The effect of feed residues on the quality of aquatic environment in circulating aquaculture systems of african catfish (Clarias gariepinus (Burchell, 1822))

Purpose. To study the peculiarities of relationships between the aquatic environment and the extruded feed residues in the circulating aquaculture systems intended for growing Clarias gariepinus, and changes in the concentrations of inorganic nitrogen compounds and phosphorus phosphates. Methodology. The object of study is the quality of the aquatic environment when modeling the food load in accordance with feeding standards of different age groups of Cl. gariepinus. Water quality in experimental tanks was determined by analytical methods. Findings. It was found that the intake of extruded feed residues into the aquatic environment leads to a deterioration in its quality due to an increase in the concentration of compounds of inorganic nitrogen and phosphorus of phosphates, which negatively affects the vital activity of Cl. gariepinus. Nitrification processes are activated under conditions of sufficient dissolved oxygen content in the environment. The overload of the aquatic environment with organic matter promotes the bacterial transformation processes of nitrogen and phosphorus compounds, which are characterized by the predominance of the ammonification process and the suppression of oxidative processes. Upon completion of the mineralization of the excess organic matter, the appearance of a sufficient amount of dissolved oxygen activates ammonium oxidation and intensifies nitrification process. The leading factors in the ammonification and nitrification processes in an environment saturated with organic matter include the dissolved oxygen content, which regulates the activity ratio of anaerobic amonifying and aerobic nitrifying microflora. Optimum aeration in Cl. gariepinus cultivation systems is determined not only by the direct physiological needs of fish, but also by the need to maintain a sufficient content of dissolved oxygen to ensure nitrification processes. Originality. The study investigated the effect of the food load on the quality of aquatic environment in the circulating aquaculture systems for Cl. gariepinus rearing. Practical value. The study results can be used to optimize Cl. gariepinus growing methods in circulating aquaculture systems with adjustable parameters at high stocking densities. Key words: African catfish, quality of the aquatic environment, food load, inorganic nitrogen compounds, phosphorus phosphate content, circulating adjustable systems.

THE IMPACT OF PRODUCTION TREATMENTS OF FEED CONCENTRATE PRODUCED FROM WASTE OF CEREAL PRODUCTION ON ITS BIOLOGICAL VALUE AND EFFICIENCY IN THE COMPOSITION OF COMPOUND FEED FOR CARP

The following article presents a new raw component in compound feed for carp – feed concentrate produced from cereal production waste. The feed concentrate is based on several types of cereal fodder meal - wheat, pea, barley, as well as wheat bran and unshelled oat grain. The feed concentrate is balanced according to the needs of carp and can be used as feed for carp instead of wheat grain or as a part of compound feed for carp. Heat-moisture processing of compound feed before extrusion is one of the main stages that further ensure the stability of technological processes and the final quality of the feed concentrate. The amino acid composition was determined at various temperatures of the feed concentrate after heat-moisture treatment of + 40, 60, 70 and 80º С at a constant moisture content of the concentrate of +282° С. Amino acid score has been calculated for feed concentrates that have been exposed to various heat treatments. The amino score was calculated in relation to the carp's need for essential amino acids. It was found that an increase in the temperature of the concentrate during heat-moisture treatment leads to a decrease in the content of essential amino acids. For example, the total content of methionine and cysteine in the composition of the feed concentrate at a temperature of +75° C was 0.46%, with the minimum allowable total content of these amino acids in the composition of feed 0,5%. Heat-moisture treatment at a product temperature above +75° C leads to a decrease in the content of essential amino acids and the biological value of the feed concentrate.The process of extrusion of feed concentrate from waste of cereal production has been studied. The glucose content in the feed concentrate was studied at various extrusion modes. The glucose content indicates the degree of modification of the starch during the extrusion process, and the more glucose the product contains, the better it is absorbed by the carp. When extruded with an increase in temperature, the starch passes into a viscous-flowing (gelatinized) state, forming a so-called melt, the cooling of which also leads to the formation of a three-dimensional gel network. The feed concentrate granule becomes monolithic in structure; it becomes quite hard and can harm the intestines of carp. Therefore, it contains wheat bran in an amount of 1%, as a component that is able to weaken the feed concentrate granule. The degree of starch destruction in the composition of the extruded feed concentrate with the addition of wheat bran reached its maximum and the granule became porous, its hardness decreased. It was detected that when the temperature of the feed concentrate after extrusion rises above +100°C, the biological value of the feed concentrate decreases, and it becomes unbalanced in the content of such essential amino acids as lysine, threonine, methionine and cysteine. Therefore, the optimum product temperature after extrusion is +90-100˚C.The effectiveness of extruded feed concentrate was determined in the composition of granulated feed for two- and threeyear-old carp. The feed ratio of the compound feed containing the feed concentrate was 0.9 units, which is 64% lower than of the control compound feed, which includes a non-extruded grain group that is not balanced in terms of carp needs.

Study of extruded feed from wheat ears during early harvest

The object of the study was an extruded feed made from an undivided grain heap of winter wheat, stripped in the phase of waxy ripeness. The use of this type of inexpensive raw material makes it possible to increase the protein content in feed by 7-8% in comparison with feed based on fully ripe grain. The process of extruding feed based on waxy ripeness wheat ears is satisfactory. It has been established that extruded feed based on a grain heap can be successfully used for feeding farm animals. To use extruded feed from wheat ears harvested in the phase of waxy ripeness, the addition of raw materials of animal origin in an amount of no more than 20% is required for feeding fish, which is less than for feed based on full ripeness wheat grain.

Evaluation of physicochemical characteristics and digestibility of an extrudate with common bean for pigs

Objective: To evaluate the physicochemical properties of an extruded feed using bean (Phaseolus vulgaris L.) as a soymeal substitute and to perform pig growth trials, evaluating nitrogen digestibility. Materials and methods: This research was divided into two stages, the first one consisted on the standardization of the extruded feed, where two formulations of bean flour (Pinto Saltillo variety), cornflour (Cafime variety), and soybean meal were evaluated: 20/67/13% and 30/60/10%, respectively. Samples were processed in a single screw extruder at 120-150°C and moisture content of 18-22%. Evaluated physicochemical properties were: expansion index, bulk density, water absorption index, water solubility index, hardness, water activity and color parameters: L*(clarity), a*(red-green chromaticity) and b* (yellow/blue chromaticity). In the second stage, the in vitro dry matter digestibility and fecal apparent digestibility were evaluated using the optimal treatment obtained from stage 1. Results: Optimal conditions for the 20% of bean flour formulation were: Temperature of 124.4°C and moisture content of 18.59%. Extrusion temperature decreased bulk density, hardness, and water activity, but increased L* and expansion index. Moisture content decreased bulk density, water activity, hardness, and a*. In vitro dry matter digestibility was higher for the extruded bean diet in comparison to the control diet (92.33% vs. 85.33%). Conclusions: Results indicated that bean flour is a viable option for animal consumption in terms of nutritional value and good digestibility.

Efficiency of use of prebiotics based on manane oligosaccharides in carp feeding

Purpose. Analysis of productive and economic indicators in the cultivation of age-1+ carp as a result of the use of prebiotics based on mannan oligosaccharides (MOS) in feeding. Methodology. Four ponds were used, two of which were experimental and two control ponds, which were stocked with age-1 scaly carp with an average weight of 76–77 g at a stocking density of 2200 specimens/ha. Fish of Experiment 1 and Control 1 were fed with extruded feed with a protein content of 23%, fish in Experiment 2 and Control 2 were fed with a grain mixture with a protein content of 19%. 0.05% prebiotic based on MOS "Actigen" was added to the diet of experimental groups of carp throughout the growing season. Optimal conditions for carp farming were ensured including control over oxygen, hydrochemical and hydrobiological regimes in ponds, which were measured according to the generally accepted methods in fish farming. Fishery and economic indicators of growing age-1+ were determined after harvesting fish in autumn. Findings. Major hydrochemical parameters in all ponds were within the normative values. The average seasonal biomass of forage organisms of zooplankton and zoobenthos during the growing season did not differ in the experimental ponds and amounted to 10.33-16.23 g/m3 and 1.23-2.96 g/m3. A positive effect of the use of prebiotics based on MOS in the feeding of age-1+ carp was established. When the prebiotic was given as a part of the extruded feed, the average weight of fish was higher by 11.5%, and fish productivity by 22.7% relative to the control group, while the cost of feed for cultivation was lower by 20%. When it was added to the grain mixture, these values were higher by 12.9%, 16.3% and 16.7%, respectively. The profit, as a result of the use of the prebiotic based on MOS in the composition of the extruded feed increased by 43.3% compared to Control 1, and by 19.1% compared to Control 2 when it was added to the grain mixture. Originality. For the first time, a comparative analysis of the effectiveness of the use of the prebiotic based on MOS in the composition of extruded feed and grain mixtures was performed taking into account productivity and economic indicators. Practical value. The obtained results indicate the feasibility and effectiveness of the use of prebiotics based on MOS in the feeding of age-1+ carp. Introduction of experimental additives to feeds of different composition helps to obtain additional growth and increase the economic component in the cultivation of carp to marketable condition. Key words: carp, prebiotic, feed, productivity, efficiency, profit hydrochemical and hydrobiological indicators.

INFLUENCE OF FEED HEAT TREATMENT ON PRODUCTIVITY OF DAIRY COWS

Experiments on the use of extruded feed in the diets of high-yield cows were conducted. The work was carried out on the farm of LLC Druzhba in the Buinsky district. The object of the study was cash cows. The grain mix of the first experimental group of cows included 15 % – corn, 42 % – peas, 25 % – rye, barley –18 %, the second experimental group 20 % – peas, 30 % – rapeseed, 25 % – corn and 25 % rye. The composition of the extruded feed of the third group was identical as in the second, the difference was only in the fact that rapeseed was previously sprouted for 48-72 hours before extrusion, and then mixed with the rest of the feed mixture. The nutritional content of all three compositions of extruded feed was identical.

USING RAW POTATO PEEL IN THE PRODUCTION OF EXTRUDED FEED ADDITIVE

The paper is concerned with some aspects of processing raw potato peelings. It presents the dynamics of potato production in the world and in Ukraine, and analyses the figures on yields of this crop. Methods of processing potatoes at Ukrainian enterprises have been considered. It has been found that the bulk of the waste (15–60%) is formed during peeling raw potatoes. Methods of utilisation of potato peelings have been analysed. Problems of using fresh potato peel in the diet of farm livestock have been analysed. The technological operations of potato waste processing have been considered, and it has been substantiated how practical the method of extrusion is. The advantages of manufacturing an extruded feed additive with the use of potato peel have been shown. The physical properties, chemical composition, and term of storage of fresh potato peel have been determined. It has been found that fresh potato peel is poorly storable and hardly flowable, so it must be processed within 48 hours. To produce an extruded feed additive including crushed wheat grain and fresh potato peel in the ratio 9:1, a step-by-step scheme has been developed. The physical properties, the content of individual nutrients and minerals, and the shelf life of the extruded additive have been determined. It has been established that manufacturing the feed additive by the method suggested allows increasing the product’s nutritional value, prolonging its shelf life, improving its sanitary quality, technological properties, and conditions of feeding potato peel to livestock. It has been found that when the amount of potato peel introduced is 10% and that of crushed wheat grain is 90%, the optimal moisture content is 16.5%. Besides, this ratio results in the minimum energy consumption and in a coefficient of expansion high enough. During extrusion, the physical properties change: the moisture content, angle of repose, and bulk density decrease, while the flowability increases, which makes the feed additive suitable for use in the feed products technology. Besides, extrusion of the feed additive is accompanied by reduction in crude protein, crude fibre, and crude fat. It has been established that the shelf life of the additive is 4 months

Study of the kinetic regularities of the grain extrusion process in the production of highly digestible feed with protected protein for cattle

The problem of developing of highly digestible compound feeds with protected protein for cattle is due to the specifics of the gastric tract of cows and the peculiarities of protein assimilation. Due to the importance of preliminary moisture-heat treatment of grain for the subsequent course of the extrusion process, it was carried out by steam at a pressure of 0.6 МРа before moistening the feed to a humidity of 17–20% and heating to a temperature of 70–80° C. It is established that heat treatment has a significant effect on the carbohydrate complex of grain: heating it at high temperatures causes the destruction of starch, accompanied by the formation of easily soluble carbohydrates, which has a positive effect on the digestibility of feed. The kinetic regularities of the processes of moisture-heat treatment, grinding and extrusion of grain in the production of highly digestible feed with protected protein for cattle were studied. The degree of dextrinization and the digestibility of starch increased with the heating temperature of corn and its mixtures with wheat up to 100–110° C, when the performance of the extruder was 300–320 kg/h, the digestibility of starch extruded corn and grain mixture is increased to 85 and 68 mg of glucose per 1 g of the product (hereinafter mg/g), respectively. For wheat, this indicator is lower and, accordingly, is 50 mg/g. When heated during the extrusion of corn to a temperature of up to 120–140° C, the digestibility of starch was 100–110 mg/g, and for the grain mixture – 80–83 mg/g. At this temperature, the digestibility of the starch of extruded wheat corresponded to 60–65 mg/g. The optimal moisture content of feed in the process of extrusion for the purpose of forming pellets is 18%. Studies of the extrusion effect on the carbohydrate complex of processed feed have shown that the destruction of starch in the extruded product increases. Thus, the content of soluble carbohydrates increases by 27–32%, and the digestibility of starch increases twice in extruded feed compared to unprocessed.