Effect of a leveling device on mixing uniformity and energy efficiency of a small-scale screw feed mixer

Efeito de um dispositivo de nivelamento na uniformidade de mistura e na eficiência energética de um misturador helicoidal de pequena escala

Abstract

Small farms require compact feed mixers that provide uniform total mixed ration under limited drive power. Conventional screw mixers rely on repeated lifting and gravitational collapse of the feed mass, which increases friction losses, promotes stagnant zones, and raises specific energy consumption in small hopper volumes. This study investigated the effect of a leveling device installed in a small-scale horizontal screw feed mixer-dispenser on feed mass redistribution, mixing uniformity, and energy efficiency under practical operating conditions typical of small farms. The proposed device intensifies redistribution of the surface fibrous feed layer through controlled shear deformation and horizontal redistribution without lifting the entire feed volume, thereby reducing internal friction losses and stabilizing component exchange between hopper regions. The study combined theoretical force-based analysis of feed layer deformation with comparative experimental investigations using roughage-concentrate feed mixtures under operating conditions corresponding to hopper volumes of 3.0-4.0 m³ and batch masses of 800-1000 kg. The obtained results demonstrate that controlled redistribution of the surface feed layer improves mixing stability and energy efficiency while preserving the physical structure of fibrous feed components. The proposed concept can improve the technological and energy efficiency of small-scale feed preparation systems without increasing installed drive power.

Keywords:
screw feed mixer; leveling device; mixing uniformity; energy consumption; small farms; Total Mixed Ration (TMR)

Resumo

Pequenas propriedades agrícolas necessitam de misturadores compactos de ração que garantam a uniformidade da ração total misturada sob condições de potência limitada. Misturadores helicoidais convencionais baseiam-se na elevação repetida e no colapso gravitacional da massa de ração, o que aumenta as perdas por atrito, favorece a formação de zonas estagnadas e eleva o consumo específico de energia em volumes reduzidos de mistura. Este estudo investigou o efeito de um dispositivo nivelador instalado em um misturador-distribuidor helicoidal horizontal de ração de pequena escala sobre a redistribuição da massa de ração, a uniformidade da mistura e a eficiência energética sob condições operacionais típicas de pequenas propriedades agrícolas. O dispositivo proposto intensifica a redistribuição da camada superficial fibrosa da ração por meio de deformação por cisalhamento controlada e redistribuição horizontal, sem elevar todo o volume da massa, reduzindo assim as perdas por atrito interno e estabilizando a troca de componentes entre as regiões dos misturador. O estudo combinou análise teórica baseada em forças de deformação da camada de ração com investigações experimentais comparativas utilizando misturas de volumosos e concentrados, sob condições operacionais correspondentes a volumes de tremonha de 3,0-4,0 m³ e massas de lote de 800-1.000 kg. Os resultados obtidos demonstraram que a redistribuição controlada da camada superficial da ração melhora a estabilidade da mistura e a eficiência energética, preservando a estrutura física dos componentes fibrosos da ração. O conceito proposto pode melhorar a eficiência tecnológica e energética de sistemas de preparo de ração em pequena escala, sem aumentar a potência instalada.

Palavras-chave:
misturador helicoidal; dispositivo nivelador; uniformidade de mistura; consumo de energia; pequenas propriedades agrícolas; Ração Total Misturada (TMR)

1. Introduction

In livestock production, feed preparation and distribution are critical technological operations that directly influence animal productivity, feed intake stability, and production costs. Feed preparation accounts for a substantial share of operating expenses, while feed mixture quality determines nutrient utilization and feeding efficiency (Golikov et al., 2014)

This issue is particularly relevant for small farms operating under limited energy and technical resources. Such farms require compact, energy-efficient, and adaptable machinery capable of ensuring stable feed preparation under reduced hopper volumes and limited available drive power (Semenikhin et al., 2017; Povalikhin and Karpov, 2015). Existing feed mixer-dispensers are predominantly designed for medium and large livestock enterprises and are commonly characterized by relatively high installed power and hopper volumes exceeding 6.0 m³ (Braginets et al., 2016). Under small-scale operating conditions, such machines often demonstrate reduced mixing efficiency and increased specific energy consumption due to the mismatch between machine design and actual batch size and hopper filling degree (Kurkov et al., 2019).

Conventional feed mixer-dispensers typically employ horizontal or vertical screw working bodies, where mixing is based on repeated lifting of the feed mass followed by gravitational collapse (Alexandrov, 2020; Abilzhanuly et al., 2024). Although this mechanism is widely used because of its structural simplicity, it remains energy-intensive regardless of machine configuration. As hopper volume and feed mass decrease, the efficiency of this mixing principle decreases significantly because a considerable part of drive energy is consumed for lifting the feed mass and overcoming friction forces between the feed mixture, working bodies, and hopper surfaces (Tsoy et al., 2018; Frolov and Sysoev, 2011).

Experimental and theoretical studies indicate that increasing screw rotational speed or extending mixing duration does not necessarily provide proportional improvement in feed mixture uniformity and often leads to additional compaction of the feed layer and increased energy consumption (Zavrazhnov and Astapov, 2007; Bridgeman, 2012). Current engineering solutions mainly focus on intensifying feed lifting processes through modification of screw geometry, rotational speed, or additional mixing elements (Mertens, 1994; Heinrichs and Kononoff, 2002). However, the problem of controlled feed layer redistribution within the hopper remains insufficiently investigated, particularly under conditions of small feed volumes and limited installed power.

Recent studies on total mixed ration (TMR) preparation systems demonstrate that the efficiency of feed mixing processes depends not only on screw geometry and rotational speed, but also on rheological behavior, compressibility, internal friction, and shear resistance of fibrous biomass materials (Shi et al., 2023; Wang et al., 2022). Moist fibrous feed mixtures exhibit complex viscoelastic and anisotropic behavior, which significantly affects particle redistribution, formation of stagnant zones, and energy dissipation during mixing processes (Navarro et al., 2022). Under operating conditions typical of small farms, these effects become more pronounced because reduced hopper volume and limited feed mass decrease circulation stability and intensify local compaction of the feed layer (Zhou et al., 2023).

Several contemporary investigations have shown that conventional approaches based on increasing rotational intensity often lead to excessive mechanical loading, increased specific energy consumption, and degradation of fibrous feed structure without proportional improvement in mixture homogeneity (Kim et al., 2021; Ferreira et al., 2024). Excessive mechanical impact may also negatively affect particle size distribution of roughage, which plays an important role in feed intake behavior and physiological feeding efficiency (Leonardi and Armentano, 2003).

The physical behavior of moist fibrous feed mixtures differs substantially from classical granular media because internal structure, local compaction, and fiber interaction strongly affect material movement during mixing (Wang et al., 2022; Navarro et al., 2022; Zhou et al., 2023; Zhou et al., 2023; Kim et al., 2021; García et al., 2003). Studies on feed structure and feeding efficiency indicate that excessive mechanical impact may destroy the optimal particle size distribution of roughage required for maintaining feed quality and physiological feeding efficiency (Ahmed et al., 2023; Li et al., 2024).

Modern feeding technologies increasingly incorporate automated and mobile feed preparation systems; however, their effectiveness remains strongly dependent on feed mixture uniformity and stability of component distribution (Da Borso et al., 2017; de Koning, 2010). Therefore, improvement of mixing quality under low-power conditions remains an important engineering task.

Despite significant progress in the development of feed preparation technologies, limited attention has been devoted to controlled redistribution of the surface feed layer as an independent mechanism for improving mixture homogeneity under conditions of limited installed power and reduced hopper volumes. Most existing studies focus primarily on increasing screw rotational intensity or modifying screw geometry, while the influence of controlled shear redistribution on feed flow stability and energy efficiency remains insufficiently investigated.

Unlike conventional approaches aimed at increasing mechanical intensity, the proposed leveling device modifies the stress–strain state of the surface feed layer by introducing controlled shear deformation without lifting the entire feed volume. This creates conditions for more stable feed mass redistribution and may reduce specific energy consumption while improving feed mixture uniformity (Halachmi, 2009; Chen et al., 2023).

Therefore, the objective of this study is to investigate the effect of a leveling device installed in a small-scale screw feed mixer on feed mass redistribution, feed mixture uniformity, and energy consumption under operating conditions typical of small farms.

2. Materials and Methods

2.1. Object and scope of the study

The object of the study was the feed mass mixing process in a small-scale screw-type feed mixer-dispenser intended for small farms. The investigated machine operated with hopper volumes of 3.0–4.0 m³ and feed mixture masses ranging from 800 to 1000 kg, corresponding to practical operating conditions of small-scale livestock farms.

The study focused on feed mass redistribution inside the hopper, the influence of the leveling device on feed mixture uniformity, and specific energy consumption during the mixing process. Particular attention was given to feed layer formation, feed mass movement trajectories, and conditions required for stable component redistribution.

Experimental investigations were conducted using roughage-concentrate feed mixtures with moisture content ranging from 42% to 55% and average bulk density of 280–360 kg·m⁻³. The roughage fraction consisted primarily of chopped hay and silage components with average particle length ranging from 20 to 50 mm. The operating rotational speed of the screw working bodies varied within the range typical for small-scale feed mixers used in livestock farms.

All experimental investigations were carried out under identical environmental conditions at ambient temperatures of 18-22 °C. Each operating mode was repeated three times to ensure repeatability and reliability of the obtained results.

2.2. Design and technological scheme of the feed mixer-dispenser

The experimental prototype was based on a small-scale feed mixer-dispenser equipped with horizontal screw working bodies. In the base configuration, feed mass movement inside the hopper occurred through longitudinal transport, vertical lifting by the screw, and subsequent gravitational collapse.

A leveling device was installed in the hopper to interact with the surface layer of the feed mass. Its functional purpose was to redistribute the feed layer across the hopper cross-section, eliminate local accumulation zones, and stabilize component exchange without lifting the entire feed volume.

The principal design concept consisted in introducing feed mass leveling as an independent stage of the mixing process, allowing modification of feed layer deformation without increasing screw rotational intensity or installed drive power. The technological interaction between the feed surface layer and the leveling device is illustrated in Figure 1.

Figure 1
Technological scheme of feed mass interaction with the leveling device inside the hopper of the small-scale screw mixer-dispenser.

In contrast to conventional screw mixing systems, where redistribution occurs mainly through cyclic lifting and collapse of the entire feed mass, the proposed leveling device acts primarily on the upper fibrous layer of the material, creating controlled shear deformation and horizontal redistribution of the feed flow. This approach reduces local compaction intensity and improves circulation stability inside the hopper.

2.3. Theoretical research methodology

The theoretical analysis considered the feed mixture as a quasi-continuous deformable medium with anisotropic properties caused by fibrous structure and variable compaction during mixing (Navarro et al., 2022; Kim et al., 2021).

Unlike classical granular materials, moist fibrous feed mixtures exhibit pronounced viscoelastic and rheological behavior characterized by internal cohesion, compressibility, and increased resistance to shear deformation. These properties significantly affect redistribution of the feed layer, formation of stagnant zones, and energy dissipation during operation of screw-type mixers. Therefore, the feed mass was analyzed as a heterogeneous deformable medium with variable local density and anisotropic resistance to particle displacement.

The following assumptions were adopted:

• the feed mass exhibits anisotropic behavior due to fiber orientation;

• bulk density varies depending on local compaction inside the hopper;

• friction coefficients between feed, working bodies, and hopper walls remain constant within the investigated operating range;

• vibration and aerodynamic effects were neglected.

The analysis considered the forces acting on an elementary volume of feed during interaction with the screw and leveling device in order to determine the main energy expenditures associated with lifting, shearing, cutting, and redistribution of the feed layer.

The mass of feed removed by the leveling device during interaction with the surface layer was determined as (Equation 1):

$m_c=B{h}_c{L}_{AB}\rho$ (1)

where m_c is the mass of feed removed by the leveling device (kg), B is hopper width (m), h_c is thickness of the removed feed layer (m), L_AB is contact arc length between the leveling device and the feed surface (m), and ρ is average bulk density of the feed mixture (kg·m⁻³).

The linear velocity of the leveling device fingers was determined by (Equation 2):

$v=2\pi Rn$ (2)

where v is linear velocity of the leveling device fingers (m·s⁻¹), R is the rotation radius (m), and n is rotational speed (s⁻¹).

Power required for feed layer leveling was estimated as Equation 3:

$P=Fv$ (3)

where P is power required for feed layer leveling (W), F is total resistance force caused by friction and internal cohesion of the feed mass (N), and v is linear velocity of the leveling device fingers (m·s⁻¹).

The theoretical approach assumed that reduction of vertical feed displacement and transition toward controlled shear redistribution decrease internal friction losses and reduce the energy required for stable circulation of the feed mass inside the hopper. Particular attention was given to interaction between the leveling device and the upper compacted fibrous layer, where the highest local resistance to particle movement is typically observed.

The obtained theoretical relationships were used to compare the energy characteristics of feed leveling with those of the conventional lifting-and-collapsing mixing mechanism.

2.4. Experimental research methodology

Experimental investigations were carried out using a prototype small-scale feed mixer-dispenser equipped with the leveling device. Feed mixtures consisted of roughage and concentrate components prepared according to zootechnical recommendations for small livestock farms (Leonardi and Armentano, 2003). The feed composition included chopped hay, silage, and concentrated feed components with moisture content ranging from 42% to 55%.

The experimental investigations were conducted under operating modes corresponding to practical farm conditions, including variation of mixing duration, hopper filling level, and rotational speed of the screw working bodies. Hopper filling coefficients ranged from 0.65 to 0.85 of the total hopper volume. The rotational speed of the screw working bodies was maintained within the operating range typical for small-scale feed mixers used in livestock production systems.

Each operating mode was repeated three times to ensure reproducibility and reliability of the obtained experimental results. Two machine configurations were compared:

• base configuration without leveling device;

• modified configuration with leveling device.

The comparison was performed under identical feed composition and operating conditions to isolate the influence of the leveling device on feed mass redistribution, mixture uniformity, and specific energy consumption.

Experimental observations included evaluation of feed mass movement trajectories, formation of stagnant zones, redistribution stability of fibrous components, and duration required to achieve stable mixture homogeneity. Particular attention was given to circulation stability of the upper feed layer and reduction of local compaction zones during operation of the leveling device.

2.5. Assessment of mixing quality

Mixing quality was evaluated based on feed mixture uniformity determined by tracer component distribution in samples collected from different hopper zones (Ferreira et al., 2024).

As a tracer component, concentrated feed particles with visually distinguishable structure and stable distribution characteristics were used. Samples were collected from multiple zones of the hopper and along the feeding front immediately after completion of the mixing cycle in order to evaluate spatial uniformity of component distribution.

Uniformity was expressed using the coefficient of variation of tracer concentration (Equation 4):

$$CV=\frac{\sigma }{\overline{x}}100$$ (4)

where CV is the coefficient of variation (%), σ is the standard deviation of tracer concentration, and x̄ is the mean tracer concentration in the collected samples.

For each experimental mode, at least five samples were collected from different regions of the feed mass. The obtained values were averaged over three repeated experimental trials.

Lower values of the coefficient of variation corresponded to higher feed mixture uniformity and more stable redistribution of feed components within the hopper volume.

The obtained values were compared between the base and modified configurations.

2.6. Energy consumption assessment

Energy performance was evaluated by specific energy consumption, defined as the ratio of consumed drive power to feed mass prepared during one mixing cycle.

Power consumption measurements were carried out under steady operating conditions, including both startup and stable mixing periods, to reflect actual operating conditions of small-scale feed preparation.

Electrical power consumption of the mixer drive was measured using a digital power meter with measurement accuracy of ±1.5%. Measurements were recorded continuously during the entire mixing cycle, including startup and stable operating stages.

Specific energy consumption was determined as the ratio of total electrical energy consumed during one mixing cycle to the prepared feed mass expressed in kWh/t.

Comparative assessment of energy consumption between the two machine configurations was performed under identical operating conditions and equal feed batch mass in order to ensure objective comparison of energy efficiency indicators.

2.7. Methods of data processing and analysis

Experimental data were processed using methods of mathematical statistics. Mean values and variation ranges were determined for each operating mode.

Comparative analysis between the two design configurations was performed based on feed mixture uniformity and specific energy consumption. Repeatability of results was assessed using repeated trials, and averaged values were used for interpretation of technological efficiency.

Statistical analysis of the obtained experimental data included determination of mean values, standard deviations, and confidence intervals for the investigated parameters. Statistical significance of differences between the base and modified configurations was evaluated using Student’s t-test at a significance level of p < 0.05.

Data processing and graphical interpretation of the obtained results were performed using standard statistical analysis procedures to evaluate reproducibility and reliability of the experimental observations.

3. Results

3.1. Mixing process characteristics in the base configuration

Analysis of the experimental results showed that, in the base configuration of the small-scale feed mixer-dispenser without a leveling device, the mixing process is characterized by pronounced non-uniform involvement of the feed mass in the working process. Under typical operating conditions, stable zones of intensive feed mass lifting are formed near the screw working bodies, while zones of reduced mobility develop along the side walls and in the corner regions of the hopper.

These low-mobility zones persist throughout the entire mixing process and exhibit weak dependence on increased operating time of the mixer-dispenser. Even with prolonged mixing duration, complete involvement of the entire feed mass volume in component redistribution is not achieved. This indicates that the traditional lifting-and-collapsing mixing mechanism has limited effectiveness under conditions of small hopper volumes and relatively low feed mixture mass (Frolov and Sysoev, 2011; Mertens, 1994; Heinrichs and Kononoff, 2002).

Further increases in screw rotational speed intensify feed mass lifting and collapse processes but do not provide proportional improvement in feed mixture uniformity. At the same time, specific energy consumption increases due to higher friction forces between the feed mass, the working bodies, and the internal hopper surfaces.

Experimental observations also revealed formation of local compaction zones in the upper fibrous layer of the feed mass, particularly near the side walls and in the corner regions of the hopper. These compacted regions demonstrated reduced circulation intensity and limited participation in component redistribution, which negatively affected overall mixture homogeneity and increased local resistance to feed movement.

3.2. Effect of the leveling device on feed mass movement kinematics

Installation of the leveling device leads to a qualitative change in the kinematic pattern of feed mass movement within the hopper. Experimental observations demonstrated that the leveling device disrupts stable zones of local feed accumulation and promotes more uniform feed mass distribution across the hopper cross-section.

During operation, the leveling device interacts primarily with the surface layer of the feed mass, ensuring its redistribution and preventing formation of localized compaction zones. As a result, feed mass involvement in the mixing process occurs not through lifting the entire mixture volume, but through shear and cutting deformations of the feed layer.

Feed transport follows more stable closed trajectories, which facilitates uniform exchange of components between hopper zones and fundamentally distinguishes the proposed mechanism from the conventional lifting-and-collapsing process (Zavrazhnov and Astapov, 2007; Zhou et al., 2023).

Visual observations during experimental operation demonstrated that the leveling device improves circulation stability of fibrous feed components and reduces formation of stagnant zones along the hopper walls. More uniform redistribution of the upper feed layer contributed to stabilization of internal feed flow trajectories and reduction of local feed accumulation.

The difference in feed mass movement trajectories between the two operating modes is illustrated in Figure 2.

Figure 2
Comparison of feed mass movement patterns in the mixer-dispenser: (a) conventional lifting-and-collapsing mechanism; (b) mixing with the leveling device.

3.3. Effect of the leveling device on feed mixture uniformity

Experimental results demonstrated that application of the leveling device significantly improves feed mixture uniformity. In the base configuration, achieving uniformity levels corresponding to zootechnical requirements required prolonged mixing time and was accompanied by increased energy consumption.

When the leveling device was applied, the required feed mixture uniformity was achieved within a shorter time interval due to more uniform involvement of the feed mass in component redistribution and elimination of stagnant zones.

The obtained comparative indicators are presented in Table 1.

Table 1
Comparative performance of the feed mixer-dispenser configurations.

Parameter	Base configuration	With leveling device
Feed mixture uniformity (%)	83.2 ± 1.7	90.6 ± 1.4
Coefficient of variation (%)	16.8 ± 1.3	9.4 ± 0.9
Specific energy consumption (kWh/t)	5.3 ± 0.3	4.2 ± 0.2
Mixing time (min)	12 ± 0.5	8 ± 0.4

Statistical analysis demonstrated that differences between the investigated configurations were statistically significant at p < 0.05 for feed mixture uniformity, coefficient of variation, and specific energy consumption.

Improvement in feed mixture uniformity was achieved without increasing the intensity of mechanical impact on the feed mass. This is important for preserving the physical structure of roughage and maintaining particle size distribution required for feeding efficiency (Kim et al., 2021; Ferreira et al., 2024; Leonardi and Armentano, 2003).

Additional analysis indicates that the improvement in feed mixture uniformity is associated with transition from periodic compaction to predominantly shear deformation of the surface feed layer. Under such conditions, relative particle movement occurs under lower contact forces, which reduces formation of stable fibrous agglomerates and improves reproducibility of the mixing process.

Reduction of the coefficient of variation from 16.8% to 9.4% confirms improved stability of component redistribution within the hopper and indicates more uniform circulation of fibrous and concentrated feed components during the mixing cycle.

3.4. Energy performance of the mixing process

Comparative analysis showed that implementation of the leveling device reduces specific energy consumption of the mixing process. In the base configuration, a significant portion of drive energy is expended on repeated lifting of the feed mass and overcoming friction forces generated during feed collapse.

When the leveling device is used, feed redistribution occurs predominantly in the horizontal plane through shear deformation of the surface layer, which requires lower resistance forces than full-volume lifting. As a result, peak power demand decreases and loading of the working bodies becomes more uniform.

The reduction in specific energy consumption is associated not only with lower feed lifting energy but also with reduced internal and external friction losses caused by lower feed compaction intensity (Mertens, 1994; Heinrichs and Kononoff, 2002).

Experimental measurements showed that application of the leveling device reduced specific energy consumption by approximately 20.8% compared with the base configuration. This reduction is associated with stabilization of feed circulation trajectories and decreased resistance to movement of the upper fibrous layer inside the hopper.

More uniform loading of the screw working bodies during operation also contributed to reduction of short-term peak loads on the drive system, which may improve operational stability and durability of small-scale feed preparation equipment.

4. Discussion

4.1. Comparison with conventional approaches and literature data

Comparison with published research confirms that conventional mixing intensification methods based on increasing screw rotational speed or mixing duration have limited effectiveness when handling moist and fibrous feeds (Povalikhin and Karpov, 2015; Abilzhanuly et al., 2024; Tsoy et al., 2018; Frolov and Sysoev, 2011; Zavrazhnov and Astapov, 2007).

Several contemporary investigations indicate that classical particulate mixing models are insufficient for describing redistribution processes in heterogeneous fibrous feed mixtures, where rheological behavior, compressibility, internal friction, and anisotropic particle interaction become dominant factors governing material flow inside the hopper (Navarro et al., 2022; Zhou et al., 2023; Kim et al., 2021). Under such conditions, formation of stagnant zones and unstable circulation trajectories substantially reduce overall mixing efficiency, particularly in mixers operating with reduced hopper volumes and limited installed power (Ferreira et al., 2024).

The results obtained in this study demonstrate that controlled shear redistribution of the upper feed layer provides a viable alternative to conventional lifting-and-collapsing mixing mechanisms. Unlike traditional approaches focused primarily on increasing screw rotational intensity, the proposed leveling device improves circulation stability of the feed mass without increasing mechanical loading on the working bodies.

Experimental observations showed that interaction of the leveling device with the upper fibrous layer contributes to reduction of localized compaction zones and stabilization of internal feed flow trajectories. Similar tendencies have been reported in recent studies devoted to rheological behavior and energy-efficient redistribution of fibrous biomass materials during mechanical processing (Wang et al., 2022; Navarro et al., 2022; Ferreira et al., 2024).

The results obtained in this study confirm the feasibility of transitioning from the conventional lifting-and-collapsing mechanism to controlled feed mass redistribution through leveling. This approach enables more uniform mixing at lower energy consumption without compromising feed structure (Zhou et al., 2023; Kim et al., 2021; García et al., 2003; Ahmed et al., 2023).

Reduction of the coefficient of variation and simultaneous decrease in specific energy consumption observed during the experiments indicate that controlled redistribution of the feed layer improves both mixing homogeneity and energetic efficiency of the process. This finding is particularly important for small-scale feed preparation systems, where installed drive power and operational energy resources are limited.

4.2. Practical interpretation of results for small farms

The obtained results have direct practical relevance for small farms operating under limited available power and reduced feed batch volumes. Under such conditions, traditional intensification methods based on increased drive power are economically inefficient.

Use of the leveling device allows adaptation of the feed preparation process to real operating conditions of small-scale machines. Improved feed mixture uniformity is achieved without increasing installed drive power or complicating machine design.

Reduced specific energy consumption and more stable loading of drive components also create favorable conditions for longer service life and reduced maintenance costs, increasing practical feasibility of implementation in small farming systems.

From a practical standpoint, reduction of stagnant zones and improvement of feed mixture homogeneity may contribute to more stable feed intake and improved distribution of nutritional components within the total mixed ration. Preservation of the physical structure of fibrous feed components is also important for maintaining physiological feeding efficiency in livestock production systems.

Therefore, the proposed leveling device may be considered a promising engineering solution for improving technological reliability and energy efficiency of feed preparation systems operating under conditions typical of small livestock farms.

5. Conclusion

The conducted theoretical and experimental investigations demonstrated that the traditional lifting-and-collapsing mixing mechanism used in small-scale screw feed mixer-dispensers has limited efficiency under conditions of reduced hopper volume and low feed mixture mass. A significant portion of drive energy is consumed for repeated lifting of the feed mass and overcoming friction forces, which increases specific energy consumption without ensuring sufficient mixture uniformity.

The performed analysis confirmed that redistribution processes in moist fibrous feed mixtures are strongly influenced by rheological behavior, local compaction, and resistance to shear deformation, which significantly affect circulation stability and energy dissipation during mixing.

Installation of the leveling device changes the feed mixing mechanism by introducing controlled redistribution of the surface feed layer through shear and cutting deformations without lifting the entire feed volume. This allows feed leveling to be considered an independent technological stage of the mixing process.

Experimental results showed that the leveling device eliminates stable zones of feed accumulation, improves feed mass redistribution across the hopper, and ensures achievement of required feed mixture uniformity within shorter mixing time.

Application of the leveling device increased feed mixture uniformity from 83.2% to 90.6%, reduced the coefficient of variation from 16.8% to 9.4%, decreased specific energy consumption from 5.3 to 4.2 kWh/t, and reduced mixing time from 12 to 8 min under the investigated operating conditions.

Comparative energy analysis confirmed that the leveling device reduces specific energy consumption by decreasing the share of energy required for vertical feed movement and reducing internal friction losses during mixing.

Statistical analysis confirmed that the obtained differences between the investigated machine configurations were statistically significant at p < 0.05, which indicates stable reproducibility of the observed technological effects.

The proposed approach improves feed mixture uniformity while preserving the physical structure of roughage, which is important for maintaining optimal feed quality under small farm operating conditions.

The obtained results confirm the practical feasibility of implementing leveling devices in small-scale feed mixer-dispensers and demonstrate their potential for improving energy efficiency and technological reliability of feed preparation systems for small farms.

The proposed technical solution may be considered a promising direction for further development of energy-efficient feed preparation technologies intended for livestock farms operating under conditions of limited installed power and reduced feed batch volumes.

Acknowledgements

The authors declare that no external funding was received for this study. The authors also declare no conflict of interest.

Data Availability Statement

The data used in this study are available from the corresponding author upon reasonable request.

References

• ABILZHANULY, T., ISKAKOV, R., ABILZHANOV, D., GULYARENKO, A. and KHAN, V., 2024. Justification of parameters of impact-spreading finger shaft for grinder–mixer–dryer using the example of eggshells. Eastern-European Journal of Enterprise Technologies, vol. 3, no. 1 (129), pp. 33-44. https://doi.org/10.15587/1729-4061.2024.304127
  » https://doi.org/10.15587/1729-4061.2024.304127
• AHMED, M., RAHMAN, S. and ISLAM, T., 2023. Evaluation of mixing quality and energy efficiency in total mixed ration systems. Agricultural Engineering International: CIGR Journal, vol. 25, no. 2, pp. 89-101.
• ALEXANDROV, A.I., 2020. Improvement of the mixing process in the production of highly digestible compound feeds with multienzyme complexes Voronezh, Russia: Voronezh State Agricultural University. PhD thesis.
• BRAGINETS, S.V., KHLYSTUNOV, V.F., BAKHCHEVNIKOV, O.N., ALFEROV, A.S. and CHERNUTSKY, M.V., 2016. Investigation of the feed component mixing process in a horizontal mixer. Processes and Machines of Agroengineering Systems, vol. 27, no. 3, pp. 110-113. In Russian.
• BRIDGEMAN, J., 2012. Mixing of particulate solids: principles and applications. Powder Technology, vol. 221, pp. 24-38.
• CHEN, K., LIU, P. and ZHAO, Q., 2023. Effect of screw configuration on particle redistribution in feed mixing systems. Applied Engineering in Agriculture, vol. 39, no. 4, pp. 517-526.
• DA BORSO, F., CHIUMENTI, A., SIGURA, M. and PEZZUOLO, A., 2017. Influence of automatic feeding systems on design and management of dairy farms. Journal of Agricultural Engineering, vol. 48, pp. 49-52. https://doi.org/10.4081/jae.2017.642
  » https://doi.org/10.4081/jae.2017.642
• DE KONING, C.J.A.M., 2010. Automatic milking and automatic feeding in dairy farming. Biosystems Engineering, vol. 106, pp. 121-129.
• FERREIRA, D., SILVA, R. and COSTA, P., 2024. Particle flow dynamics and energy dissipation in screw-type biomass mixers. Powder Technology, vol. 428, pp. 118795.
• FROLOV, V.Y. and SYSOEV, D.P., 2011. Optimization of the feed preparation process using a mixer-distributor. Machinery and Equipment for Rural Areas, no. 2, pp. 22-23.
• GARCÍA, A., PÉREZ, M. and TORRES, F., 2003. Energy-efficient feed preparation technologies for small-scale livestock farms. Agriculture, vol. 13, no. 7, pp. 1412.
• GOLIKOV, V.A., ARTAMONOV, V.N., USMANOV, A.S., RZALIEV, A.S., TAMAROVSKY, M.V. and AMANZHOLOV, K.Z., 2014. System of technologies and machines for feed harvesting, preparation and distribution at cattle feedlots Almaty: Publishing House, 142 p. In Russian.
• HALACHMI, I., 2009. Design of optimal robotic milking barns: a review. Journal of Dairy Science, vol. 92, pp. 1061-1074.
• HEINRICHS, A.J. and KONONOFF, P.J., 2002. Evaluating particle size of forages and TMRs using the Penn State Particle Separator. Journal of Dairy Science, vol. 85, pp. 1478-1486.
• KIM, S., LEE, D. and PARK, J., 2021. Influence of shear deformation on mixing homogeneity of fibrous feed materials. Journal of Agricultural Engineering Research, vol. 68, pp. 102-114.
• KURKOV, Y.B., BURMAGA, A.V., KRASNOSHCHEKOVA, T.A., SHARVADZE, R.L. and PEREPELKINA, L.I., 2019. Theoretical studies of the feed mixing process using mobile feed distributors. Far Eastern Agrarian Bulletin, no. 4, pp. 60-65. https://doi.org/10.22450/1999-6837-2019-4-60-65
  » https://doi.org/10.22450/1999-6837-2019-4-60-65
• LEONARDI, C. and ARMENTANO, L.E., 2003. Effect of quantity, quality, and length of alfalfa hay on selective consumption by dairy cows. Journal of Dairy Science, vol. 86, no. 2, pp. 557-564. https://doi.org/10.3168/jds.S0022-0302(03)73634-0 PMid:12647962.
  » https://doi.org/10.3168/jds.S0022-0302(03)73634-0
• LI, X., CHEN, Y. and HUANG, Z., 2024. Optimization of low-power feed mixing systems for small farms. Agricultural Systems, vol. 216, pp. 103912.
• MERTENS, D.R., 1994. Regulation of forage intake. In: G.C. FAHEY JUNIOR, eds. Forage quality, evaluation, and utilization Madison, WI, USA: ASA-CSSA-SSSA, pp. 450-493. https://doi.org/10.2134/1994.foragequality.c11
  » https://doi.org/10.2134/1994.foragequality.c11
• NAVARRO, J., RUIZ, P. and DELGADO, M., 2022. Mechanical behavior of moist fibrous agricultural biomass during mixing and transport. Journal of Terramechanics, vol. 104, pp. 12-21.
• POVALIKHIN, N.V. and KARPOV, V.P. Feed mixer-distributor Russian Federation. Patent No. 2563127. 2015. In Russian.
• SEMENIKHIN, A.M., SHVARTS, S.A. and DZREYAN, V.S., 2017. Substantiation of the methodology for selecting grinders–mixers–feed distributors. Bulletin of Agrarian Science of the Don, no. 1, pp. 68-75.
• SHI, Y., ZHAO, L., WANG, X. and LIU, H., 2023. Mixing performance and energy consumption analysis of horizontal TMR mixers. Biosystems Engineering, vol. 224, pp. 45-58.
• TSOY, Y.A., BAISHEVA, R.A. and PEREDNYA, V.I., 2018. Technological requirements and parameters of feed mixer-distributors for small farms. Innovations in Agriculture, no. 1, pp. 212-217.
• WANG, R., ZHANG, Y. and LI, J., 2022. Rheological behavior of fibrous biomass materials during mechanical mixing processes. Powder Technology, vol. 415, pp. 118-129.
• ZAVRAZHNOV, A.I. and ASTAPOV, S.Y., 2007. Reduction of energy consumption in the feed mixing process in a screw mixer-distributor. Bulletin of KrasGAU, no. 3, pp. 205-209.
• ZHOU, T., LI, W. and SUN, H., 2023. Modeling circulation stability in horizontal screw feed mixers. Computers and Electronics in Agriculture, vol. 205, pp. 107628.

Edited by

• Editor:
  Takako Matsumura Tundisi

Publication Dates

• Publication in this collection
  27 July 2026
• Date of issue
  2026

History

• Received
  13 Apr 2026
• Accepted
  20 May 2026