Meat Quality and Mineral Composition of the Sheep Semimembranosus Muscle Under a Feeding Strategy Including Parkia platycephala Pod and Whole Corn Grain

Simple Summary

Sheep farmers often face high feeding costs, especially when they rely on ingredients such as hay and corn. Therefore, identifying local plant resources that can be used as safe and nutritious alternative feedstuffs is essential. In this study, we evaluated whether the pod of the native tree Parkia platycephala, which produces large amounts of edible pods, could replace traditional dietary ingredients for sheep without negatively affecting meat quality. We compared animals fed a conventional diet with those fed a diet containing Parkia platycephala pod and whole corn grain, and subsequently analyzed the Semimembranosus muscle, a commercially important cut from the hind leg. The results showed that the evaluated feeding strategy did not significantly affect important meat quality traits, including color, tenderness, moisture, fat, protein, and mineral composition. These findings indicate that Parkia platycephala pod may be used as a safe alternative feed resource for sheep under the present experimental conditions, particularly in regions where this species is naturally abundant. The use of local feed resources such as Parkia platycephala pod may contribute to reducing dependence on conventional feed ingredients and support more sustainable sheep production systems.

Abstract

Parkia platycephala pod (PP) is a native feed resource with good nutritional value that can be included in sheep diets as a potential alternative ingredient without impairing the meat quality. Thus, the aim of this study was to evaluate the effect of two feeding strategies differing in forage source and corn processing form, including the use of Parkia platycephala pod and whole corn grain, on the physicochemical characteristics, proximate composition, and mineral profile of sheep meat. For this, the Semimembranosus muscle from the hind legs of twelve castrated male Dorper × Santa Inês sheep was evaluated. The animals were fed two diets: diet 1—without Parkia platycephala pod (30% Tifton hay + 20% ground corn)—and diet 2—with Parkia platycephala pod (30% Parkia platycephala pod + 0% ground corn). A completely randomized design with two treatments and six replicates was used. There was no effect of diet on the physicochemical characteristics, proximate composition and mineral profile of the Semimembranosus muscle (p > 0.05). Therefore, the inclusion of Parkia platycephala pod in sheep diets is recommended, as it does not alter meat quality.

1. Introduction

In animal production, feed represents the highest production cost, a factor directly related to the availability of feed resources in each region, making it a determining component of the viability of production systems. Consequently, new trends in ruminant feedlot systems aim to develop production models that are increasingly competitive, sustainable, and economically viable. However, the high cost of inputs such as corn and soybean meal, which are widely used in animal feeding, combined with the need to purchase conserved forages, especially hay, increases production costs [1].

Tifton-85 (Cynodon spp.) hay is a forage widely used in diets for small ruminants [2]; however, its use may increase diet formulation costs due to the labor required for its production or acquisition. In addition, the productivity and utilization of Tifton-85 are associated with management practices involving intensive use of inputs such as chemical fertilization and supplemental irrigation [3]. Inadequate pasture management may also reduce its nutritional value, negatively affecting animal performance. Therefore, recent studies have focused on replacing this forage with alternative feedstuffs in order to identify locally available feed resources capable of substituting conventional ingredients without compromising the nutritional quality of the diet [2,4,5].

The Brazilian Cerrado hosts a wide variety of rare and endemic plant species with strong potential for use in ruminant feeding. One important native forage species and natural feed resource for sheep is Parkia platycephala Benth. [6]. This arboreal legume, belonging to the subfamily Mimosoideae, produces approximately 1208 kg/ha of pods annually [7]. When mature, these pods are considered an excellent supplemental feed resource for ruminants during the dry season [8].

Parkia platycephala pods present adequate crude protein levels (11.18% of dry matter) and contain phenolic compounds, including tannins (10.79% of dry matter) [7], which may influence ruminal fermentation and meat quality. The use of alternative feedstuffs capable of meeting the nutritional requirements of sheep diets, such as Parkia platycephala pods, has proven effective as a substitute for conventional ingredients such as corn. A previous study conducted by Gomes et al. [9] demonstrated that Parkia platycephala pods can replace 100% of ground corn in diets for small ruminants while maintaining similar intake, performance, and carcass yield.

Meat is widely recognized as a source of high-biological-value protein, containing all essential amino acids in adequate proportions for human nutrition [10]. The growing demand for healthier diets has stimulated an increasing number of studies aimed at improving the nutritional characteristics of sheep meat while preserving its organoleptic properties [11,12,13]. Lima et al. [14], when evaluating different levels of ground Parkia platycephala pod as a substitute for corn in sheep diets and assessing its effects on the nutritional quality of the loin cut, recommended the use of this feedstuff as an alternative ingredient in sheep feeding, since it promoted physicochemical and proximate composition characteristics similar to those obtained with corn grain.

Previous studies conducted by our research group demonstrated that Parkia platycephala pod can replace conventional feed ingredients such as ground corn without impairing intake, digestibility, ruminal fermentation, carcass yield, or meat quality in sheep [9,14,15,16]. These findings support the potential applicability of this native feed resource in sheep production systems.

However, no studies have evaluated the effects of Parkia platycephala pod on the nutritional characteristics of the Semimembranosus muscle. Therefore, further research is needed to generate information that can be shared with the scientific community, producers, and society regarding meat quality in sheep fed diets containing Parkia platycephala pod. Research efforts have increasingly focused on reducing meat fat content while maintaining important quality traits such as flavor, aroma, texture, and appearance. However, reductions in fat content may negatively affect water-holding capacity and increase cooking losses [17]. We hypothesized that the feeding strategy including Parkia platycephala pod and whole corn grain in diets for feedlot sheep in the Cerrado region could replace Tifton-85 hay and ground corn without impairing the nutritional quality of the meat.

Thus, the aim of this study was to evaluate the effect of two feeding strategies differing in forage source and corn processing form, including the use of Parkia platycephala pod and whole corn grain, on the physicochemical characteristics, proximate composition, and mineral profile of sheep meat.

2. Materials and Methods

2.1. Experimental Site

The experiment was conducted at the Laboratory of Animal-Origin Products (LAPOA) of the Chapadinha Science Center at the Federal University of Maranhão (CCCh/UFMA), located in Chapadinha, Maranhão, Brazil (03°4′33″ S latitude and 43°21′21″ W longitude). The region’s climate is classified as hot tropical Aw according to Köppen [18], with an average annual precipitation of 1670 mm and maximum and minimum temperatures of 38 and 22 °C, respectively.

The experimental period lasted 60 days, with the first 10 days allocated for animal adaptation to the facilities, diets, and management, and the remaining 50 days for data collection.

2.2. Samples, Animals, Treatments, and Experimental Diets

The Semimembranosus muscle from the left hind leg of 12 castrated male Dorper × Santa Inês sheep (5 months of age and initial body weight of 16 ± 2.0 kg) was evaluated. The animals were fed diets formulated according to NRC [19] recommendations, with a forage-to-concentrate ratio of 30:70, on a dry matter basis, as follows: Diet 1—without Parkia platycephala pod (30% Tifton hay + 20% ground corn)—and Diet 2—with Parkia platycephala pod (30% Parkia platycephala pod + 0% ground corn) (

Table 1. Ingredients and composition of the experimental diets offered to the sheep.

Items (g/kg of Dry Matter)	Treatments
	Diet 1	Diet 2
Tifton-85 hay	30	0
Parkia platycephala pod	0	30
Whole corn grain	0	20
Ground corn	20	0
Soybean meal	16.7	14.5
Wheat bran	31	33.2
Mineral salt	2	2
Limestone	0.3	0.3
Chemical composition (g/kg of dry matter)
Dry matter	852.8	857.8
Ash	55.3	41.2
Organic matter	944.7	958.8
Crude protein	161.4	157.8
Ether extract	50.4	55.6
Neutral detergent fiber	378.8	199.9
Total carbohydrates	732.9	745.4
Non-fibrous carbohydrates	354.1	545.5
Metabolizable energy (Mcal/kg)	2.81	3.03
Total tannins **	-	3.15
Condensed tannins ***	-	0.48

Diet 1—without Parkia platycephala pod (30% Tifton hay + 20% ground corn), and Diet 2—with Parkia platycephala pod (30% Parkia platycephala pod + 0% ground corn); Composition of the mineral supplement per kilogram of product: Sodium, 147 g; Calcium, 120 g; Phosphorus, 87 g; Sulfur, 18 g; Zinc, 3800 mg; Iron, 1800 mg; Manganese, 1300 mg; Fluoride, 870 mg; Copper, 590 mg; Molybdenum, 300 mg; Iodine, 80 mg; Cobalt, 40 mg; Chromium, 20 mg; Selenium, 15 mg; ** tannic acid equivalent; *** leukocyanidin equivalent.

). The dietary treatments were intentionally formulated to represent two practical feeding strategies for sheep in confinement, following previous studies conducted by this research group [9,14,16]. All concentrate ingredients were ground prior to mixing, except for the whole corn grain included in the Parkia platycephala pod diet, which was intentionally maintained unprocessed in order to reduce feed processing requirements and simulate practical feedlot feeding conditions for lambs.

In the treatment containing Parkia platycephala pods, whole corn kernels were used instead of ground corn to maintain the dietary energy supply, reducing feed processing needs and increasing the practical applicability of the feeding strategy under production conditions.

A completely randomized design was adopted, with two treatments (diets) and six replicates. The diets were offered as a total mixed ration twice daily, at 08:00 h and 16:00 h. The amount of feed offered was adjusted daily to allow for 10% refusals, ensuring ad libitum intake for the sheep. During the experimental period, the animals presented average dry matter intake and average daily gain (in g/day) of 1107.2 and 200 (Diet 1) and 940.3 and 195 (Diet 2), respectively.

2.3. Slaughter Procedures

The animals were slaughtered after 60 days of the experimental period. The animals were slaughtered at an average body weight (in kg) of 30.16 (Diet 1) and 29.86 (Diet 2). Slaughter was performed in accordance with the Brazilian regulations for the industrial and sanitary inspection of products of animal origin [20]. All procedures followed the guidelines established by the Animal Ethics Committee (protocol no. 23115.005618/2023-79, approved on 14 March 2023).

After bleeding, skinning, and evisceration, the carcasses were chilled for 24 h at 4 ± 1 °C. The left legs were deboned and trimmed, and the Semimembranosus muscle was collected, identified according to treatment, wrapped in aluminum foil, and stored frozen (−20 °C) until laboratory analyses.

2.4. Laboratory Analyses

2.4.1. pH, Color, and Water-Holding Capacity

The pH was measured 24 h post-mortem. Meat pH was measured in the geometric center of the samples using a portable digital pH meter (TESTO-205, Testo SE & Co. KGaA, Campinas, SP, Brazil), previously calibrated with standard buffer solutions (pH 4.00 and 7.00).

Meat color was evaluated using a chromameter (Model Minolta CR-400, Minolta Co., Osaka, Japan), featuring an 8 mm aperture and a 10° standard observer angle, operating in the CIELAB system. The light source employed was a pulsed xenon lamp, and the aperture had a glass cover. Measurements were conducted under illuminant D65, calibrated with a white standard tile before each measurement. Prior to color measurement, meat samples were exposed to air for 30 min to allow blooming and oxygenation of myoglobin, ensuring stabilization of surface color and standardization of instrumental measurements, as recommended by AMSA [21] guidelines. Coordinates L* (lightness), a* (redness), and b* (yellowness) were taken at three surface points [22]. Chroma (c*) and hue angle (h°) were calculated according to Calnan et al. [23].

Water-holding capacity (WHC, %) was based on the percentage of free water in the meat. A 0.5 g sample was placed on filter paper (10 × 10 cm; Whatman No. 1) positioned between two acrylic plates. WHC was calculated as the difference between the sample weight before and after the application of a 5 kg mechanical force for 5 min, according to the method described by Honikel and Hamm [24]:

$$\begin{array}{ll}\mathrm{W}\mathrm{H}\mathrm{C}(\%)=& \left[\right(\mathrm{i}\mathrm{n}\mathrm{i}\mathrm{t}\mathrm{i}\mathrm{a}\mathrm{l} \mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t} \mathrm{o}\mathrm{f} \mathrm{t}\mathrm{h}\mathrm{e} \mathrm{m}\mathrm{e}\mathrm{a}\mathrm{t}\\ & -\mathrm{f}\mathrm{i}\mathrm{n}\mathrm{a}\mathrm{l} \mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t} \mathrm{o}\mathrm{f} \mathrm{t}\mathrm{h}\mathrm{e} \mathrm{m}\mathrm{e}\mathrm{a}\mathrm{t}/\mathrm{i}\mathrm{n}\mathrm{i}\mathrm{t}\mathrm{i}\mathrm{a}\mathrm{l} \mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t} \mathrm{o}\mathrm{f} \mathrm{t}\mathrm{h}\mathrm{e} \mathrm{m}\mathrm{e}\mathrm{a}\mathrm{t}\left)\right]\times 100\end{array}$$

2.4.2. Cooking Loss and Shear Force

Cooking loss (CL, %) was determined using standardized meat samples (1.5 cm thick; 3.0 cm long; 2.5 cm wide). The samples were thawed under refrigeration (8 °C; 12 h), according to AMSA [21] recommendations. After thawing, the samples were weighed and cooked on a preheated electric grill (CE053, Multilaser, São Paulo, SP, Brazil) at 170 °C. Cooking was terminated when the internal temperature reached 72 °C, as monitored using a type K thermocouple (HI935005, Hanna, Póvoa de Varzim, Portugal) connected to a digital reader. After cooling to room temperature, the samples were reweighed, and cooking loss (CL) was calculated according to AMSA [21].

The same cooked samples were used to evaluate shear force (SF). Two cores were removed parallel to the muscle fibers using a 1.27 cm coring device [21]. Due to the muscle size of sheep, the number of cores was reduced from that suggested by Holman et al. [25]. Shear force was measured using a Texture Analyzer (TX-TX2, Mecmesin, Sterling, VA, USA) equipped with a Warner–Bratzler blade, a 25-kgf load cell, and a crosshead speed of 20 cm/min.

2.4.3. Proximate Composition

Samples were thawed under refrigeration (8 °C for 12 h) and ground using a food processor (Mallory Oggi+, Rio de Janeiro, RJ, Brazil). Moisture (Method 950.46), ash (Method 920.153), and protein (Method 984.13) were determined according to AOAC [26]. Lipid content was determined following the Bligh and Dyer [27] method.

2.4.4. Mineral Profile

The contents of N (nitrogen), P (phosphorus), K (potassium), Ca (calcium), Mg (magnesium), S (sulfur), Cu (copper), Fe (iron), Zn (zinc), and Na (sodium) were determined according to the methodology described by Araújo et al. [28].

Nitrogen (N) content was determined according to the Kjeldahl method following sulfuric acid wet digestion, ammonia distillation, and acid titration. Phosphorus (P) and potassium (K) were extracted using the Mehlich⁻¹ solution. Phosphorus concentration was quantified by UV–Vis spectrophotometry (Mettler-Toledo Ind. e Com. Ltda, Barueri, Brazil) using the molybdenum blue method, whereas potassium concentration was determined by flame photometry. Calcium (Ca) and magnesium (Mg) were extracted with 1.0 mol L⁻¹ KCl solution and quantified by flame atomic absorption spectrophotometry (Agilent, 240FSAA, Santa Clara, California, United States). Sulfur (S) was extracted using monocalcium phosphate solution in acetic acid and determined by turbidimetry based on barium sulfate (BaSO₄) formation.

Iron (Fe), zinc (Zn), copper (Cu), and sodium (Na) concentrations were determined by flame atomic absorption spectrophotometry (Agilent, 240FSAA, Santa Clara, California, United States) after wet acid digestion of the samples. Approximately 0.5 g of homogenized meat sample was weighed and digested with concentrated nitric acid (HNO₃) and hydrogen peroxide (H₂O₂) until complete mineralization. After digestion, the extracts were filtered and diluted with deionized water. Mineral concentrations were quantified using a flame atomic absorption spectrophotometer equipped with element-specific hollow cathode lamps and external calibration curves prepared from certified standard solutions. Iron, zinc, copper, and sodium concentrations were measured at analytical wavelengths of 248.3, 213.9, 324.8, and 589.0 nm, respectively.

2.5. Statistical Analysis

Data were tested for residual normality (Shapiro–Wilk test) and homogeneity of variances (Levene’s test). Once assumptions were met, data were subjected to analysis of variance (ANOVA) using the Statistical Analysis System (SAS University Edition). Means were compared using Tukey’s test at a 5% significance level.

3. Results and Discussion

The results obtained for the physicochemical characterization of the Semimembranosus muscle are presented in

Table 2. Physicochemical characteristics of the Semimembranosus muscle of sheep fed diets with and without Parkia platycephala pod.

Items	Treatments		SEM	p-Value
	Diet 1	Diet 2
pH	5.54	5.56	0.012	0.105
Lightness (L*)	42.76	43.54	0.840	0.514
Redness (a*)	9.97	10.04	0.390	0.899
Yellowness (b*)	4.77	5.07	0.346	0.542
Chroma (c*)	11.09	11.45	0.339	0.463
Hue angle (h°)	0.44	0.48	0.036	0.499
Water-holding capacity (%)	64.97	66.03	1.361	0.589
Cooking loss (%)	25.99	27.67	1.220	0.340
Shear force (N)	23.50	25.31	0.803	0.115

Diet 1—without Parkia platycephala pod (30% Tifton hay + 20% ground corn), and Diet 2—with Parkia platycephala pod (30% Parkia platycephala pod + 0% ground corn); SEM = Standard error of the mean; p-value = Probability value; Mean values followed by different letters in the row differ statistically according to Tukey’s test at the 5% probability level.

. There was no effect of the diets on the evaluated physicochemical traits (p > 0.05), with mean values of 5.55 for pH, 43.15 for L*, 10.00 for a*, 4.92 for b*, 11.27 for c*, 0.46 for h°, 65.50% for WHC, 26.83% for CL, and 24.41 N for SF (Table 2).

The absence of dietary effects on pH, color parameters (L*, a*, b*, c*, and h°), water-holding capacity, cooking loss, and shear force suggests that the evaluated feeding strategy did not alter the main post-mortem biochemical processes responsible for meat quality. In the present study, meat pH remained within the normal range for sheep meat (5.5–5.8; [14]), indicating adequate post-mortem glycolysis and proper conversion of muscle into meat [29]. This is biologically relevant because the decline in pH directly affects myofibrillar protein denaturation, water retention, light scattering, color development, and tenderness [30,31].

Since the inclusion of the pod of Parkia platycephala resulted in physicochemical characteristics similar to those observed for Tifton hay-85, it can be inferred that its use in sheep feeding is beneficial, as it did not negatively affect the main quality attributes considered by consumers during meat preparation and consumption. Furthermore, the mean lightness (L*) values above 34 indicate a desirable bright appearance for lamb meat, whereas shear force values below 30 N characterize the meat as extremely tender and highly acceptable to consumers [32,33]. Tenderness is considered one of the most important sensory attributes affecting consumer perception and purchasing decisions, and the maintenance of low shear force values indicates that the dietary strategy did not impair myofibrillar integrity or connective tissue characteristics [34]. Therefore, under the present experimental conditions, the inclusion of Parkia platycephala pod combined with whole corn grain preserved the functional and sensory-related quality traits of the Semimembranosus muscle.

It is important to highlight that the dietary treatment involved not only the replacement of Tifton-85 hay with Parkia platycephala pods, but also the substitution of ground corn with whole corn grain. The physical form of corn may influence ruminal starch degradation kinetics, nutrient digestibility, and ruminal fermentation patterns, since ground corn generally presents faster fermentation and greater starch availability than whole corn grain [35]. However, the similar physicochemical responses observed in the present study may be associated with the nutritional balance of the experimental diets, as both feeding strategies promoted similar final body weight and average daily gain, indicating an adequate nutrient supply to sustain comparable muscle growth and post-mortem metabolism.

Studies with feedlot sheep have demonstrated that diets based on whole corn grain can maintain adequate nutrient digestibility, ruminal fermentation, feed efficiency, and animal performance, while also reducing feed processing requirements [35]. Similarly, studies by Gallo et al. [36] reported that the use of whole corn grain did not impair productive performance, carcass traits, or meat quality characteristics in feedlot sheep. Therefore, the use of whole corn grain associated with Parkia platycephala pods in the present study likely maintained sufficient dietary energy availability without causing detectable changes in meat quality characteristics. These results corroborate the findings of the present study, in which no changes were observed in the physicochemical characteristics of the Semimembranosus muscle.

Additionally, Gomes et al. [9] and Lima et al. [14] demonstrated that Parkia platycephala pods can replace ground corn in small ruminant diets without impairing intake, digestibility, performance, ruminal fermentation, carcass yield, or meat quality. Therefore, the adoption of whole corn grain in the present study aimed to maintain the dietary energy contribution while simultaneously reducing operational costs and increasing the practical applicability of the feeding strategy in sheep production systems. Thus, although the physical form of corn may modify certain aspects of ruminal fermentation, the obtained results indicate that the combined use of Parkia platycephala pods and whole corn grain did not impair meat quality, suggesting that the observed effects reflect the overall nutritional balance of the experimental diets rather than exclusively the processing method of the corn.

The results for the proximate composition of the Semimembranosus muscle are presented in

Table 3. Proximate composition of the Semimembranosus muscle of sheep fed diets containing Parkia platycephala pod.

Items (%)	Treatments		SEM	p-Value
	Diet 1	Diet 2
Moisture	71.42	71.12	0.020	0.375
Ash	1.12	1.14	0.012	0.136
Protein	21.91	22.87	0.130	0.149
Lipids	5.54	5.15	0.031	0.316

Diet 1—without Parkia platycephala pod (30% Tifton hay + 20% ground corn), and Diet 2—with Parkia platycephala pod (30% Parkia platycephala pod + 0% ground corn); SEM = Standard error of the mean; p-value = Probability value.

. There was no dietary effect on any of the evaluated traits (p > 0.05), with mean values of 71.27, 1.13, 22.39, and 5.34%, respectively, for moisture, ash, protein, and lipids (Table 3).

Lima et al. [14] reported that sheep meat has a chemical composition of 75.00% moisture, 19.00% protein, 4.00% fat, and 1% ash. These values are similar to those obtained in the present study. However, those authors evaluated the Longissimus lumborum muscle of sheep fed diets with different levels of Parkia platycephala pod replacing corn. Thus, in the Semimembranosus muscle, a slight reduction in moisture content and an increase in protein and lipid levels were observed compared with the findings of Lima et al. [14].

Oliveira et al. [37] reported that the chemical composition of the Semimembranosus muscle in sheep may vary according to diet, muscle type, slaughter weight, physiological stage, and energy–protein balance. In the present study, the animals presented similar slaughter weights and were subjected to the same finishing period, which likely contributed to the comparable deposition of protein and lipids in the Semimembranosus muscle. Oliveira et al. [37] also stated that lean meat should contain up to 5% fat, which is consistent with the present study. In addition, they indicated that protein contents above 21% in the Semimembranosus muscle are considered beneficial, since meat is an essential source of high-quality protein for human nutrition.

Although the present study did not evaluate the fatty acid profile of the meat, the hypothesis regarding possible improvements in meat nutritional quality was supported by previous evidence demonstrating that tannin-containing feedstuffs may influence ruminal lipid metabolism and fatty acid biohydrogenation [14,38]. In this context, modifications in the proportions of saturated and unsaturated fatty acids may occur even in the absence of changes in total intramuscular lipid concentration. Lima et al. [14], when evaluating the inclusion of Parkia platycephala pod in sheep diets, reported alterations in the fatty acid composition of the Longissimus lumborum muscle, indicating that this feedstuff may influence the nutritional quality of sheep meat lipids. Similarly, possible qualitative modifications in fatty acid composition cannot be ruled out, even though total lipid concentration was not altered in the present study. Furthermore, total lipid concentration alone is insufficient to fully characterize the nutritional quality of meat lipids, since changes in fatty acid profile may occur independently of total fat deposition. Therefore, further studies evaluating detailed fatty acid profiles are necessary to better understand the effects of Parkia platycephala pod on the lipid quality of the Semimembranosus muscle.

The mineral profile of the evaluated meat is presented in

Table 4. Mineral profile of the Semimembranosus muscle of sheep fed diets containing Parkia platycephala pod.

Items (mg/100 g)	Treatments		SEM	p-Value
	Diet 1	Diet 2
N	350.5	382.0	0.15	0.149
P	10.40	12.76	0.14	0.246
K	87.91	102.08	0.496	0.056
Ca	6.692	7.075	0.11	0.240
Mg	3.438	3.473	0.09	0.789
S	6.972	7.541	0.35	0.262
Cu	19.523	21.631	1.13	0.200
Fe	57.161	64.472	3.002	0.099
Zn	8.99	9.22	2.83	0.584
Na	23.48	25.12	5.96	0.063

Diet 1—without Parkia platycephala pod (30% Tifton hay + 20% ground corn), and Diet 2—with Parkia platycephala pod (30% Parkia platycephala pod + 0% ground corn); SEM = Standard error of the mean; p-value = Probability value.

. We observed that there was no effect of the diets on the mineral composition of the meat (p > 0.05). The minerals assessed remained within the expected ranges for fresh sheep meat, according to the results reported by Araújo et al. [28]. These findings reinforce the nutritional value of sheep meat as a source of essential micronutrients in the human diet.

The absence of significant differences indicates that the feeding strategy did not impair mineral deposition in muscle tissue. Although Parkia platycephala pods contain tannins, the estimated dietary concentration was low and likely insufficient to reduce mineral bioavailability or mineral accumulation in the muscle. Tannins are known to chelate divalent minerals such as iron and zinc, potentially reducing their bioavailability and tissue deposition [39]. However, no differences were observed in the mineral composition of the Semimembranosus muscle between treatments in the present study (Table 4). This response may be associated with the relatively low concentration of tannins effectively supplied in the experimental diet. Considering the inclusion level of 30% Parkia platycephala pod in the diet and the tannin concentration reported for the ingredient, the diet contained approximately 3.15 g/kg dry matter (DM) of total tannins and 0.48 g/kg DM of condensed tannins, values considerably lower than concentrations commonly associated with marked antinutritional effects in small ruminants (>55 g/kg DM; [40]). Therefore, the low tannin concentration used under the present experimental conditions was insufficient to produce detectable antinutritional effects on the mineral profile of the Semimembranosus muscle.

Although the present study did not include an economic evaluation of the diets, the use of Parkia platycephala pod may represent a potentially viable alternative feed resource in regions where this species is naturally abundant. Previous studies have demonstrated that Parkia platycephala pods can replace conventional feed ingredients such as corn without impairing animal performance or carcass traits [9]. However, because no feed cost analysis or economic efficiency assessment was performed in the present study, conclusions regarding the economic viability of this feeding strategy should be interpreted cautiously. Therefore, further studies evaluating feed costs, economic return, and production efficiency are necessary to confirm the practical economic benefits of including Parkia platycephala pod in sheep diets.

4. Conclusions

Under the present experimental conditions, the feeding strategy including Parkia platycephala pod and whole corn grain did not significantly affect the physicochemical characteristics, proximate composition, or mineral profile of the Semimembranosus muscle.

Therefore, Parkia platycephala pod may be considered a potential alternative feed resource for sheep diets without evident detrimental effects on the evaluated meat quality parameters. However, the relatively small sample size and the absence of detailed fatty acid profiling should be considered when interpreting the results. Further studies involving larger experimental populations and comprehensive lipid characterization are recommended to better understand the effects of Parkia platycephala pod on the nutritional quality of sheep meat.