Development of Drying–Grinding–Extrusion Technology for Camel Compound Feeds Enriched with Wormwood

Abstract

This study investigated the drying–grinding–extrusion processing of camel compound feeds enriched with locally available botanicals. A 2 × 2 × 3 full factorial design was applied to evaluate the effects of infrared drying temperature (two levels), grinding time (two levels), and extrusion screw speed (three levels) on process efficiency and product quality. Moisture calibration was performed using gravimetric reference values. Drying kinetics were modeled with Page and Midilli equations, while specific energy consumption (SEC) and specific moisture extraction rate (SMER) were calculated. Particle-size distribution, extrusion parameters, and extrudate properties (expansion ratio, bulk density, water absorption index (WAI), water solubility index (WSI), hardness, and color) were analyzed. Infrared drying resulted in faster moisture removal and greater energy efficiency compared with convective drying. The Midilli model provided the best fit to drying kinetics data. The results indicate that optimized combinations of drying, grinding, and extrusion conditions can enhance the technological and nutritional potential of camel compound feeds; however, biological validation is required. Limitations: These findings are limited to processing and compositional outcomes; biological validation in camels (in vivo or in vitro) remains necessary to confirm effects on digestibility, health, or performance.

1. Introduction

The dromedary camel, traditionally a grazing animal in arid and semi-arid systems, is increasingly managed under semi-intensive conditions to meet rising demand for milk and meat. Interest in formulated compound feeds is growing, yet recent systematic assessment highlights methodological gaps in camel feeding studies and the need for more rigorous, standardized approaches to ration design and reporting [1]. Feed costs remain the largest share of production expense in ruminant systems, motivating process innovations that improve nutrient utilization and reduce energy use across grinding, thermal shaping (pelleting/extrusion), and drying steps.

Size reduction (grinding) increases surface area and can improve starch and protein utilization; process choices must balance target particle size with throughput and heat load. Contemporary feed-processing reviews document that pelleting and extrusion can enhance uniformity and digestibility of cereal-based diets, although responses depend on raw material and severity of treatment [2]. In ruminants, recent in vitro/analytical work comparing heat treatments of corn shows that extrusion is the most severe among common methods (pelleting, steam-flaking, micronization, extrusion), producing extensive starch transformation that is expected to accelerate ruminal degradation [3]. A 2023 meta-analysis in dairy cattle further indicates that extruded ingredients can increase nutrient digestibility and milk yield, while modifying volatile fatty acid profiles; these benefits, however, vary with matrix, degree of processing, and diet context [4]. Trials with extruded oilseeds also demonstrate productive responses and milk fatty-acid enrichment, supporting the relevance of extrusion settings for ruminant performance.

Post-processing drying is critical for shelf-stability of high-moisture ingredients and extrudates. Conventional hot-air drying is effective but energy-intensive; infrared drying offers faster surface heating via direct radiation absorption, often shortening drying time and limiting thermal damage [5]. Energy performance is commonly quantified by specific energy consumption (SEC) and specific moisture extraction rate (SMER). In a hybrid infrared drying–hot-air system, optimization studies report large SEC reductions and favorable SMER relative to convection alone, illustrating the potential of infrared drying integration for energy-efficient dehydration of biomass-like matrices relevant to feed manufacturing [6]. Beyond energy, infrared drying approaches have been expanded and reviewed with emphasis on heating uniformity, shorter processing time, and product quality retention in food/agro materials, trends that are transferrable to feed particles of similar size and composition [5].

In camels, however, the justification for extrusion requires particular consideration. Unlike monogastric species or high-producing ruminants, camels have adapted to low-quality forages and fibrous diets [7]. While starch gelatinization and improved digestibility can be beneficial for energy supply, excessive levels of rapidly degradable starch may reduce rumen pH and disturb fermentation balance. Therefore, extrusion in camel feeding should be regarded not as a universal enhancer, but as a controlled processing tool to improve nutrient accessibility without compromising rumen health. This highlights the importance of carefully optimizing processing parameters when designing functional compound feeds for camels.

Designing efficient infrared drying requires kinetic modeling of moisture ratio vs. time. Thin-layer models—especially Page and Midilli–Kucuk—remain state of-the-art for fruit/leafy/agro matrices, frequently achieving R² > 0.95–0.99 in recent datasets under convective or infrared drying-assisted regimes [8,9]. Fitting these models enables comparison of drying routes, estimation of effective diffusivity/activation energy, and calculation of SEC/SMER under practically relevant geometries.

Together, these advances motivate an integrated approach to camel compound feed technology: (i) select grinding that achieves the target particle-size distribution without excessive nutrient losses; (ii) apply extrusion settings that optimize functional and nutritional traits of cereal–botanical blends for ruminant digestion; and (iii) employ infrared drying to minimize energy use while controlling product quality. The present study, therefore, quantifies infrared drying kinetics (Page/Midilli fits), reports energy indices (SEC, SMER), and evaluates grinding—extrusion parameters for camel-relevant ingredients, addressing the evidence gap identified in contemporary camel feeding literature [1,4].

2. Materials and Methods

2.1. Materials and Experimental Design

The raw materials used in this study were sprouted triticale (KazNIIZhIK LLP, Almaty, Kazakhstan), camelthorn (Alhagi pseudalhagi) (cultivated in Shaulder, Turkistan Region, Kazakhstan), and wormwood (Artemisia lerchiana) (collected in the Almaty Region, Kazakhstan). These components were selected as functional ingredients for camel compound feeds due to their high biological activity and adaptation to arid conditions. The experiments were designed to evaluate drying and grinding regimes for these materials. A 2 × 2 × 3 full factorial design was applied, with two infrared drying temperatures (55 and 65 °C), two grinding times (3 and 5 min), and three extrusion screw speeds (250, 300, and 350 rpm). Each treatment combination was tested in five independent replicates (n = 5), with 100 g feed batches prepared under identical conditions. Treatments were randomized and blocked by day to minimize environmental variation.

Data were analyzed by full-factorial ANOVA, including all main effects and two- and three-way interactions. Model assumptions were verified using the Shapiro—Wilk test (normality) and Levene’s test (homogeneity). Effect sizes were reported as partial η², and significant effects (p < 0.05) were further explored using Tukey’s HSD test. Statistical analyses were conducted in STATISTICA 13.5 (TIBCO Software Inc., Palo Alto, CA, USA). An a priori power analysis (GPower 3.1, α = 0.05, medium effect size f = 0.25) confirmed that this design provided >80% power (1 − β ≥ 0.82) to detect main effects on the primary endpoints (final moisture, SEC, SMER, expansion ratio). Results are expressed as mean ± SD, with error bars in figures representing standard deviations of replicate values.

2.2. Moisture Measurement and Calibration

Initial moisture content was measured gravimetrically (oven drying at 105 °C) following ISO 5537:2004/IDF 26:2004 [10]. These results served as reference values to calibrate a grain moisture meter (Pfeuffer HE 50 Pfeuffer GmbH, Kitzingen, Germany). Calibration quality was assessed by R², RMSE, and bias. (Note: the moisture meter was used only for monitoring during drying, not as the primary measure).

Calibration results showed high agreement between the oven reference and the Pfeuffer HE 50 moisture meter (R² = 0.993; RMSE = 0.85%; bias = −0.2%). This confirms that the grain-type meter provided reliable monitoring values, although gravimetric data were used as the reference standard.

2.3. Drying Kinetics and Energy Indices

Thin-layer drying experiments were conducted under either infrared irradiation or forced-air convection (control). Samples (spread in ~1–2 mm layers) were dried at target temperatures while moisture loss was tracked by periodic weighing. At each time point, subsamples were oven-dried at 105 °C (24 h) to determine actual moisture content. Moisture ratio (MR) data were fitted to the Page and Midilli models by nonlinear regression. Goodness-of-fit was evaluated by R², RMSE, and chi-square (χ²). The Midilli model provided the best description of the drying kinetics. Energy performance was quantified by specific energy consumption (SEC, kWh per kg water removed) and specific moisture extraction rate (SMER, kg water removed per kWh). Air temperature, relative humidity, and infrared irradiance were logged continuously. Detailed time-series data were provided in the Supplementary Materials and mean drying curves (moisture vs. time) were plotted in Section 3.

2.4. Grinding

The ground material’s particle size distribution was determined by sieve analysis (ISO 3310-1). From this, the geometric mean diameter (GMD), geometric standard deviation (GSD), and percentiles (d10, d50, d90) were calculated and expressed as mean ± SD. Three mills were compared: the FRITSCH Analysette 3 vibratory sieve mill, the IKA A11 Basic impact mill, and the PD-400 disk mill. Each grinding test was carried out in five replicates. The PD-400 showed the best balance of throughput and fineness. For all mills, the outlet temperature of ground samples was measured with a thermocouple (±0.1 °C accuracy); the PD-400 demonstrated minimal temperature rise (<1 °C), confirming the absence of heat damage under normal operation.

2.5. Extrusion

Prepared feed mixtures (control and with wormwood/camelthorn additives) were extruded using a single-screw extruder (PD-400, Voronezhselmash, Voronezh, Russia) with a 7 cm diameter die. Barrel temperatures were set to approximately 50, 50, 80, and 120 °C across the extrusion zones to induce starch gelatinization. Screw speeds (250–350 rpm) and feed rates (~60 kg/h) were controlled, and torque was recorded to calculate specific mechanical energy (SME, kJ/kg). The resulting extrudates were analyzed for expansion ratio (die to extrudate diameter), bulk density (g/cm³), hardness (texture analyzer), water absorption index (WAI), water solubility index (WSI), and color (CIELAB L*, a*, b*). Extrudate microstructure was examined by scanning electron microscopy (SEM).

2.6. Nutrition

Target and actual macro- and micronutrient levels (for example, the Ca:P ratio) were compared in the feed formulations. The composition of the vitamin-mineral premix was documented. Recovery of vitamins and other bioactive compounds was calculated by simple mass balance (in mg, IU, or retinol equivalents).

2.7. Practical Size

The particle size distribution of the ground materials (sprouted triticale and camelthorn) obtained using the PD-400 grinder (Voronezhselmash, Voronezh, Russia). was determined. For sprouted triticale, after one pass through the PD-400, the material was sieved using circular test sieves with mesh sizes of 2 mm and 0.5 mm on a vibratory shaker (ISO 3310-1 standard) [11] operating at 50 Hz frequency and 1.5 mm amplitude for 10 min. The average particle diameter was then calculated. The average particle size was ~1.15 mm for triticale and ~1.07 mm for camelthorn. These values fall within the optimal range (approximately 1.0–1.2 mm) for compound feed manufacturing, according to equipment specifications and feeding standards.

2.8. Feed Formulation and Processing

Three compound feed variants were formulated for the feeding trial: one control diet and two experimental diets (Sample 1 and Sample 2) differing in the inclusion of wormwood and camelthorn. The control feed contained no wormwood, whereas Sample 1 and Sample 2 diets included 10% and 15% wormwood (Artemisia lerchiana) by weight, respectively. Camelthorn shrub (Alhagi pseudalhagi) was used as a major fiber source at 25% of the mix in the control and Sample 1, and at 17.5% in Sample 2. All diets were composed of the same locally available ingredients—dried wormwood herb, dried camelthorn, sprouted triticale grain, barley grain, wheat germ, sunflower seed press cake, sunflower meal, wheat bran, salt, and a vitamin–mineral premix—mixed in different proportions (

Table 1. Ingredient composition of the control and experimental compound feeds for lactating camels (percentage of total dry matter). Sample 1 and Sample 2 diets contained 10% and 15% wormwood, respectively.

Ingredient	Control (%)	Sample 1 (%)	Sample 2 (%)
Wormwood herb (Artemisia)	0	10	15
Camelthorn shrub (Alhagi)	25	25	17.5
Sprouted triticale grain	25	25	17.5
Wheat germ	10	5	10
Barley grain	10	10	15
Sunflower seed press cake	10	5	8
Sunflower meal (solvent)	10	10	5
Wheat bran	8	8	10
Salt	1	1	1
Premix (2% vitamin-mineral mixture)	1	1	1
Total	100	100	100

). These formulations were designed to be isocaloric and isonitrogenous, while increasing the level of bioactive plant additives (wormwood and camelthorn) in the experimental groups.

The relevance of including camelthorn and wormwood in compound feeds is supported by recent work showing that camels under semi-extensive production systems exhibit high selectivity in feed intake and energy expenditure, emphasizing the importance of balanced and palatable rations [12]. Furthermore, feed scarcity and seasonal variation in natural forage availability remain major challenges in camel husbandry, which underscores the role of compound feeds in ensuring year-round nutrient supply [13].

The formulation of each ration was carried out using the Korm Optima Expert software (version 3.5, KormoResurs, Voronezh, Russia), which balances feed recipes according to the nutritional requirements of lactating camels and established feeding standards [14]. This software-assisted approach optimized the ingredient levels to meet target crude protein, fiber, energy, vitamin, and mineral requirements while minimizing cost. After formulation, the feed ingredients were thoroughly mixed and the mixtures were processed by extrusion using a PE-170 grain extruder. According to the extruder’s technical specifications (GOST 13508–78) [15], the feed mash was exposed to high temperature and pressure, producing expanded pellets with uniform distribution of the wormwood and camelthorn additives. The high-temperature short-time extrusion process promotes starch gelatinization and may contribute to improved hygienic quality and potential digestibility of the feed, although further validation under animal feeding trials is required.

Finally, the compound feed samples (control and experimental) were analyzed for their basic chemical composition to confirm nutrient levels. Moisture content, crude protein, crude fiber, calcium, and phosphorus were determined according to standard methods (following relevant State Standard GOST protocols for feed analysis). For instance, dry matter was measured by oven-drying at 105 °C, crude protein by the Kjeldahl nitrogen method (N × 6.25), crude fiber by gravimetric method after sequential acid/alkali digestion, and Ca and P contents by standard wet-chemistry procedures. All analyses were performed in triplicate for each sample to ensure accuracy and compliance with quality standards.

2.9. Statistical Analysis

An a priori power analysis was conducted using GPower 3.1, assuming α = 0.05 and medium effect size (f = 0.25). All experimental treatments were carried out in five independent replicates (n = 5).With five replicates per treatment cell (n = 5), the design provided >80% statistical power (1 − β = 0.82) to detect main effects in the factorial ANOVA. Data from factorial treatments were analyzed by full-factorial ANOVA with all main effects and two- and three-way interactions. The model included drying method, grinding time, screw speed, and their interactions. Model assumptions (normality of residuals via Shapiro–Wilk; homogeneity via Levene’s test) were verified. Significant effects (p < 0.05) were followed by Tukey’s HSD multiple comparisons. Effect sizes were reported as partial η². All statistical procedures used STATISTICA 13.5 (TIBCO, Palo Alto, CA, USA). An a priori power analysis (GPower 3.1) confirmed that n = 5 per cell provided >80% power for detecting main effects on key outcomes (final moisture, GMD, SME).

3. Results

3.1. Drying Methods

Drying of plant raw materials is an important process in the feed, food, and pharmaceutical industries. Proper drying preserves products for long periods, prevents spoilage, and facilitates transportation. An important aspect is selecting a suitable drying system and optimal conditions (temperature, humidity, airflow). In this study, we focused on two common drying methods and ways to optimize the process for sprouted triticale and camelthorn [16]. The two drying methods examined were infrared drying using the Basic Station 3 (UkrSushka, Dnipro, Ukraine) and convective hot-air drying in a Daihan Scientific oven (Daihan Scientific, Seoul, Republic of Korea). Each method has specific features affecting process efficiency and feed quality preservation. According to the GOST 34023–2016 standard [17], the target moisture content for triticale grain is 14%. For camelthorn, a safe moisture content is in the range of 12–15% based on literature data. To reach these target moisture levels, we selected drying equipment that ensures effective yet gentle dehydration without destroying the feed’s valuable nutritional components.

Before drying, the initial moisture contents were 36.2% for sprouted triticale and 33.2% for camelthorn.

According to the results presented in

Table 2. Moisture content of sprouted triticale during drying at different temperatures (30 °C, 35 °C, 45 °C, 55 °C) using infrared and convective methods (mean values, % wet basis, measured every 30 min).

Indicators	Methods
	Infrared Drying (T = 30 °C)	Infrared Drying (T = 35 °C)
0 min	36.2 ± 0.2	36.2 ± 0.2
30 min	35.8	33.1
60 min	33.0	28.9
90 min	30.0	27.5
120 min	27.9	25.8
150 min	25.1	24.3
180 min	22.5	23.0
210 min	21.7	22.3
240 min	20.3	19.2
270 min	-	-
Page R2	0.980	0.988
Page RMSE	0.023	0.016
Page χ2	0.0007	0.0003
Midilli R2	0.997	0.989
Midilli RMSE	0.008	0.016
Midilli χ2	0.0001	0.0004
SEC	283	265
SMER	0.004	0.004

, the drying process in the convective oven was notably slower than in the infrared dryer, confirming the higher efficiency of the Basic Station 3 infrared unit for this application. For example, at 45 °C the infrared dryer brought sprouted triticale down to 14% moisture in 270 min, whereas the oven required a higher temperature (55 °C) and still took 270 min to approach 14%. It was noted that achieving the target moisture content for sprouted triticale (14%) at 55 °C in the Daihan oven, and camelthorn (≈14.2%) at 35 °C in the oven, required relatively high temperatures. Such high heat can lead to degradation of vitamins, enzymes, and other nutrients. In contrast, the Basic Station 3 infrared dryer provided a faster and more gentle drying process. Therefore, the infrared dryer was selected as the preferred method for drying these plant materials.

The optimal drying parameters for each material were identified based on dehydration efficiency and product quality preservation. For sprouted triticale, the most effective regime was infrared drying at 45 °C for 270 min, which achieved the target moisture content of 14%. For camelthorn, the optimal drying condition was infrared drying at 35 °C for 270 min, yielding a final moisture content of ~14.2%. Although using higher temperatures could reduce drying time, they also risk causing loss of biologically active compounds and raw material quality. The chosen drying regimes provide effective dehydration without destroying valuable components, which is especially important for feed ingredients intended to retain nutrients. Thus, the selected parameters represent a balance between process efficiency and preservation of nutritional value.

Drying of sprouted triticale and camelthorn followed similar trends, with infrared drying showing a consistently higher efficiency compared to convective hot-air drying. The initial moisture was 36.2% (triticale) and 33.2% (camelthorn), respectively. In both species, infrared drying accelerated water removal and achieved safe storage moisture levels (~14%) under gentler temperature regimes. For sprouted triticale (Table 2), the optimal regime was infrared drying at 45 °C for 270 min, which reduced the moisture content to the target 14%. In contrast, convective drying at 55 °C required the same duration (270 min) but was less efficient and risked nutrient degradation. Drying curve modeling showed that the Midilli equation provided the best fit (R² up to 0.997, RMSE ≤ 0.008, χ² ≤ 0.0001), outperforming the Page model. Energy indices further confirmed the superiority of infrared drying: SEC values were lower (265–283 kWh/kg water removed) and SMER values higher (0.004 kg/kWh) compared with convection.

For camelthorn (

Table 3. Moisture content of camelthorn during drying at different temperatures (30 °C, 35 °C, 45 °C, 55 °C) using infrared and convective methods (mean values, % wet basis, measured every 30 min).

Indicators	Methods
	Infrared Drying (T = 30 °C)	Infrared Drying (T = 35 °C)
0 min	33.2 ± 0.2	33.2 ± 0.2
30 min	30.5	28.1
60 min	27.2	25.9
90 min	25.6	23.2
120 min	22.3	21.8
150 min	19.2	18.3
180 min	18.5	17.0
210 min	17.7	15.5
240 min	16.5	14.2
270 min	-	-
Page R2	0.980	0.992
Page RMSE	0.025	0.016
Page χ2	0.0008	0.0003
Midilli R2	0.994	0.993
Midilli RMSE	0.014	0.016
Midilli χ2	0.0003	0.0004
SEC	269	237
SMER	0.004	0.004

), the most effective condition was infrared drying at 35 °C for 270 min, yielding a final moisture content of ~14.2%. Camelthorn dried faster than triticale at comparable conditions, likely due to its lower initial water content. Again, the Midilli model provided an excellent description of drying kinetics (R² = 0.993–0.994). Energy efficiency was slightly higher than for triticale, with SEC ranging 237–269 kWh/kg water removed and SMER 0.004 kg/kWh.

Overall, infrared drying outperformed convective hot-air drying across both raw materials, allowing achievement of safe moisture content at lower temperatures and with reduced energy consumption. These parameters balance dehydration efficiency with nutrient preservation, making infrared drying the preferred method for preparing camel feed ingredients.

3.1.1. Drying Behavior of Raw Materials

Figure 1 illustrates the drying kinetics of sprouted triticale under infrared drying and oven drying at different temperatures (30–40 °C). Moisture content decreased more rapidly under infrared drying compared to oven drying, confirming the efficiency of infrared drying treatment. Values are presented as mean ± SD; different letters indicate significant differences (p < 0.05).

Figure 2 shows the drying kinetics of sprouted camelthorn at 30–40 °C under infrared drying and oven methods. As with triticale, infrared drying resulted in a faster reduction in moisture content, while oven drying proceeded more slowly. The infrared drying method demonstrated lower drying times at all tested conditions. Data are mean ± SD, with statistical differences (p < 0.05) indicated by superscript letters.

3.1.2. Energy Indices

Figure 3 presents the specific energy consumption (SEC, kWh/kg) and the specific moisture extraction rate (SMER, kg/kWh) for infrared drying and oven drying across a range of temperatures. Infrared drying showed consistently lower SEC and higher SMER compared to oven drying, highlighting its superior energy efficiency. Values are reported as mean ± SD.

Error bars represent SD. Bars with different letters differ significantly (p < 0.05).

3.1.3. Model Fitting and Statistical Evaluation

Figure 4 compares the coefficient of determination (R²) for the Page and Midilli models applied to triticale and camelthorn drying data. Both models achieved high R² (>0.95), with the Midilli model slightly outperforming the Page model in both cases. Values are mean ± SD.

Figure 5 shows the root mean square error (RMSE) values for the Page and Midilli models. The Midilli model consistently had lower RMSE values compared to the Page model, indicating a better fit to the experimental data. Values are presented as mean ± SD.

Figure 6 illustrates the chi-square (χ²) values for model fitting. As with RMSE, the Midilli model achieved lower χ² compared to the Page model, suggesting it provides a more accurate description of drying kinetics for both triticale and camelthorn. Data are mean ± SD.

Overall, energy analysis demonstrated the superior efficiency of infrared drying over conventional oven drying (Figure 3). Statistical modeling confirmed that the Midilli model provided the best description of drying kinetics, as reflected in consistently higher R² and lower RMSE and χ² values compared to the Page model (Figure 4, Figure 5 and Figure 6).

3.2. Grinding Methods

ANOVA results (Table S1) showed that all factors—drying method, grinding method, raw material, and grinding fineness—had significant effects on processing outcomes (p < 0.05). The strongest effects were the type of raw material and the grinding method (p ≤ 0.03), while drying method and grinding level also had significant impacts (p ≈ 0.015–0.02).

Three grinding devices were evaluated on sprouted triticale and camelthorn: a FRITSCH Analysette 3 vibratory mill, an IKA A11 Basic impact mill, and the PD-400 disk mill. Their operating principles, energy input, and productivity were examined to match the materials’ properties (post-drying moisture, fiber toughness) and meet throughput requirements. The PD-400 disk grinder emerged as the optimal choice. It processed approximately 1 kg of dry material per minute (~60 kg/h) and produced uniform output. After grinding with the PD-400, triticale moisture remained ~14% (within specifications, indicating no overheating), and camelthorn moisture also stayed within acceptable range. The PD-400 was both efficient and cost-effective for production-scale use.

Overall, the PD-400 provided the best combination of high productivity and energy efficiency. It consistently produced a fine, homogeneous grind. On average, the PD-400 yielded a particle size of about 1 mm from the dried materials. Measurements indicated a geometric mean diameter of ~1.1 mm at 1 kg/min throughput. In comparison, the smaller lab mills had much lower throughput or produced less uniform sizes. Therefore, the PD-400 grinder was selected for further development of the feed processing technology.

3.3. Particle Size Analysis

The particle size distribution of the ground feed was relatively uniform: the PD-400 grinder produced an average particle size of ~1.1 mm for both triticale and camelthorn. This fineness is considered optimal for camel feed, as it yields a uniform texture that facilitates mixing and pelleting while maintaining enough fiber structure to stimulate chewing. Such particle sizes support improved digestibility without adversely affecting rumen function.

3.4. Wormwood Additive Development

A biologically active additive was developed from wormwood (Artemisia lerchiana) to enhance the compound feed. Wormwood was selected due to its rich content of flavonoids, essential oils, tannins, inulin, vitamins, and microelements, all of which have antimicrobial, anti-inflammatory, and immunomodulatory properties. Inclusion of wormwood in animal diets is known to improve digestion and increase disease resistance [14].

Laboratory assays of the dried wormwood confirmed its high content of beneficial compounds. The samples contained approximately 2.21 ± 0.2% flavonoids, 0.89 ± 0.01% tannins, 0.21 mg/100 g vitamin A, and notable amounts of vitamins B₁, B₂, B₃, and B₅ (

Table 4. Biologically active composition of wormwood (Artemisia lerchiana) as determined by laboratory analysis (mean ± SD, n = 3).

Name of Indicators, Units of Measurement	Actual Results	Test Method Standard
Flavonoids, %	2.21 ± 0.2	GOST R 55312-2012 [18]
Tannins, %	0.89 ± 0.01	GOST 24027.2-80 [19]
Vitamin A, mg/100 g	0.21	Chromatographic method
Vitamin B1, mg/100 g	0.238 ± 0.047	GOST 31483-2012 [20]
Vitamin B2, mg/100 g	4.07 ± 1.71	GOST 31483-2012
Vitamin B3, mg/100 g	5.46 ± 1.09	GOST 31483-2012
Vitamin B5, mg/100 g	1.23 ± 0.246	GOST 31483-2012
Vitamin B6, mg/100 g	0.981 ± 0.196	GOST 31483-2012
Vitamin B9, mg/100 g	1.07 ± 0.214	GOST 31483-2012

Note: Wormwood is rich in flavonoids and contains measurable amounts of essential vitamins. The values above confirm that the drying process preserved these compounds to a large extent. The analytical methods are shown for reference (e.g., GOST standards for vitamin analysis).

).

These bioactive substances contribute to the feed’s antioxidant capacity and nutritional value. In particular, flavonoids have strong antioxidant and anti-inflammatory effects that strengthen animal immune systems [13,21,22]. Moderate levels of tannins can support gut health by reducing pathogenic microbes. Vitamins A and B are essential for metabolism and productivity (e.g., vitamin A for vision and immunity, B vitamins for energy metabolism).

To preserve these active compounds during processing, wormwood was gently dried and ground. Wormwood was air-dried at a relatively low temperature (~30 °C for ~210 min, determined in a preliminary trial—see

Table 5. Moisture content changes in wormwood during drying at 30 °C (moisture % at 30 min intervals).

Drying Method	Moisture Content of the Control Sample	Moisture Content Change (%) Every 30 min at 30 °C
		30 min	60 min	90 min	120 min	150 min	210 min
Drying Oven Daihan Scientific	27.4 ± 0.2	24.3 ± 0.1	22.1 ± 0.2	18.9 ± 0.02	16.4 ± 0.05	15.3 ± 0.01	14.5 ± 0.2

Note: Wormwood dried considerably faster under infrared, reaching ~17–18% in about 210 min at 30 °C, whereas the oven-dried wormwood was still above 20% moisture at that time. Extrapolation suggests that infrared drying at slightly higher temperature (e.g., 35 °C) could achieve the target ~14% moisture within 240–270 min (as indeed shown in Table 3, wormwood reached ~14.2% at 35 °C in the infrared dryer).

) to minimize loss of volatile oils and heat-sensitive vitamins. After drying, wormwood was ground using the FRITSCH Analysette 3 vibratory mill to a fine powder. The grinding parameters were optimized: 5 min of vibration at an amplitude of 3 A (with brief pauses to prevent heating) produced a fine, flour-like powder without overheating the material.

The resulting wormwood powder was incorporated into the feed formulation as a bioactive additive. A balanced ration was formulated using Korm Optima software (version 3.5, KormoResurs, Voronezh, Russia), based on the nutritional requirements of lactating camels and established feeding standards. This formulation optimized energy, protein, fiber, vitamin, and mineral content while maximizing inclusion of the wormwood additive for its functional benefits.

3.5. Extrusion Outcomes

As screw speed increased from 250 rpm to 350 rpm, the expansion ratio of the extrudates increased from 1.8 ± 0.1 to 2.3 ± 0.2 (p < 0.05), and bulk density decreased by 12%. Water absorption index (WAI) and water solubility index (WSI) did not change significantly across treatments. The extrudates exhibited acceptable hardness (12–15 N) and consistent color (L* ≈ 70) at all screw speeds, indicating stable product quality.

3.6. Compound Feed Formulation Results

Using the optimized processing methods (infrared drying and PD-400 grinding) and the wormwood additive, we produced three experimental batches of camel compound feed. These were formulated as: a conventional control feed, Sample 1 (an experimental feed with a moderate level of the additive), and Sample 2 (an experimental feed with a higher level of the additive). All feeds were further processed by extrusion (using a PE-170 grain extruder) to create a pelleted final product, ensuring homogenous distribution of ingredients and improved nutrient availability.

Among the three tested rations (control, Sample 1, and Sample 2), Sample 2 emerged as the most balanced and beneficial formulation for lactating camels. Sample 2 contained about 15% wormwood (as the bioactive additive) and also included ~25% camelthorn meal, with the remainder being conventional feed components (e.g., barley, wheat bran, oilseed cake, mineral premix). Its composition provided a higher crude fiber content (≈14% of dry matter) compared to the control, along with moderate starch and sugar levels. Importantly, Sample 2 had an optimal calcium-to-phosphorus ratio (around 1.5:1) that meets the mineral requirements of lactating camels.

Sample 2 also contained the highest concentrations of bioactive compounds, as intended. As shown in

Table 6. Nutrient and bioactive composition of experimental camel compound feed samples (Control, Sample 1 with 10% wormwood, and Sample 2 with 15% wormwood) (mean ± SD, n = 3).

Indicators	Control	Sample 1	Sample 2
Flavonoids, %	0.27	0.31	0.33
Tannins, %	0.42	0.41	0.42
Vitamin A, mg/100 g	1.23	1.86	2.84
Vitamin B1 (thiamine), mg/100 g	0.50	0.58	0.57
Vitamin B2 (riboflavin), mg/100 g	1.32	1.40	1.55
Vitamin B3 (PP, niacin), mg/100 g	3.68	3.95	4.40
Vitamin B5 (pantothenic acid), mg/100 g	0.83	0.85	1.01
Vitamin B6 (pyridoxine), mg/100 g	0.46	0.46	0.48
Vitamin B9 (folic acid), mg/100 g	0.09	0.11	0.10

, Sample 2 had the greatest flavonoid content (~0.33%) relative to Sample 1 (0.31%) and the control (0.27%).

The premix contributed ~1.2 mg/100 g of vitamin A to the control diet. The addition of wormwood increased this level to 2.84 mg/100 g in Sample 2, showing that phytogenic enrichment doubled the retinol equivalents relative to the premix-only baseline (Table 1).

Tannin content in Sample 2 was ~0.42%, similar to the control feed (0.42%) and slightly above Sample 1 (0.41%). More significantly, Sample 2 was enriched in vitamins: for instance, vitamin A was 2.84 mg/100 g in Sample 2, compared to 1.86 mg in Sample 1 and 1.23 mg in the control. Likewise, Sample 2 exhibited the highest levels of vitamins B₂, B₃, and B₅ among the three rations. These improvements in the nutritional profile are expected to enhance the feed’s biological value.

Overall, the attributes of Sample 2 suggest it may better support rumen fermentation, immune function, and productivity in camels compared with the other rations. The balanced Ca:P ratio and enriched mineral profile of Sample 2 address key requirements during lactation and reduce the risk of hypocalcemia. These nutrient levels are comparable to, or within the range of, values reported for commercial camel milking rations and experimental diets (e.g., studies in lactating camels where supplementing concentrate improved milk yield and composition) [1].

Furthermore, the antioxidant compounds derived from wormwood may help mitigate oxidative spoilage, potentially enhancing milk stability. However, extrapolation to in vivo performance should be made cautiously, and direct feeding trials are needed to validate these effects.

These findings demonstrate that incorporating local bioactive plants (wormwood and camelthorn) into camel feed is a practical way to enhance its nutritional and functional value.

Table 5 provides the drying curve for wormwood at 30 °C, illustrating its faster drying kinetics compared to the other materials (infrared vs. oven drying data for wormwood).

As shown in Table 6, Sample 2 achieved the highest levels of flavonoids, vitamin A, and certain B vitamins, reflecting the successful incorporation of the wormwood and camelthorn additives. Sample 1 had intermediate values (with a lower additive level), and the Control had the lowest bioactive compound levels. Notably, Sample 2 provides more than double the vitamin A of the control diet, which is beneficial given camels’ needs in intensive systems. The B-vitamin content is also generally higher in Sample 2, though some vitamins like B₁ and B₉ are similar across samples, likely because those were sufficient in the base diet.

4. Discussion

The results of this study confirm the high efficiency of infrared drying for preserving feed quality, compared to traditional convective drying. We established optimal parameters of 45 °C for 270 min for sprouted triticale and 35 °C for 270 min for camelthorn, which provide gentle dehydration while achieving the desired moisture content. These findings align with reports from other researchers. It has been demonstrated that combined infrared–hot air drying of yam tubers can reduce drying time by more than 30% compared with hot–air drying alone, while ensuring uniform moisture removal and maintaining product structure [23]. Furthermore, infrared drying of processed barley has been reported to improve energy efficiency, accelerate drying rates, and enhance structural preservation relative to conventional drying methods [6]. The findings of our study with triticale and camelthorn are in agreement with these reports, suggesting that infrared drying represents a superior technique for processing feed ingredients, as it shortens the drying duration and preserves heat-sensitive nutrients.

A key focus of our work was the preservation of bioactive compounds during drying. Previous studies have shown that infrared drying of sprouted chickpeas retains a significantly higher level of phenolic compounds (766.2 μg gallic acid/g) compared to convective drying (463.4 μg/g) [24]. This supports the view that lower drying temperatures combined with targeted infrared energy minimize nutrient degradation. In our study, the infrared-dried samples of triticale and camelthorn also retained their nutritional and functional components effectively, as evidenced by the maintained vitamin levels and the resulting feed quality.

Achieving the target moisture level (around 14%) is also critical for safe storage of feed. Our obtained moisture values for triticale and camelthorn fall within the 14–18% range recommended by international guidelines for forage drying [25]. This indicates that the drying regimes we selected are appropriate and meet general standards for feed preservation. By ensuring moisture is sufficiently low, we reduce the risk of mold growth and nutrient spoilage during storage.

The choice of grinding equipment was another important consideration. We found that the PD-400 disk grinder was most effective, which can be explained by its high throughput and compatibility with the material moisture. This choice is justified by criteria such as productivity, energy efficiency, and the ability to handle moderately moist material without clogging. The fine particle size (~1.1 mm) achieved by PD-400 grinding is in line with typical feed industry practice for ruminants; it produces a uniform, powder-like product that mixes well and can be pelleted. These selection criteria—high throughput and suitable particle size—justify the use of the PD-400 in a scaled-up production context and ensure a consistent feed texture.

Wormwood was highlighted in this study as a valuable additive. Our analysis confirms that wormwood is a rich source of natural antioxidants and vitamins. In dried wormwood processed under gentle conditions (e.g., 30 °C drying, fine grinding), we recorded approximately 2.2% flavonoids, 0.89% tannins, and significant amounts of vitamins A and B (see Table 5). This composition is consistent with other reports in the literature. For instance, it has been noted that dried Artemisia absinthium (wormwood) is rich in phenolic compounds and can exert anthelmintic effects in sheep [26]. Moreover, the inclusion of 5–10% wormwood in the diet has been reported to improve the crude protein content of roughages and to provide antioxidant and antimicrobial benefits. Our results are in agreement with these observations, supporting the hypothesis that wormwood-based additives can enhance metabolic functions and immune status in ruminants by supplying a diverse range of bioactive phytochemicals.

The baseline vitamin A level (1.23 mg/100 g) was provided almost entirely by the premix. Wormwood contributed an additional ~1.6 mg/100 g, leading to a final concentration of 2.84 mg/100 g in Sample 2. This indicates that both the premix and the botanical additive contributed substantially to the vitamin profile of the feed.

Previous studies in pigs and sheep have reported that supplementing diets with 4% Artemisia absinthium was associated with increased intake and apparent digestibility of dry matter, organic matter, and crude protein, without negative effects on mineral balance. These findings suggest that wormwood may have potential to influence performance and health in different species. By analogy, incorporating wormwood in camel diets (as in Sample 2) may support feed efficiency and could potentially affect milk yield and composition, given the ruminant-like fermentation system of camels. Nevertheless, such extrapolations should be interpreted with caution, and dedicated in vivo studies in camels are required to confirm these effects.

In processing the feed materials, our approach of combining gentle drying with controlled grinding proved effective in maintaining bioactive properties. Convective air drying at 30 °C for ~210 min helped minimize vitamin losses in wormwood far better than high-temperature drying would. The subsequent grinding on a vibratory sieve mill ensured a homogeneous powder. Such low-temperature processing is justified, as overheating during drying or extrusion could denature proteins and reduce digestibility [4]. By carefully controlling drying and grinding, our technology maintains the bioactive quality of the ingredients, which is crucial for the efficacy of the final compound feed.

When formulating the compound feeds, we evaluated the performance of three rations. The most balanced ration (Sample 2), containing 15% wormwood and 25% camelthorn, provided a higher fiber level (~14% DM) while keeping starch and sugar at moderate levels. This formulation choice is significant: higher fiber and moderated starch help prevent issues like subacute ruminal acidosis, which can occur in camels fed high-concentrate diets. The fiber from wormwood and camelthorn also likely stimulates chewing and saliva production, helping maintain rumen pH. Additionally, Sample 2 offered an optimal Ca:P ratio—a critical factor in camel diets to support milk production and prevent mineral imbalances.

We also included camelthorn (Alhagi) in the feed mixture (approximately 25% in Sample 2). Camelthorn is recognized as a drought-tolerant shrub rich in nutrients and antioxidants. It has been reported that the inclusion of Alhagi maurorum in diets of growing camels improved antioxidant status and reduced blood triglycerides and cholesterol, without negatively affecting growth [27]. This finding supports our use of camelthorn as a complementary additive to wormwood. The combination of wormwood and camelthorn in Sample 2 therefore provides a broad spectrum of vitamins (A, B-complex), phenolic compounds, and minerals, which collectively contribute to enhancing immune function and metabolic health in camels.

Overall, incorporating these local plant additives (wormwood and camelthorn), processed under optimized conditions, produced a compound feed with improved nutritional composition and potentially beneficial functional properties. Sample 2, with higher levels of fiber, bioactive compounds, and key micronutrients compared with the standard diet, may contribute to supporting milk productivity and animal health in lactating camels. These observations are in line with the broader trend in ruminant nutrition of exploring phytogenic feed additives as supportive measures for performance [28]. Our approach represents a novel application in the context of camels and addresses an existing gap in the development of specialized feeds for this species; however, further in vivo research will be required to confirm these expected benefits.

The results confirmed the advantages of infrared drying over oven drying for both triticale and camelthorn. Faster moisture removal under infrared drying is consistent with previous findings on infrared-assisted dehydration, which emphasize improved drying rates due to deeper heat penetration and reduced boundary resistance. The greater reduction in triticale compared to camelthorn can be attributed to differences in tissue structure and fiber content.

Energy analysis further highlighted the superiority of infrared drying. The significantly lower SEC and higher SMER values confirm its energy-saving potential and make it a promising method for sustainable feed processing. These findings align with literature emphasizing infrared drying as an eco-efficient technology in food and feed industries.

Model evaluation revealed that although both Page and Midilli models performed well, the Midilli model offered the best fit to experimental data, evidenced by higher R² and lower RMSE and χ² values. This agrees with earlier studies reporting the flexibility of the Midilli model in describing complex drying behaviors. Its improved performance indicates that nonlinear patterns of moisture removal in both triticale and camelthorn are more accurately captured by Midilli.

At the same time, the outcomes of our work should be interpreted in the broader context of recent advances in feed processing technologies. These findings are consistent with broader evidence reported in the recent literature, which emphasizes the complementary role of infrared drying, extrusion, and phytogenic supplementation in improving the nutritional quality and functional properties of compound feeds.

Recent studies have shown that infrared drying not only reduces energy use but also preserves phenolic compounds and vitamins more effectively than conventional hot-air methods [5,9]. Likewise, extrusion technology has been confirmed to improve pellet stability and nutrient digestibility, as well as milk yield in ruminants [4,28]. Our results on wormwood and camelthorn additives are also consistent with reports demonstrating the immunomodulatory and antioxidant effects of Artemisia extracts in lambs [26] and the positive impact of Alhagi maurorum on antioxidant status and blood metabolites in camels and lambs [27].

Thus, when viewed together, the combination of optimized infrared drying conditions, extrusion processing, and the inclusion of locally available phytogenic additives (Artemisia, Alhagi) provides a strong scientific basis for developing sustainable, high-quality feeds for camels. This integrated approach not only enhances the stability and bioactivity of compound feeds but also has the potential to improve health and productivity in ruminants, as confirmed by multiple in vivo studies [27,29].

5. Conclusions

Efficient infrared drying: Infrared heating at 35–45 °C for ~270 min effectively reduced the moisture of sprouted triticale and camelthorn to ≈14%, outperforming conventional hot-air drying in speed while maintaining gentle conditions.

Optimized grinding: A production-scale disk mill processed the dried materials at ~60 kg/h, yielding a uniform particle size around 1.1 mm (GMD), suitable for pelleting. The grinding did not appreciably increase feed moisture or degrade nutrients.

Bioactive-enriched formulation: Incorporating wormwood (10–15%) and camelthorn (17.5–25%) increased the levels of antioxidants and vitamins in the feeds. For example, the highest-additive diet contained ~0.33% flavonoids and approximately twice the vitamin A level relative to the control. These compositional changes may enhance the nutritional profile of the feed mix, although their biological significance requires further confirmation.

Balanced nutrition: The final feed formulations were isoenergetic and isonitrogenous (≈14% protein, 14% fiber, balanced Ca:P) and included functional benefits from the plant additives. The feeds are thus designed to meet lactating camels’ nutrient requirements.

These optimized processing regimes provide a practical framework for producing high-quality, additive-enriched camel feeds. Limitations: The conclusions are based on processing and compositional data; actual animal performance outcomes (e.g., digestibility, milk yield) require confirmation through in vivo feeding trials.