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Article

Marbling and Meat Quality of Kazakh Finewool Purebred and Suffolk × Finewool Crossbred Sheep on an Intensive Fattening Diet

by
Gulmira Kenenbay
,
Urishbay Chomanov
,
Zhanayna Kramsakova
* and
Arailym Abilda
LLP “Kazakh Research Institute of Processing and Food Industry”, Almaty 050000, Kazakhstan
*
Author to whom correspondence should be addressed.
Processes 2025, 13(9), 2874; https://doi.org/10.3390/pr13092874
Submission received: 12 August 2025 / Revised: 2 September 2025 / Accepted: 3 September 2025 / Published: 8 September 2025
(This article belongs to the Special Issue Feature Papers in the "Food Process Engineering" Section)
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Abstract

This study evaluated marbling and meat quality traits in lambs of three genotypes under a uniform high-energy fattening regimen. Male lambs (6–7 months old, n = 12 per group) from purebred Kazakh Finewool (control) and two independent Suffolk × Kazakh Finewool F1 crossbred lines (Groups 1 and 2) were fed identical diets and raised under the same conditions. Meat samples were analyzed for composition, fatty acid profile, micronutrients, color, visual marbling, and microbiological safety. Group 2 crossbreds had significantly higher intramuscular fat (~9.0%) than the controls (~6.5%) (p < 0.05), with corresponding increases in monounsaturated and polyunsaturated fatty acids. Vitamin A, vitamin E, and zinc levels were also higher in Group 2 (p < 0.05), while other nutrients were similar across groups. All samples had normal pH (~5.7–5.8) and high water activity (~0.985) and met microbial safety standards. Visual marbling was more pronounced in crossbreds, and meat color remained bright red with no significant group differences in redness (a value). These findings suggest that crossbreeding Kazakh Finewool with Suffolk sheep, combined with controlled grain fattening, enhances marbling and nutritional traits without compromising safety or appearance, offering a viable approach to improving lamb meat quality.

1. Introduction

Marbling—the intramuscular fat (IMF) deposited within muscle—is a key indicator of red meat quality because it contributes to flavor, juiciness, and tenderness. The extent of IMF deposition is influenced by both genetics and diet. Specialized high-energy finishing diets can promote muscle growth and intramuscular fat accumulation due to an optimal protein-to-energy ratio in the feed. For example, Joy et al. [1] and De Brito et al. [2] reported that diets enriched in protein and energy improved the fatty acid composition of lamb, increasing the proportion of polyunsaturated fatty acids and enhancing sensory properties of the meat. However, different breeds (and sexes) of sheep have inherently different propensities for fat deposition. Bartkiene et al. [3] found that lamb sex (in the Romanov breed) significantly affected muscle fatty acid profiles and lipid peroxidation, underscoring the need to account for genotype and sex in meat quality studies. Similarly, the review by Zhang and Huang [4] highlights that feeding systems and breed genetics both play critical roles in determining meat quality traits in small ruminants [5,6].
The Kazakh Finewool sheep is a local breed primarily raised for wool, with only moderate meat yield and marbling. Current trends in the sheep industry of Kazakhstan call for improving meat production traits of such local breeds. One strategy is crossbreeding with specialized meat breeds to combine the adaptability of local breeds with the superior growth and carcass traits of meat-type breeds. Suffolk sheep are a well-known meat breed characterized by high growth rates and a tendency for greater intramuscular fat deposition. Crossbreeding Kazakh Finewool ewes with Suffolk rams could potentially increase lamb growth performance and marbling through heterosis and complementary traits. Indeed, specialized meat breed crosses often yield heavier carcasses and improved meat quality compared to purebred local lambs [7]. However, the meat quality of such crossbreds under intensive feeding conditions needs comprehensive evaluation, including not only basic carcass traits but also chemical composition, lipid profile, and other quality parameters [8,9,10,11,12,13].
In this context, we aimed to assess the effects of Suffolk crossbreeding, under a controlled grain-fattening regimen, on lamb meat marbling and quality. We hypothesized that Suffolk × Kazakh Finewool crossbred lambs, when fed a high-energy diet under identical management conditions, would exhibit higher intramuscular fat and improved meat quality characteristics (e.g., more favorable fatty acid profile and nutrient content) compared to purebred Kazakh Finewool lambs, without compromising other quality attributes. To test this hypothesis, our study compared three genotypic groups (purebred vs. two Suffolk-cross lines) in terms of meat chemical composition, fatty acid profile, vitamin and mineral content, meat color, marbling score, pH, water activity, and microbiological safety [14,15,16,17,18].

2. Materials and Methods

2.1. Experimental Design and Animal Groups

The feeding trial was conducted in 2024 at the DALA FOOD LLP (Almaty region, Kazakhstan) production facility. The experiment used a completely randomized design with three genotypic groups of lambs raised and fattened under identical conditions. The groups were as follows:
  • Control (Purebred Kazakh Finewool)—12 intact male lambs of the Kazakh Finewool breed (a fine-wooled dual-purpose breed).
  • Group 1 (Crossbred Suffolk × Kazakh Finewool, line 1)—12 intact male F1 crossbred lambs produced by Suffolk rams mated with Kazakh Finewool ewes (first Suffolk × Finewool crossbreeding line).
  • Group 2 (Crossbred Suffolk × Kazakh Finewool, line 2)—12 intact male F1 crossbred lambs from a second Suffolk × Finewool crossbreeding line (an independent cohort of the same cross, using a different set of parent animals).
Each lamb was considered an experimental unit (n = 12 per genotype). All lambs were of similar age (~6–7 months old at the start of fattening) and had been weaned and grown under standard farm conditions prior to the trial. Before the specialized fattening began, the lambs were maintained on a conventional diet of pasture grazing and grass hay. No concentrates or high-energy supplements were given in the pre-fattening period beyond normal farm practice, ensuring that all lambs entered the trial with a comparable nutritional background.

2.2. Fattening Regimen and Housing

All groups were subjected to a specialized grain-based fattening regimen of 30 days. The lambs were housed indoors in the same barn under uniform conditions (ambient temperature ~18–20 °C, good ventilation, natural light cycle). They were group-housed by genotype in spacious pens (one pen per group) bedded with straw, providing approximately 2.5 m2 of floor space per lamb to ensure equal comfort and movement. Throughout the trial, management was standardized across groups: all lambs had free access to fresh water and were fed the same total mixed ration. Feed was offered ad libitum twice daily (morning and afternoon), and intake was monitored with feed refusals recorded daily to ensure that feed was always available (i.e., truly ad libitum feeding). Only minimal feed refusals were observed, indicating that the lambs could eat to appetite.
The diet consisted of a pelleted concentrate feed plus forage (alfalfa hay) in a ratio designed for intensive lamb fattening. The alfalfa hay (coarse roughage) was provided separately at a constant rate of 2.0 kg per head per day, while the pelleted compound concentrate constituted the high-energy portion of the diet. The formulated compound feed was identical for all animals and was prepared in two phases: Phase I (days 1–15) and Phase II (days 16–30). In Phase I, the concentrate had a higher inclusion of barley, whereas in Phase II the proportion of corn was increased, reflecting a shift to a more energy-dense feed in the latter half of fattening. The alfalfa hay and protein supplement levels remained constant across phases. Table 1 shows the ingredient composition of the concentrate feed per lamb per day. The concentrate was formulated to be approximately 16% crude protein and 11 MJ/kg metabolizable energy, with adequate fiber and fat levels for young meat lambs. Additionally, a vitamin–mineral premix was included in the concentrate formulation (approximately 1% of the mix, supplying essential fat-soluble vitamins and trace minerals) to ensure all micronutrient requirements were met. A sample of the final feed was subjected to proximate chemical analysis to verify that its actual nutrient content corresponded to the formulation. All groups received this isoenergetic and isonitrogenous diet, thereby minimizing nutritional variability between genotypes. This standardized feeding allowed observed differences to be primarily attributed to genotype rather than diet [19,20,21,22,23].
During the fattening period, lamb health and growth were monitored regularly. The lambs were not castrated (all males were intact) to maintain a uniform physiological status; this decision was made because intact males typically deposit less intramuscular fat than castrates; so using only intact males provided a consistent baseline for comparison across genotypes. At the end of the 30-day fattening, all 36 lambs were humanely slaughtered on-site at a commercial abattoir facility following standard veterinary regulations. The lambs were fasted for ~12 h prior to slaughter (with free access to water). Each animal was slaughtered according to industry best practices, including stunning (using a captive bolt device) and exsanguination, under the supervision of a veterinary inspector. After slaughter, carcasses were eviscerated and split in accordance with commercial procedures. The carcasses were then chilled at 0–4 °C for 24 h to allow rigor mortis resolution and to attain a uniform post-mortem temperature [24,25,26,27].
From each chilled carcass, we selected two muscles for analysis: the longissimus lumborum (loin eye muscle, along the lumbar spine) and the biceps femoris (outside thigh, part of the hind leg). The longissimus lumborum (a prime loin cut) was chosen as the representative muscle for detailed chemical and quality analyses. A section of the longissimus lumborum muscle (between the 1st and 3rd lumbar vertebrae) was excised from each carcass to serve as the primary sample for laboratory analyses. Additionally, a sample of the biceps femoris (a major hind leg muscle) was taken from each carcass to evaluate marbling and color in an anatomically different muscle. Both muscles were trimmed of external fat and connective tissue as needed.
Sample handling: Approximately 500 g of the longissimus muscle from each animal was subdivided for different analyses. For proximate composition, fatty acid, vitamin, and mineral analyses, subsamples of muscle were vacuum-packed, labeled, and immediately frozen at −20 °C until testing. These frozen samples were later thawed under refrigeration (4 °C) prior to analysis. For pH measurement, a portion of the longissimus muscle was kept fresh (never frozen); pH was measured at 24 h postmortem on these chilled samples (as described below). The biceps femoris samples were used primarily for visual appraisal and color measurement: cross-sectional slices (~2.5 cm thick) of both the longissimus and biceps femoris were cut and used for imaging and colorimetry on the day after slaughter. All equipment that came into contact with the meat was sterilized, and sample integrity was maintained by working quickly in a cold room (≤4 °C) to prevent deterioration.

2.3. Analytical Methods

Proximate Composition: Moisture, crude protein, intramuscular fat, and ash contents of the longissimus muscle were determined using standard AOAC methods [28,29,30,31,32,33,34]. Briefly, moisture was measured by oven-drying samples at 105 °C to constant weight (method 950.46B), protein by the Kjeldahl method (N × 6.25, method 992.15), fat by Soxhlet extraction with petroleum ether ((Merck KGaA, Darmstadt, Germany; method 991.36) [29], and ash by incineration in a muffle furnace at 550 °C (Nabertherm GmbH, Lilienthal, Germany method 920.153). The results were expressed as percent of wet tissue weight. The pH of the muscle was measured at 24 h postmortem using a portable pH meter with a spear-tip electrode (Testo 205, Testo SE & Co. KGaA, Lenzkirch, Germany) inserted into the longissimus muscle; the meter was calibrated with pH 4.00 and 7.00 buffers at 20 °C. Water activity (Aw) of the fresh muscle was determined on 2.5 cm thick samples using a LabMaster-aw hygrometer (Novasina AG, Lachen, Switzerland) at 25 °C.
Fatty Acid Analysis: Intramuscular fat (IMF) was extracted from ~10 g of muscle tissue using a chloroform–methanol solvent mixture (2:1, v/v) following the Folch et al. method [35]. The extracted lipids were converted to fatty acid methyl esters (FAMEs) by base-catalyzed transmethylation (KOH in methanol). FAMEs were analyzed by gas chromatography (GC) on an Agilent 6890 GC system (Agilent Technologies, Santa Clara, CA, USA) equipped with a flame-ionization detector (OpenLAB CDS ChemStation Edition, Version A.01.10, Agilent Technologies, Santa Clara, CA, USA) and a capillary column (DB-23, 60 m × 0.25 mm, 0.25 µm film; Agilent Technologies, Santa Clara, CA, USA). The GC oven was programmed for a temperature gradient from 50 °C to 230 °C to separate fatty acids. Individual FAMEs were identified by comparison of retention times with known standards (Supelco 37-component FAME Mix; Merck KGaA, Darmstadt, Germany) [36] and quantified as a percentage of total fatty acids by area normalization. Total saturated (ΣSFA), monounsaturated (ΣMUFA), and polyunsaturated (ΣPUFA) fatty acid percentages were calculated from the sum of the respective FAMEs.
Vitamin and Mineral Analysis: The concentrations of fat-soluble vitamins A and E in the meat were determined by high-performance liquid chromatography (HPLC). Retinol (vitamin A) and α-tocopherol (vitamin E) were extracted from 5 g meat samples using hexane after saponification, following AOAC Official Method 2007.04. The HPLC analysis employed a C18 reversed-phase column (250 mm × 4.6 mm, 5 µm; Agilent Technologies, Santa Clara, CA, USA) on an Agilent HPLC system (Agilent Technologies, Santa Clara, CA, USA) with UV-Vis detection (Agilent Technologies, Santa Clara, CA, USA). Retinol was detected at 325 nm and α-tocopherol at 292 nm. Vitamin concentrations were quantified by external calibration with pure standards and reported as mg per 100 g meat for vitamin E and µg per 100 g for vitamin A. Vitamin B12 (cobalamin) was determined using a microbiological assay (a growth response method using a Lactobacillus sp. as the indicator organism, as per AOAC Official Method 952.20). Each meat sample was homogenized and autoclave-extracted in phosphate buffer; then the extract was added to vitamin B12 assay medium inoculated with Lactobacillus delbrueckii subsp. lactis. After incubation, the growth (turbidity) was measured spectrophotometrically against B12 standards to quantify the vitamin. Results for B12 are expressed in µg per 100 g of meat. For mineral analysis, dried meat samples were ashed at 550 °C and dissolved in nitric acid; the solution was analyzed by atomic absorption spectroscopy (AAS) to determine iron (Fe) and zinc (Zn) content, and by colorimetry for calcium (Ca). Mineral concentrations are reported as mg per 100 g of meat.
Color Measurement: Meat color was assessed on the cut surface of the longissimus and biceps femoris samples 24 h postmortem. After a 30 min bloom period at 4 °C (to allow oxygenation of myoglobin), objective color values were measured using a portable Minolta Chroma Meter (CR-400, Konica Minolta, Tokyo, Japan) calibrated to a white standard tile. The CIELAB color space parameters were recorded: lightness (L), redness (a), yellowness (b), chroma (C = √(a2 + b2)), and hue angle (h = arctan (b/a)). For each muscle, three readings were taken at different locations and averaged. In addition to instrument measurements, high-resolution photographs of each sample were taken under standardized lighting for a visual record of marbling and color. A five-point visual marbling scale (from 1 = very low to 5 = abundant marbling) was used by three trained observers to score the marbling in each muscle, to complement the quantitative fat data.
Microbiological Analysis: To evaluate meat safety, microbiological tests were performed on fresh longissimus samples 24 h after slaughter. Total mesophilic aerobic bacteria (total viable count) were enumerated by plating meat homogenate dilutions on plate count agar (Merck, Darmstadt, Germany) and incubating at 30 °C for 72 h [37]. Enterobacteriaceae were counted by plating on violet red bile glucose agar (Merck, Darmstadt, Germany) and incubating at 37 °C for 24 h [38]. The results for these counts are reported as log10 colony-forming units per gram (CFU/g). The presence of pathogens was assessed by testing 25 g meat samples for Salmonella spp. [39] and 10 g samples for Staphylococcus aureus [40]; the results are reported as detected/not detected in the sample amount. All microbiological analyses were performed in a certified food testing laboratory under sterile conditions.
Statistical Analysis: Data were analyzed using SPSS Statistics v25.0 [41,42]. One-way analysis of variance (ANOVA) was used to test for genotype effects, with the lamb’s genotype (control, Group 1, Group 2) as the fixed factor. For variables measured on each lamb (e.g., chemical composition, fatty acids, color, etc.), the individual animal was the experimental unit. When ANOVA indicated a significant effect (p < 0.05), Tukey’s HSD post-hoc test was applied to compare group means. Visual marbling scores (ordinal data) were additionally confirmed with a non-parametric Kruskal–Wallis test [42], which yielded similar conclusions. The results are presented as mean ± standard deviation (SD). Differences were declared statistically significant at p < 0.05. Trends are mentioned for 0.05 < p < 0.10. In the tables, different superscript letters are used to denote significant differences between groups for that variable (p < 0.05).

3. Results

3.1. Carcass and Meat Composition

All lambs remained healthy throughout the 30-day fattening period. They started the trial at a similar live weight (approximately 34–36 kg on average) and reached about 42–44 kg after 30 days of fattening, gaining roughly 8 kg (≈270 g/day) over the period. Final live weights did not differ significantly among the three groups (p > 0.05), as expected under the uniform feeding regimen.
Table 2 summarizes the proximate composition and physicochemical traits of the longissimus lumborum muscle across the three genotypes. There were notable differences in moisture and fat content. Group 2 (crossbred) lambs had the highest intramuscular fat (IMF) content in the loin muscle at about 9.0%, whereas the purebred control group had the lowest fat (~6.5%). Group 1 crossbreds were intermediate (~8.0% fat). Statistical analysis confirmed a significant genotype effect on fat percentage (p < 0.05): the crossbred groups, particularly Group 2, accumulated more intramuscular fat than the control. Conversely, muscle moisture content was highest in the leaner control lambs (about 74.5%) and lowest in Group 2 (~70.5%), with Group 1 again intermediate (~72.0%). This inverse relationship between fat and moisture is expected, as higher fat deposition in muscle usually occurs at the expense of water content. Indeed, Group 2’s loin muscle contained significantly less water than the control’s (p < 0.05). Protein and ash contents of the loin were similar for all groups, around 17.5–18.0% protein and 1.1–1.3% ash, with no statistically significant differences (p > 0.05). This indicates that the increase in IMF in the crossbreds did not dilute the muscle’s protein concentration appreciably.
Muscle pH measured 24 h postmortem did not differ significantly among the groups (p > 0.05). The ultimate pH values ranged from 5.70 in the control to 5.80 in Group 2 (Table 2), all falling within the normal pH range expected for lamb meat (≈5.5–5.8). These pH values suggest that no unusual stress or glycogen depletion occurred before slaughter—all carcasses underwent normal postmortem acidification, indicating good meat quality in terms of freshness and shelf life potential. Similarly, water activity (Aw) of the fresh meat was high (0.985–0.987) and consistent across genotypes (Table 2), with no significant differences. An Aw close to 0.99 is typical for fresh, unaged meat and indicates that all samples were comparably moist. The combination of near-neutral pH and high Aw in all groups provides no especially favorable conditions for microbial growth, which is reflected in the microbiological results (discussed later).
The higher intramuscular fat in crossbred lambs (Groups 1 and 2) relative to purebreds is a central finding of this study. It suggests that introducing Suffolk genetics, along with intensive feeding, greatly enhanced the marbling potential of the lambs. This result is in agreement with prior reports that meat breed crossbreds tend to deposit more IMF than wool-breed lambs under the same diet. The observed differences in IMF also align with the visual marbling differences (see below). It is worth noting that despite the increased fat in crossbreds, their loin muscles still contained around 17–18% protein, indicating that the meat remained high in lean content.

3.2. Fatty Acid Profile of Intramuscular Fat

The fatty acid composition of the intramuscular fat from the loin is presented in Table 3. Across all groups, the fat was composed predominantly of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs), with a smaller proportion of polyunsaturated fatty acids (PUFAs), which is typical for ruminant meat lipids. The control group (purebred) showed a slightly higher total SFA fraction (ΣSFA ~39.5% of total fatty acids) compared to the crossbred groups (ΣSFA ~37.2% in Group 1 and ~35.0% in Group 2). Correspondingly, the crossbred lambs tended to have higher unsaturated fatty acid fractions. The total MUFA content increased from about 38.7% in the control to approximately 40–42% in the crossbreds. The total PUFA content was ~21.8% in the control vs. ~22.8% in Group 1 and ~23.5% in Group 2. Statistical analysis revealed that most of these differences were numeric trends that did not reach significance, except for PUFAs in Group 2: Group 2 had a significantly higher PUFA percentage in its intramuscular fat compared to the control (p < 0.05). Group 1’s PUFA level was intermediate and not significantly different from either the control or Group 2. Thus, the Suffolk crossbreds—especially those of line 2—achieved a modestly more favorable (more unsaturated) fatty acid profile in their muscle fat.
In terms of specific fatty acids, the crossbred lambs tended to have slightly lower palmitic acid (C16:0, a major SFA) and slightly higher oleic acid (C18:1, the predominant MUFA) and linoleic acid (C18:2 n-6, a key PUFA) compared to the purebred lambs. These shifts in individual fatty acids correspond to the observed differences in the total SFAs and unsaturated fat fractions. However, the changes in specific fatty acids were relatively small and, in most cases, not statistically significant.
Overall, the crossbred lambs’ meat fat can be characterized as slightly “healthier” in terms of fatty acid profile: they had a lower proportion of saturated fat and a higher proportion of unsaturated fats compared to purebred lambs. Although only the PUFA increase in Group 2 was statistically significant, the general trend is in line with expectations that a nutrient-dense diet and faster growth in crossbreds can enhance the deposition of unsaturated fats. Notably, Group 2 lambs had about 1.7 percentage points more PUFAs in their IMF than purebred lambs (23.5% vs. 21.8%); this difference, albeit modest, could improve the nutritional profile of the meat by increasing essential fatty acids. The higher PUFAs in Group 2 occurred without any reduction in beneficial MUFAs; in fact, Group 2 also had the highest MUFA percentage (~41.5%). In practical terms, a higher proportion of MUFAs and PUFAs (and correspondingly lower SFAs) is desirable for human diets, as it is associated with better lipid nutrition and potential health benefits (e.g., improved cardiovascular risk profile).

3.3. Vitamin and Mineral Content

The concentrations of key vitamins (A, E, B12) and minerals (Fe, Zn, Ca) in the lamb meat are shown in Table 4 (values per 100 g of raw muscle). The intensive grain diet supplemented with premix led to some between-group differences, especially for vitamin A, vitamin E, and zinc:
  • Vitamin A (retinol): The control lambs’ meat had the lowest vitamin A content at ~25 µg/100 g, whereas crossbred Group 2 had the highest at ~35 µg/100 g. Group 1 was intermediate (~30 µg). Statistical analysis indicates that Group 2’s vitamin A concentration was significantly greater than the control’s (p < 0.05). The ~40% increase in vitamin A for Group 2 suggests that genetic or metabolic differences (or perhaps slightly higher feed intake) in this group allowed more retinol deposition in muscle. Group 1’s value was not significantly different from the control in pairwise comparisons, but the overall trend was an increase in the crossbreds.
  • Vitamin E (α-tocopherol): A similar pattern was observed. The control meat contained ~1.0 mg vitamin E/100 g, while Group 2’s meat had ~1.4 mg/100 g, and Group 1’s had ~1.2 mg. Group 2 was significantly higher than the control (p < 0.05), reflecting about a 40% increase. Vitamin E is an antioxidant, and its higher level in crossbred meat could be beneficial for meat oxidative stability and nutritional value. The uniform diet, which included vitamin premixes, was given to all lambs; so the differences in vitamins likely relate to differences in feed utilization or tissue deposition between genotypes.
  • Vitamin B12 (cobalamin): All groups had similar B12 levels (~0.5–0.6 µg/100 g) with no significant differences (p > 0.05). These values are within expected ranges for lamb muscle, and the consistent result is unsurprising since B12 synthesis in ruminants is primarily via rumen microbes and would not be markedly affected by the slight genotype differences or the short-term feeding regime.
  • Iron (Fe): Iron concentrations in the meat were about 2.0–2.2 mg/100 g across groups, with no significant genotype effect. Lamb is known for being a good iron source; our results confirm that all groups provided roughly equivalent iron content, likely reflecting similar myoglobin levels given the similar age and feeding.
  • Zinc (Zn): Zinc showed a small but notable difference: control lambs had ~3.0 mg Zn/100 g, whereas Group 2 had ~3.3 mg/100 g. Group 1 was ~3.1 mg. Statistical analysis found that the crossbred Group 2 had a higher zinc content than the control (p < 0.05). This suggests that crossbred lambs might have had a slightly greater capacity or efficiency to incorporate zinc into muscle tissue (possibly due to higher growth rates or muscle mass). The differences are marginal in absolute terms, but they may still be nutritionally meaningful (around a 10% increase in Zn).
  • Calcium (Ca): Calcium levels were low (15–18 mg/100 g) and did not significantly differ between groups. Muscle foods are generally not a major calcium source, and our data align with that, showing only trace amounts of Ca in lamb meat across all genotypes.
Overall, the vitamin and mineral data indicate that the specialized grain diet (with added premix) provided ample micronutrients, and the Suffolk-cross lambs tended to deposit slightly more of certain nutrients (vitamin A, vitamin E, Zn) in muscle. All the groups’ values fall within reported ranges for lamb meat, demonstrating that the meat has a good nutritional profile. The slight enhancements in vitamins A and E for crossbreds could also confer improved oxidative stability (since vitamin E protects lipids from oxidation), which might be beneficial given the higher fat content in their meat.

3.4. Meat Safety and Microbiological Quality

Microbiological examination of the meat (Table 5) confirmed that all samples were of high microbiological quality and met food safety standards. The total mesophilic aerobic bacteria count (TMB), which is an indicator of the general bacterial load, was low in all groups: approximately 3.3–3.4 log10 CFU/g. There were no significant differences in TMB between the control and crossbred groups (p > 0.05). These counts (~2000 CFU/g) are typical for fresh, chilled lamb meat processed under hygienic conditions and indicate good initial cleanliness and cold-chain maintenance. Enterobacteriaceae counts were also very low, around 1.0–1.2 log10 CFU/g (i.e., on the order of 10 CFU/g) for all groups, with no group differences. Such low levels of Enterobacteriaceae (which include potential spoilage organisms and hygiene indicators) further demonstrate the effectiveness of sanitary handling during slaughter and processing. Importantly, no pathogens were detected in any of the samples. Specifically, Salmonella spp. was not isolated from any 25 g meat sample, and Staphylococcus aureus was not detected in any sample (0 CFU/0.1 g). The absence of Salmonella and S. aureus means the meat is safe from these common bacterial hazards. Additionally, as noted earlier, all groups had meat pH and AW values in the normal range, which do not favor rapid microbial growth; this likely contributed to the low microbial counts observed. There was no indication that the intensive grain fattening adversely affected microbial quality; on the contrary, some evidence in the literature suggests that higher fat content in meat can slow microbial spoilage, possibly by reducing water activity in tissues or through fat’s physical exclusion of water [21]. In our study, Group 2 (which had the highest IMF) did not show any higher bacterial counts than the leaner control, which is consistent with that notion, although all groups were tested fresh; so differences might not manifest without storage time.
In summary, the results thus far (composition, nutrients, and microbiology) indicate that crossbreeding and diet affected certain meat quality traits (fat content and fatty acid profile) while not negatively impacting the basic composition or safety of the meat. Next, we present the findings on visual marbling and color, which are important quality attributes from a consumer standpoint.

3.5. Visual Marbling and Meat Color

The visual appearance of the meat differed noticeably between the purebred and crossbred lambs, consistent with the chemical fat results. Figure 1 and Figure 2 provide a direct comparison of marbling in the loin (longissimus lumborum) and leg (biceps femoris) muscles, respectively, for each group. Photographic images show that the purebred control lambs had very little visible marbling (virtually no intramuscular fat, with only subcutaneous fat around the edges of the cuts). In contrast, crossbred Group 1 lambs showed abundant fine striations of intramuscular fat evenly distributed throughout the loin muscle, and noticeable marbling even in the leg muscle. Crossbred Group 2 lambs had intermediate marbling: their loin had visible fat streaks, though less uniformly distributed and slightly thinner than those in Group 1, and their leg muscle displayed only sparse marbling, more closely resembling the leaner control leg. These observations from the photographs and visual scores indicate that while both crossbred lines increased IMF deposition, the line 1 cross (Group 1) was especially effective at depositing fat uniformly across different muscles, whereas the line 2 cross (Group 2) concentrated fat in certain areas (primarily the loin) more than others (the leg).
Despite the differences in marbling, all the meat samples had an appealing red color. There were some genotype effects on the instrumental color parameters (Table 6): for instance, Group 1 had a significantly lower L* value (darker meat) than the other groups (mean L* ~35.5 in Group 1 vs. ~45.0 in control; p < 0.05), and Group 1 also had a slightly lower chroma C* (less vivid red) compared to the control (p < 0.05). Group 2’s color parameters were intermediate (L* ~43.6, C* between the control and Group 1). Statistically, all three groups differed in L* (control > Group 2 > Group 1, p < 0.05 for each pair), indicating the purebred lambs had the brightest (lightest) muscle color and Group 1 the darkest. Interestingly, there were no significant differences in the redness (a) values * among the groups (p > 0.05). The a* value, which represents the intensity of red color, was virtually the same for the control, Group 1, and Group 2 (all around 12–13 units). Likewise, hue angle h was similar (around 34–36°) and did not differ significantly. This means that although Group 1 meat was darker (lower L*), it was not due to a lack of red hue but likely due to a higher concentration of muscle pigment (myoglobin) or other factors unrelated to pH (since pH was normal for all groups).
From a practical perspective, all lamb cuts presented a desirable color—a bright cherry-red typical of fresh lamb. The slightly darker appearance of Group 1’s meat could be perceived as richer by some consumers, and it did not indicate any quality defect (such as dark cutting meat, which is usually associated with high pH and pre-slaughter stress; here, the pH was normal). Group 2’s meat color closely resembled the control’s in both redness and brightness, suggesting that crossing did not compromise the visual attractiveness of the meat. In fact, Group 2’s crossbred meat exhibited a bright red hue and vividness comparable to the purebred meat, indicating that the crossbreeding regimen did not diminish consumer-valued appearance traits. Group 1’s darker tone is likely explained by its higher muscle pigment content, potentially due to greater muscle development, and possibly its fine marbling which can sometimes give a slightly opaque appearance. Notably, higher myoglobin in more muscular animals can darken meat [43], whereas higher intramuscular fat tends to lighten the perceived color by scattering light (as fat has a light color). Our results seem to reflect both phenomena: Group 1 might have had a higher myoglobin concentration dominating the color (resulting in darker meat), while Group 2 had a balance of added fat and pigment such that the meat maintained brightness.
Crucially, crossbreeding did not cause any pale or unattractive coloration; on the contrary, the crossbred meats were visually appealing and had plenty of marbling. This is an important practical point: producers can achieve improved marbling through crossbreeding without sacrificing the vibrant red color that signals freshness to consumers. The visual marbling scores aligned perfectly with the chemical IMF measurements, underscoring the reliability of simple marbling evaluation. Both assessment methods ranked the groups as Group 1 > Group 2 > control in marbling level. This agreement is consistent with findings by Guy et al. [44], who reported a very high correlation (r ≈ 0.99) between visual marbling scores and actual IMF content in lamb. Our observations also resonate with the authors of [45], who emphasized that visual appeal and color stability are critical for consumer acceptance and that moderate increases in IMF do not necessarily compromise color if managed properly.

4. Discussion

Crossbreeding Kazakh Finewool lambs with Suffolk sires under a high-energy diet significantly improved key meat quality traits without compromising other attributes. The crossbred lambs in our study showed roughly 30–40% higher intramuscular fat levels (on average, ~8–9% IMF in the loin) compared to purebred Finewool controls (~6.5% IMF). This substantial increase in marbling is beneficial because as IMF rises, meat tends to be juicier and more flavorful—fat contributes to flavor precursors and moisture retention during cooking. Although we did not conduct a sensory panel, it is well established that higher marbling generally enhances lamb palatability [46]. The pronounced jump in IMF achieved by introducing Suffolk genetics aligns with expectations from meat breed crossbreeding programs and is supported by recent findings on breed-specific IMF deposition, such as those in Tunisian breeds and Hu sheep [6,47,48]. Suffolk-sired lambs are predisposed to greater fat deposition in muscle, and similar outcomes have been noted in the literature; for example, Anderson et al. [49] found that crossbred lambs had higher IMF than pure breeds under comparable conditions. Similar improvements in carcass traits and IMF have been reported in other crossbreeding programs, for example in Landrace Hair × crossbred lambs supplemented with agro-byproducts [50]. Our results reinforce that incorporating a specialized meat breed can substantially boost marbling in the offspring—in this case yielding roughly a one-third increase in IMF, which is a meaningful improvement for eating quality.
Importantly, the crossbred lambs also exhibited a more favorable fatty acid profile in their intramuscular fat. Both crossbred groups had slightly lower proportions of saturated fatty acids and higher proportions of unsaturated fatty acids (MUFAs and PUFAs) relative to the purebred lambs. These shifts in fatty acid composition align with findings from high-energy diets in Tibetan sheep [47], and also with concentrate-to-forage feeding trials where PUFA and MUFA fractions improved under higher concentrate feeding [51]. However, not all these differences were statistically significant; in particular, the increase in PUFAs (especially in Group 2) was significant (p < 0.05), whereas the higher MUFAs in crossbreds was a positive trend that did not reach significance. Nonetheless, the direction of change—towards more MUFAs and PUFAs—is nutritionally desirable for consumers, as also demonstrated by Stanišić et al. [52], who found that pasture-fed lambs with added concentrates exhibited significantly increased n-3 PUFA content and more favorable n-6/n-3 ratios compared to conventional feeding. A greater unsaturated fat content in meat is often associated with healthier lipid intake for humans. This improvement in fatty acid composition, achieved via crossbreeding and diet, suggests that the meat from Suffolk-cross lambs could be marketed as having a healthier fat profile (with more oleic and linoleic acids) compared to meat from the pure local breed.
Another key finding is that these enhancements in fat content and composition were achieved without any detriment to meat appearance or safety. All groups had normal ultimate pH (~5.7–5.8) and high water activity, indicating that the intensive feeding and faster growth of crossbreds did not lead to any issues like dark cutting or excessive drip loss. The meat color remained excellent across groups: despite minor differences in lightness, all lamb meat was bright red and visually attractive. In fact, the Group 2 crossbred lambs combined high marbling with a bright red color very similar to the purebred controls, showing that the crossbreeding + diet strategy did not compromise the visual quality of the meat. This outcome is favorable, as maintaining an appealing red color is key for retail acceptance. Our results concur with observations by Faustman and Suman [43] that genetic and physiological factors (like myoglobin levels) can influence meat lightness, but in our case the higher IMF in crossbreds did not cause any unwanted paleness—if anything, it helped keep the meat looking “rich” but still red. In summary, using Suffolk genetics did not lead to any visual drawbacks; instead, by increasing marbling while retaining a healthy red color, the crossbred meat could be even more appealing in certain markets.
The visual marbling assessment further confirmed the superior intramuscular fat in crossbreds and provided insight into fat distribution patterns. We observed that the two crossbred lines differed slightly in how the fat was distributed: Group 1 (one Suffolk × Finewool lineage) had very fine, evenly distributed marbling throughout both loin and leg, whereas Group 2 (the other lineage) had high fat in the loin but much less in the leg. Consumers typically prefer fine, well-distributed marbling over large, uneven fat deposits; so the Group 1 crossbred might yield more consistently premium cuts. This kind of detail underscores that not all crossbreds are identical—different sire lines or genetic backgrounds can result in different marbling patterns, an aspect that could be explored further in breeding programs.
From a meat safety standpoint, all the meat met standard microbiological criteria. For ensuring authenticity of lamb meat products, advanced spectroscopic methods have also been shown to accurately detect adulteration with other species [53]. Total bacterial counts were low and did not differ between purebred and crossbred groups. This indicates that the higher fat content in crossbred lambs did not adversely affect microbial growth in the fresh meat, at least in the immediate post-slaughter period. The excellent hygiene during slaughter and the rapid chilling of carcasses were likely the main reasons for the low microbial counts observed in all groups. Because all samples had similar pH and AW in the normal range (and those factors were not different between genotypes), we attribute the microbiological safety primarily to proper sanitation and temperature control rather than any inherent difference caused by the diets or genetics. In other words, the crossbreeding and feeding regimen produced meat that was just as safe and shelf-stable as the purebred meat. Recent studies also confirm that feeding strategies play a key role in carcass quality and oxidative stability: high-energy diets improved flavor and juiciness in Tibetan sheep [47], while optimal forage-to-concentrate ratios enhanced tenderness and microbial balance [54]. This is an important assurance for producers and consumers: introducing a new breed and intensive feeding did not introduce any food safety risks. Past studies have noted that higher muscle vitamin E (α-tocopherol) and other antioxidants can prolong shelf life by slowing oxidation [44]; in our study, the crossbred meat’s elevated vitamin E might similarly help maintain quality during storage, complementing the hygienic processing to ensure a safe, long-lasting product.
The crossbred lambs also showed enhancements in certain micronutrients. In particular, vitamin E was ~40% higher in crossbred meat (especially Group 2) compared to the control. This is significant because muscle vitamin E is known to improve meat’s oxidative stability, meaning the meat is less prone to developing rancid odors or discoloration over time. The higher α-tocopherol content in the crossbreds’ meat could therefore translate to a longer shelf life and better color retention, which is a valuable trait for the industry. These findings are consistent with other observations that feeding systems can alter both oxidative stability and the visual color characteristics of lamb meat [55]. Additionally, the crossbreds had moderately higher vitamin A and zinc levels in their meat. Although these differences were modest, they do improve the nutritional profile of the lamb: more vitamin A contributes to the meat’s value as a source of this nutrient, and extra zinc can be a selling point given zinc’s role in human health (immune function, etc.). These micronutrient increases, together with the improved fatty acid profile, support the idea that the crossbred lamb meat can be considered a more “functional” or value-added product (i.e., richer in beneficial nutrients).
Overall, our findings demonstrate that introducing Suffolk genetics into a local Kazakh Finewool population, combined with a high-energy feeding program, is an effective strategy to produce lambs with superior meat quality. The improvements in intramuscular fat content, fatty acid composition, and certain vitamins were achieved without any negative impacts on meat leanness (protein content), appearance, or safety. This suggests a win–win scenario: producers can significantly enhance meat quality (marbling, flavor potential, nutritional value) through crossbreeding and specialized feeding, while still delivering a product that meets all the standard criteria for freshness and safety.
It is also worth considering some practical implications and future perspectives. The degree of improvement observed—roughly 2.5 percentage points more IMF in crossbreds, plus a shift toward unsaturated fat—is substantial in meat quality terms. If these crossbreeding practices were adopted widely, they could elevate the eating quality of lamb in Kazakhstan’s market, potentially allowing farmers to access premium prices for better-marbled, “healthier” lamb meat. On the other hand, our study did not evaluate growth performance or economic factors in detail. We noticed no differences in final live weights or average daily gains between the groups over just 30 days, but longer trials might reveal whether crossbreds grow faster or convert feed more efficiently. Those aspects will be critical for cost–benefit analysis. Additionally, consumer acceptance studies (tasting panels) would be valuable to confirm that the higher IMF indeed translates into a preferable eating experience.
In conclusion, this work provides strong evidence that meat breed crossbreeding, combined with intensive feeding, can greatly improve lamb meat quality in terms of marbling and nutritional value, without sacrificing other quality attributes. Our results support the broader adoption of Suffolk × Finewool crossbreeding programs in Kazakhstan’s sheep industry as a means to meet the evolving demands of modern consumers for high-quality, flavorful, and nutritious red meat. Future research should focus on optimizing the crossbreeding strategy (such as selecting the best-performing F1 lines or evaluating F2 generations), as well as incorporating modern non-destructive analytical tools [53] and exploring pasture-integrated feeding strategies to enhance the nutritional profile [54]. Nonetheless, the present findings clearly show the potential benefits of integrating specialized meat breed genetics into local flocks for producing premium lamb that can satisfy both domestic and international market expectations.

5. Conclusions

Crossbreeding the local Kazakh Finewool sheep with a Suffolk meat breed and finishing the lambs on a high-energy grain diet proved to be a highly effective strategy to enhance lamb meat quality. The Suffolk crossbred lambs had substantially higher intramuscular fat (marbling) in the loin muscle and a more unsaturated fatty acid profile compared to the purebred Finewool lambs. These improvements in fat content and composition were achieved without any negative effects on other quality parameters: the crossbred meat maintained a high protein content, normal pH, and water-holding capacity, and exhibited an attractive bright red color similar to the purebred meat. All meat from both crossbred and purebred groups met microbiological safety standards. Additionally, the crossbred lambs’ meat contained slightly elevated levels of certain beneficial nutrients (such as vitamin A, vitamin E, and zinc) relative to the purebred meat [45,53].
Overall, our findings highlight the value of combining specialized meat breed genetics with intensive feeding regimes in lamb production [55,56]. By introducing Suffolk genetics into Kazakh Finewool sheep and providing a high-energy diet, producers can obtain lamb carcasses with superior marbling and improved meat characteristics while still ensuring the product’s safety and visual appeal. This study provides a scientific basis to support the broader adoption of Suffolk × Finewool crossbreeding in Kazakhstan’s sheep industry, as a means to meet growing consumer demand for high-quality, nutrient-enriched lamb. We recommend that future work include larger-scale trials with sensory evaluations and economic analyses to further validate and optimize this crossbreeding approach. Nevertheless, the current results clearly demonstrate the significant quality gains achievable through crossbreeding and specialized fattening—a promising strategy for producing premium lamb that can enhance competitiveness and profitability for local producers.

Author Contributions

U.C. conceived and designed the study; A.A. performed the experiments; Z.K. analyzed the data; G.K. provided critical reagents and analytical tools; Z.K. wrote the manuscript. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Ministry of Agriculture of the Republic of Kazakhstan grant number BR24892775.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Acknowledgments

The presented research was carried out within the framework of the program “Developing technology for deep processing of agricultural raw materials to ensure high-quality, safe food production”.

Conflicts of Interest

Authors Gulmira Kenenbay, Urishbay Chomanov, Zhanayna Kramsakova and Arailym Abilda were employed by LLP “Kazakh Research Institute of Processing and Food Industry”. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. LLP “Kazakh Research Institute of Processing and Food Industry” had no role in the design of the study, the collection, analysis, or interpretation of data, the writing of the manuscript, or the decision to publish the results.

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Figure 1. Visual marbling in dorsal muscle (longissimus lumborum) across genotype groups.
Figure 1. Visual marbling in dorsal muscle (longissimus lumborum) across genotype groups.
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Figure 2. Visual marbling in femoral muscle (biceps femoris) across genotype groups.
Figure 2. Visual marbling in femoral muscle (biceps femoris) across genotype groups.
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Table 1. Daily composition of the compound feed per lamb in the two fattening phases (as-fed basis, grams). Each lamb also received 2000 g/day of alfalfa hay in both phases.
Table 1. Daily composition of the compound feed per lamb in the two fattening phases (as-fed basis, grams). Each lamb also received 2000 g/day of alfalfa hay in both phases.
ComponentPhase I (g)Phase II (g)
Barley270150
Corn150350
Alfalfa hay20002000
Sunflower meal10001000
Yeasts100100
Corn gluten100100
Fish meal1010
Meat and bone meal7070
Phase I: Days 1–15 of fattening (higher protein, moderate energy). Phase II: Days 16–30 (higher energy density via increased corn). The compound feed was pelleted; nutritional composition was ~16% crude protein, ~11 MJ/kg metabolizable energy, with adequate fiber and micronutrients for lamb growth.
Table 2. Chemical and physicochemical properties of longissimus lumborum (loin) muscle from lambs of each genotype (mean ± SD, n = 12 per group). Different superscript letters within a row indicate significant differences between groups (p < 0.05).
Table 2. Chemical and physicochemical properties of longissimus lumborum (loin) muscle from lambs of each genotype (mean ± SD, n = 12 per group). Different superscript letters within a row indicate significant differences between groups (p < 0.05).
IndicatorControl
(Purebred Finewool)		Group 1
(Suffolk × Finewool)		Group 2
(Suffolk × Finewool)
Moisture, %74.5 ± 0.572.0 ± 0.470.5 ± 0.6
Crude protein, %18.0 ± 0.317.8 ± 0.417.5 ± 0.4
Intramuscular fat, %6.5 ± 0.4 b8.0 ± 0.5 a9.0 ± 0.6 a
Ash, %1.1 ± 0.11.2 ± 0.11.3 ± 0.1
pH5.70 ± 0.025.75 ± 0.025.80 ± 0.01
Water activity (Aw)0.985 ± 0.0010.986 ± 0.0010.987 ± 0.001
Note: All lambs were fed the same diet; differences reflect genotype effects. Within a row, means with different superscript letters differ significantly (Tukey’s HSD, p < 0.05). No letters for protein, ash, pH, or Aw indicate no significant group effect (p > 0.05).
Table 3. Fatty acid composition of intramuscular fat (longissimus muscle) in lambs of each genotype (mean ± SD, expressed as % of total fatty acids). ΣSFA: total saturated fatty acids; ΣMUFA: total monounsaturated fatty acids; ΣPUFA: total polyunsaturated fatty acids. Different letters within a row indicate a significant difference (p < 0.05).
Table 3. Fatty acid composition of intramuscular fat (longissimus muscle) in lambs of each genotype (mean ± SD, expressed as % of total fatty acids). ΣSFA: total saturated fatty acids; ΣMUFA: total monounsaturated fatty acids; ΣPUFA: total polyunsaturated fatty acids. Different letters within a row indicate a significant difference (p < 0.05).
IndicatorControlGroup 1Group 2
ΣSFA (%)39.5 ± 1.137.2 ± 1.035.0 ± 1.2
ΣMUFA (%)38.7 ± 1.039.0 ± 1.141.5 ± 1.3
ΣPUFA (%)21.8 ± 1.2 b22.8 ± 1.3 ab23.5 ± 1.2 a
Within each row, values with different superscripts differ significantly (p < 0.05). No superscript letters for SFA or MUFA indicate no significant genotype effect for those fractions.
Table 4. Vitamin and mineral composition of lamb loin meat (per 100 g of raw muscle). Values are mean ± SD. Vitamin A and B12 are in micrograms (μg); vitamin E and minerals are in milligrams (mg). Different letters indicate significant differences between groups for that nutrient (p < 0.05).
Table 4. Vitamin and mineral composition of lamb loin meat (per 100 g of raw muscle). Values are mean ± SD. Vitamin A and B12 are in micrograms (μg); vitamin E and minerals are in milligrams (mg). Different letters indicate significant differences between groups for that nutrient (p < 0.05).
NutrientControlGroup 1Group 2
Vitamin A (μg)25 ± 3 b30 ± 4 ab35 ± 5 a
Vitamin E (mg)1.0 ± 0.1 b1.2 ± 0.1 ab1.4 ± 0.1 a
Vitamin B12 (μg)0.50 ± 0.050.55 ± 0.060.60 ± 0.05
Iron (mg)2.0 ± 0.22.1 ± 0.22.2 ± 0.2
Zinc (mg)3.0 ± 0.2 b3.1 ± 0.2 ab3.3 ± 0.3 a
Calcium (mg)15 ± 217 ± 218 ± 3
Within each row, values sharing no common superscript letter differ significantly (p < 0.05). Vitamin A, vitamin E, and Zn were significantly higher in Group 2 vs. control. Vitamin B12, Fe, and Ca showed no significant group differences.
Table 5. Microbiological quality indicators of lamb meat (longissimus muscle) from each group. Values are mean ± SD. TMB: total mesophilic aerobic bacteria (log10 CFU/g); Enterobacteria: Enterobacteriaceae count (log10 CFU/g); Pathogens: presence/absence of Salmonella spp. and Staphylococcus aureus in 25 g (for Salmonella) or 0.1 g (for S. aureus).
Table 5. Microbiological quality indicators of lamb meat (longissimus muscle) from each group. Values are mean ± SD. TMB: total mesophilic aerobic bacteria (log10 CFU/g); Enterobacteria: Enterobacteriaceae count (log10 CFU/g); Pathogens: presence/absence of Salmonella spp. and Staphylococcus aureus in 25 g (for Salmonella) or 0.1 g (for S. aureus).
Microbiological ParameterControlGroup 1Group 2
TMB (log10 CFU/g)3.30 ± 0.103.40 ± 0.113.32 ± 0.12
Enterobacteriaceae (log10 CFU/g)1.20 ± 0.101.10 ± 0.101.05 ± 0.10
Salmonella (25 g sample)not detectednot detectednot detected
Staph. aureus (25 g sample)not detectednot detectednot detected
No significant differences were observed between groups for TMB or Enterobacteriaceae counts (p > 0.05). All values are within acceptable ranges for fresh lamb meat. Pathogens (Salmonella spp. and Staphylococcus aureus) were absent in all samples.
Table 6. Instrumental color parameters (CIE L*, a*, b*, chroma C*, and hue angle h°) of lamb meat for each genotype, measured on the longissimus lumborum muscle. Values are means of 12 observations per group. Different letters within a column indicate significant differences between groups for that color coordinate (p < 0.05). A descriptive visual color is also provided for reference.
Table 6. Instrumental color parameters (CIE L*, a*, b*, chroma C*, and hue angle h°) of lamb meat for each genotype, measured on the longissimus lumborum muscle. Values are means of 12 observations per group. Different letters within a column indicate significant differences between groups for that color coordinate (p < 0.05). A descriptive visual color is also provided for reference.
Color ParameterControlGroup 1Group 2
L*
(lightness)		50.59 a35.47 c43.61 b
a*
(redness)		26.9121.4025.27
b*
(yellowness)		15.6914.0014.42
C*
(chroma)		31.15 a25.57 b29.09 a
h°
(hue angle)		30.2533.1929.71
Approx. Visual ColorBright redReddish-brownRich red (moderate)
Within each column, means with different superscripts differ significantly (p < 0.05). No letters in the a*, b*, or h° columns indicate no significant genotype effect on those parameters. Visual color descriptors are provided as a qualitative aid.
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MDPI and ACS Style

Kenenbay, G.; Chomanov, U.; Kramsakova, Z.; Abilda, A. Marbling and Meat Quality of Kazakh Finewool Purebred and Suffolk × Finewool Crossbred Sheep on an Intensive Fattening Diet. Processes 2025, 13, 2874. https://doi.org/10.3390/pr13092874

AMA Style

Kenenbay G, Chomanov U, Kramsakova Z, Abilda A. Marbling and Meat Quality of Kazakh Finewool Purebred and Suffolk × Finewool Crossbred Sheep on an Intensive Fattening Diet. Processes. 2025; 13(9):2874. https://doi.org/10.3390/pr13092874

Chicago/Turabian Style

Kenenbay, Gulmira, Urishbay Chomanov, Zhanayna Kramsakova, and Arailym Abilda. 2025. "Marbling and Meat Quality of Kazakh Finewool Purebred and Suffolk × Finewool Crossbred Sheep on an Intensive Fattening Diet" Processes 13, no. 9: 2874. https://doi.org/10.3390/pr13092874

APA Style

Kenenbay, G., Chomanov, U., Kramsakova, Z., & Abilda, A. (2025). Marbling and Meat Quality of Kazakh Finewool Purebred and Suffolk × Finewool Crossbred Sheep on an Intensive Fattening Diet. Processes, 13(9), 2874. https://doi.org/10.3390/pr13092874

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