active fodder yeast; -to investigate the effect of heat treatment on active fodder yeast.

Results and its discussion
Active fodder yeast is a widely distributed probiotic today, the use of which has many advantages of an economic, zootechnical and veterinary nature. Active fodder yeast can be used in farms, agrarian firms, enterprises that produce fodder for farm animals or have feed mills.
The unique production technology and mechanism of action of active fodder yeast ( Fig. 1) when feeding farm animals contribute to: -reduction of the total cost of feed due to its better assimilation by the animal's body; -ensure stability of the body's internal environment; -prevent the development of many diseases and pathological conditions. [2][3][4] There are various methods of introducing biologically active substances into the compound feed. Practice shows that the introduction of individual vitamins, microelements and other components directly into the compound feed is a less effective method than the use of these substances in the form of vitamin, mineral mixtures or premixes (preliminary mixtures) [5,6].
Many compound feed factories consider the possibility of independent enrichment of compound feed products with both individual biologically active substances and preliminary mixtures. The variety of recipes of enrichment mixtures and their concentrations on the feed raw materials markets of many countries sometimes puts specialists in a difficult position when solving the "price -quality" problem. The choice of the construction option for the scheme of the technological process of compound feed enrichment depends on the concentration of drugs or preliminary mixtures. [6] The Enzym Company specialists recommend using EnzActive in the feeding of farm animals -adding it to a balanced basic diet throughout the growing period in the amount of: 100-150g/t of feed for broilers, 50-100g/t of feed for laying hens, 200-500 g/t feed for pigs, 500 g/t feed for cattle or 4-10g/cow/day in two doses (morning and evening). It should be noted that research on the use of EnzActive yeast in feeding farm animals was carried out by adding it to feed in loose form or individually to each animal separately. [3] The introduction of the EnzActive feed additive in a very small amount into the composition of compound feed, technological methods should be used that ensure high accuracy of dosage and the uniformity of the distribution of biologically active substances in the composition of compound feed. The uniformity of the distribution of EnzActive feed additive depends on the type of mixer, duration of mixing, physical and technological properties of raw materials (flowability, degree of grinding, ability to mix, etc.). [6] One of the ways to solve the problem of introduction of feed additive EnzActive into the compound feed is a slight modernization of the scheme of the technological process of the production of compound feed products, namely the installation of an additional mixer of small capacity for the preparation of a preliminary mixture with one of the components of the compound feed. Pre-mixing is a guarantee of the formation of not only a highly homogeneous, but also a stable composition.

Fig. 1 -The mechanism of action of EnzActive yeast in feeding farm animals [2-4]
EnzActive yeast in farm animal feed

Cattle breeding
Mechanism of action: -by absorbing residual oxygen, they improve the general condition of scar microflora; -stimulate cellulolytic activity; -provide a stable pH level of the rumen; -improve the structure of epithelial villi; -protect the body from bacteria and their toxins; -contribute to better digestibility of nutritious forage.

Mechanism of action:
-restoration and normalization of intestinal microbiocenosis; -promotion of better digestibility of feed nutrients; -protection of the body from bacteria and their toxins; -optimal development of the immune system.

Poultry breeding
Mechanism of action: -improve the structure of the villi of the intestinal epithelium; -prevent damage by pathogenic microorganisms; -strengthen the immunity of pigs; -neutralize toxins; -bind and remove mycotoxins; -suppress the reproduction of pathogenic microorganisms; -normalize the processes of enzyme synthesis in the digestive tract of pigs.

Swine breeding
The manufactured compound feed product must meet the physiological characteristics and needs of the farm animals for which it is intended as fully as possible. In this regard, compound feed products must have appropriate organoleptic properties, must ensure high productivity of animals, be safe for them and retain their properties during the guaranteed shelf life. [5,6] In the production of compound feed for farm animals, the basis of the diet is made up of grain components. The grain of cereal crops, along with other types of nutrients, contains a significant amount of starch, the assimilation of which occurs slowly when feeding poultry, and at the same time, only certain forms are used productively in small quantities. According to a number of studies, the digestibility of the nutritional potential of starch in its natural form does not exceed 20...25%, depending on the type of crops. Therefore, the task of new grain processing technologies is to implement such methods of processing raw materials that would allow converting starch into a form convenient for assimilation by the animal body. This is possible when the granular structure of starch is destroyed at the cellular level, which contributes to its dextrinization and conversion into lowmolecular carbohydrates. [7] Heat treatment contributes to the breakdown of complex nutrients contained in feed into the simplest ones, thereby reducing the energy consumption for their digestion in the animal's body [5,8].
Currently, there are quite a lot of technologies that allow heat treatment of fodder, but for most of them it is necessary to use external heat sources, which requires additional capital investments. Extrusion is one of the most effective and widespread methods of grain processing in the world compound feed industry, which is used both in combination with granulation and independently. When processing grain fodder in this way, two continuous processes occur: 1) thermomechanical deformation and biochemical transformations; 2) the process of adiabatic expansion ("explosion") of the product, which acquires a porous structure. [8,9] The raw material to be extruded is brought to a moisture content of 16...18%, crushed and fed into the extruder, where under the action of high pressure (2.8...3.9 MPa) and friction, the grain mass is heated to a temperature of 120...150 °C and acquires a thermoplastic properties [9]. Then, as a result of its rapid movement from the high-pressure zone to the atmospheric pressure zone, the process of adiabatic expansion occurs (the socalled "explosion"), as a result of which the homogeneous mass forms a product of a microporous structure, the most favorable to the effect of gastric juice, and therefore ensures a more complete assimilation of nutrients by the body animals (25...30% more than usual). Extrusion takes less than 30 seconds. During this time, the raw material has time to go through the stages of grinding, mixing, heat treatment, disinfection, dehydration, stabilization and homogenization and volume increase. [9][10][11]. In the process of extrusion (Fig. 2), protein denaturation, inactivation of anti-nutrients (protease inhibitors, phytohemagglutenins, etc.) occurs.), starch dextrinization, destruction of cellulose-lignin formations, fiber partially disintegrates, the level of urease activity in soybean grains decreases (urease activity 0.1...0.2 units of pH). At the same time, the amount of starch decreases by 12...15%, and dextrins increases more than 5 times, the amount of oligo-and monosaccharides increases by 11...12%. The sanitary quality of grain and compound feed improves, as the final products contain virtually no microorganisms. [7,10].
Taking into account the useful properties of extruded products, we developed a method of enriching grain crops with biologically active substances (Fig. 3), namely with active feed yeast EnzActive. As a result, experimental samples of feed additives for farm animals were produced, in which physical properties were determined before and after extrusion. [5,12] Samples of feed additives were studied according to the indicators that most characterize the technological properties of the finished products, namely the angle of natural slope, flowability, volumetric weight, and the efficiency of the extrusion process was determined by the extrudate expansion index, the degree of starch dextrinization, and the mass fraction of moisture. Table 1 shows the results of the study of changes in the physical properties of the feed additive, which includes corn grain with active feed yeast EnzActive, during the extrusion process.  Analysis of the data given in the table. 1, shows that in the process of extruding the feed additive, the mass fraction of moisture decreases by 24.4%, the angle of natural slope increases by 11.6%, the flowability de-creases by 48.2%, and the volumetric mass decreases by 24%. When extruding corn grain with active fodder yeast, the degree of starch dextrinization is 59%, and the extrudate expansion index is 2.3. To determine the total number of yeast cells, samples of raw corn grain with active feed yeast En-zActive and samples of extruded corn grain with active feed yeast EnzActive were taken. The number of yeast cells in the samples is shown in Fig. 4, which were determined by the method of direct counting of cells of microorganisms using the Goryaev counting chamber. [13] The number of yeast cells in extruded grain with EnzActive active feed yeast was only 6% compared to the number of yeast cells in untreated corn grain with active feed yeast. Therefore, the temperature during extrusion significantly affects the activity of active feed yeast EnzActive, despite the fact that the extrusion process lasts up to 30 seconds. The surface coat of the yeast pellet, consisting of inactivated yeast cells, does not protect the active yeast cells contained within the active yeast pellet from the effects of temperature.

Conclusions
Live active probiotic feed additive EnzActive is an innovative product whose addition to feed is aimed at reducing, and in the future, completely eliminating the use of antibiotics in animal feeding. EnzActive helps to increase the efficiency of fattening and the nutritional value of livestock products.
One of the ways to introduce a small amount of feed additive EnzActive into compound feed is to prepare a preliminary mixture with crushed grain raw materials to 1,3х10 6 obtain a highly homogeneous mixture, so that in each portion of compound feed the ratio of components according to the recipe is ensured during the guaranteed period of storage and transportation. The use of heat treatment will increase the feed value of grain raw materials and will allow to maintain a stable composition of feed supplement with active feed yeast EnzActive.
The physical properties of the feed additive, which includes corn grain and EnzActive active feed yeast, show that, compared to loose, extruded feed additive, it has the following advantages: the mass fraction of moisture decreases by 24.4%, the angle of natural slope increases by 11.6%, the flowability decreases by 48.2%, and the volumetric weight decreases by 24%. When extruding corn grain with active fodder yeast, the degree of starch dextrinization is 59%, and the extrudate expansion index is 2.3.
Microbiological indicators show that the number of yeast cells in extruded grain with active feed yeast EnzActive is only 6% compared to the number of yeast cells in untreated corn grain with active feed yeast.