Effects of Varying Levels of Baobab Oilseed Cake Combined with Fossil Shell Flour Diets on Nutritional Status Indicators and Associated Blood Metabolites of Angora Goats

Simple Summary

Rising feed costs and limited access to quality resources are challenges for goat farmers. The study investigates the varying levels of baobab oilseed cake (BOSC), a by-product of baobab oil extraction, combined with a fixed level of fossil shell flour (FSF), a mineral-rich powder derived from marine fossils, on the nutritional status of goats. Angora goats were fed fossil shell flour diets with varying levels of baobab oilseed cake. The results showed that goats fed the highest level of baobab oilseed cake improved their nutritional status. These findings suggest that incorporating natural, locally available feed resources into goat diets can support better nourishment. This offers a cost-effective and sustainable approach to enhancing productivity in goat farming, particularly in resource-constrained rural areas.

Abstract

The present study determined the effects of varying inclusion levels of baobab oilseed cake (BOSC) combined with fossil shell flour (FSF) diets on body condition scores, body weight gain, and nutritionally related blood metabolites of Angora goats. Twenty-four Angora goat wethers aged 5–6 months, weighing 12.75 ± 1.5 kg, were kept in individual pens for 105 days of successive feeding, including a 14-day adaptation period. Goats were randomly allocated to four dietary treatments: 0%, 5%, 10%, and 15% BOSC (n = 6). Each goat was offered experimental diets at 4% of its body weight daily at 08:00. Goats were then released to graze on natural pastures at 10:00 and returned to their respective pens at 16:00 daily. Body weight gain, body condition scores, and blood concentrations were determined. Angora wethers BCS linearly increased (p < 0.05) as weeks progressed in all inclusion levels of BOSC. Body weight gain increased linearly (p < 0.05) in goats fed 0% and 10% BOSC across the 13-week feeding period, while goats fed 5% BOSC showed a sharp quadratic increase (p < 0.05) between weeks 5–6 and those fed 15% BOSC between weeks 3–8. Creatinine levels showed a sharp quadratic decline (p < 0.05) between 10–15% BOSC inclusion, while urea levels quadratically declined (p < 0.05) between 0–5% inclusion. Phosphorus concentrations also decreased quadratically (p < 0.05), reaching their lowest values between 5% and 10% BOSC, while total protein, glucose, magnesium, albumin, and calcium remained unchanged (p > 0.05) across dietary treatments. In conclusion, this preliminary study suggests that the inclusion of 15% BOSC improves BWG, BCS, and nutritionally associated blood metabolites in Angora goats. Further studies with a larger number of animals are recommended to confirm these findings.

1. Introduction

Angora goat (Capra hircus; Angora breed) are mostly kept under extensive or semi-extensive systems in commercial farms to emphasise browsing and grazing on natural pastures, according to [1,2]. Although these systems are cost-effective, they often fail to meet the nutritional requirements of livestock at various physiological stages [3,4]. Hence, farmers often supplemented the animals’ diets with concentrates. However, due to land degradation and competition with human activities, the rising cost of conventional feed ingredients has significantly challenged both commercial and resource-poor farmers. Angora goat farming in South Africa is a well-established industry, with the country being the world’s leading mohair producer, particularly in the Karoo regions, while also experiencing growing success in the North West, Gauteng, and Eastern Cape Provinces [5,6]. South Africa has approximately a million Angora goats [7,8]. Effective grazing management is crucial to support animal welfare, enhance productivity, and improve nutritional status. Mtenjwa et al. [6] reported that Angora goats require specific quantities of protein, energy, vitamins, and mineral elements to satisfy their dietary requirements. Mpyana [9] and Nipane et al. [10] reported that Angora goats thrive better when fed Lucerne hay than other hay types in South Africa. Additionally, [11] noted that providing Angora goats with dry matter equivalent to approximately 4% of their body weight, primarily through pasture or hay, benefits their growth, nutritional status, and overall productivity. However, while the feed quantity may be sufficient, the feed may lack optimal nutrient matrices, necessitating the incorporation of alternative feed sources, such as baobab oilseed cake.

Accurate evaluation of nutritional status is crucial for monitoring productivity and the overall well-being of animals. Wu [12] stated that nutritional status can indicate metabolic diseases and aid in diagnosing conditions that can be improved with a balanced diet. Although body weight (BW) and body condition scores (BCSs) are primarily used to evaluate nutritional status, however; some shortcomings have led to the popularity of blood metabolites in assessing nutritional status in livestock [13]. Blood metabolites indicate the extent of metabolism of energy, protein, minerals, and other nutrients in animals [12,14]. The concentration of blood metabolites adequately reflects the nutrient supply and the efficiency of utilisation in goats, according to [15]. In this study, creatinine (a measure of muscle and kidney function), total protein and albumin (indicators of protein status), glucose (an indicator of energy status), urea (a marker of protein metabolism), and calcium, magnesium, and phosphorus (markers of mineral status) were measured as sensitive indicators of the animals’ nutritional and metabolic status. Incorporating BCS, BW, and blood metabolites enhances accuracy in evaluating ruminants’ nutritional status and welfare [16,17]. Understanding the assessment of nutritional status and its accuracy is essential. Moreover, identifying influential factors such as the type and quality of animal feed is crucial.

Adedokun & Olojede [18] reported that the quantity and quality of livestock feeds directly affect the nutritional status and influence productivity. Similarly, ref. [19] reported that adequate nutrient intake and good management are key factors to achieve optimal productivity in goats. Therefore, enhancing Angora goat nutrition and productivity requires high-quality diets, optimised grazing, concentrate supplementation, and sustainable feeding, as recommended by [20,21]. The safety and sustainability of livestock diets are essential fundamentals of safety for the entire food chain. Untea et al. [22] have noted that relying solely on conventional livestock feed ingredients and non-natural feed additives can be less effective and pose risks to animals, humans, and the environment than natural alternatives. Recent studies by [19,22] have reported that including natural feed additives, such as fossil shell flour (FSF), and non-conventional feed ingredients, such as baobab oilseed cake (BOSC), enhances the nutrient absorption and bioavailability of microminerals. Fossil shell flour is a silica-rich, natural powder from fossilised diatoms, supporting mineral balance and improving livestock nutrient absorption [23,24]. According to [25], baobab oilseed cake, a protein- and mineral-dense byproduct of baobab seed oil extraction, improves nutritional status by enhancing protein intake and micronutrient availability in small ruminants. Baobab oilseed cake contains substantial crude protein and moderate fiber, though it may also have anti-nutritional factors such as phytates, tannins, saponins, and oxalates [25]. In this study, the BOSC was mechanically pressed to extract the oil and subsequently defatted to reduce lipid content and improve its suitability for inclusion in Angora goat diets.

A combination of FSF and BOSC could provide balanced diets that meet protein and mineral requirements, supporting metabolic efficiency without relying on synthetic additives or conventional protein sources. Fossil shell flour diets supplemented with BOSC are natural, widely available, cost-effective, and eco-friendly. Such feed materials can ensure sustainable and safe feeding practices for emerging and commercial farmers [25,26]. Establishing a replacement for non-natural additives and conventional protein sources such as soybean meal in livestock diets could enhance nutritional status and productivity while helping to prevent environmental pollution. The present study might assist Angora goat farmers in gaining knowledge on the formulation of custom feeds comprising FSF and BOSC to improve nutrition. Therefore, the current study investigated the impact of varying inclusion levels of baobab oilseed cake combined with fossil shell flour diets on the nutritional status of Angora goats. It was hypothesised that the varying inclusion levels of baobab oilseed cake combined with fossil shell flour diets would significantly improve body weight gain, body condition scores, and concentrations of creatinine, total protein, albumin, glucose, urea, calcium, magnesium, and phosphorus in Angora goats.

2. Materials and Methods

2.1. Study Site

The experiment was conducted at Driefontein Farm, located in the town of Somerset East, in the Karoo region of the Eastern Cape Province, South Africa. The farm is situated at −32.72° S, 25.59° E, at an elevation of 519 m above sea level. The area is dry for 240 days a year, with a humidity level of about 35 percent. Annual rainfall is approximately 660 mm, with temperatures of about 21 °C. Driefontein Farm is dominated by the shrub Pentzia incana vegetation.

2.2. Goats Management, Feeding, and Experimental Design

Twenty-four Angora goat wethers (5–6 months old; 12.75 ± 1.5 kg) were housed individually in well-ventilated 1.5 × 1.5 m wooden-floored pens for 105 days of successive feeding, including the first 14 days of an adaptation period. Each goat was ear-tagged and administered with Valbantel pour-on at a dosage of 2 mL per 10 kg body weight for internal parasites before the commencement of the study. Goats were offered experimental diets at 08:00, equivalent to 4% of their body weight daily. The goats were released for grazing at 10:00 and returned to the pens at 16:00 to resume feeding on the test diets. Clean water was offered in graduated 8-liter buckets. All dietary treatments contained 4% of fossil shell flour (FSF) of concentrate DM, based on previous studies recommending a 4% FSF inclusion level to enhance performance and overall productivity in small ruminants [24]. The current study incorporated a mechanically pressed and subsequently defatted baobab oilseed cake (BOSC) at varying inclusion levels across treatments: T1 (0%), T2 (5%), T3 (10%), and T4 (15%) of the total diet. Before use, it was oven-dried to preserve nutrient composition and minimise alterations in anti-nutritional factors. The study was conducted using a completely randomised design, in which four dietary treatments were assigned to six goats each (n = 6) using simple randomisation. There were no morbidity, mortality, or adverse events during the 105-day trial.

Table 1. The mineral composition of fossil shell flour (FSF).

Items	Content
Dry Matter %	93.00
% Calcium	0.40
% CaO (calculated from %Ca)	0.55
% Magnesium	0.21
%MgO (calculated from %Mg)	0.34
Potassium%	0.16
Copper (mg/kg)	30.00
Sodium (mg/kg)	923.00
Zinc (mg/kg)	118.00
Iron (mg/kg)	7944.00
Manganese (mg/kg)	69.00
Phosphorus (as P2O5)	0.04
Sulfate Sulfur (S)%	0.06
Aluminium (Al) %	0.07
Vanadium (V) %	0.00438
Boron (B) %	0.0023

Sourced from [24].

and

Table 2. The proximate composition of baobab oilseed seedcake.

Nutrient	Content
Dry Matter (%)	90.47
Moisture (%)	9.53
Organic Matter (%)	83.75
Crude Protein (%)	25.28
Crude Fiber (%)	12.88
Ether Extract (%)	5.92
Ash (%)	6.72
ADF (%)	25.23
NDF (%)	43.53
Total Nitrogen (%)	4.05
Starch (%)	16.42
Phosphorus (%)	0.07
Calcium (%)	0.79
Magnesium (%)	0.79
Sodium (mg/kg)	8.00
Copper (mg/kg)	12.00
Iron (mg/kg)	65.00
Manganese (mg/kg)	7.00
Dry Matter (%)	90.47

below show the proximate analyses of the fossil shell flour and baobab oilseed cake diets, respectively.

Table 3. The approximate chemical composition of the experimental diets of all four dietary treatments.

Ingredients	Experimental Diets
	0% BOSC	5% BOSC	10% BOSC	15% BOSC
Dry Matter (g/kg)	88.96	88.72	88.73	88.83
Organic Matter	79.68	79.88	79.95	79.52
Moisture	11.04	11.28	11.27	11.17
Crude Protein	13.3	12.91	12.67	11.57
Ether Extract	1.79	1.82	2.04	1.98
Ash	9.32	8.84	8.78	9.31
ADF	17.47	21.34	31.08	41.70
NDF	39.11	51.09	51.22	59.10
Nitrogen	2.13	2.07	2.03	1.85
Starch	10.68	10.02	10.62	9.79

presents the proximate analyses of the test diets as fed.

2.3. Feed Analytical Procedure

The dietary treatments and baobab oilseed cake were analysed for proximate composition, including dry matter, ash, organic matter, crude protein, ether extract, crude fiber, and gross energy, approximately following standard AOAC procedures.

Blood Collection Procedure

Blood was collected from three animals per treatment on day 91 of successive feeding before the 08:00 feeding. A blood collection kit, which included gloves, a syringe, needles, a vacutainer, and sterile alcohol wool, was used for collecting samples [13,27]. Eight milliliters of blood per animal was drawn from the jugular vein using a Luer lock syringe (6 mL capacity) and 21-gauge 1 1/2-inch needles that lock into evacuated vacutainer tubes. Red-top and yellow-top Vacutainer tubes were used for serum (total protein, albumin, urea, creatinine, calcium, magnesium, and phosphorus). In contrast, green-top anticoagulant-treated tubes were used for plasma (for glucose). Immediately after blood collection, the injection site was disinfected with sterile alcohol-soaked wool. Blood was transported to Victoria Hospital Laboratory for analysis in a cooler box with soft ice bricks (Seagull brand).

2.4. Measurements

2.4.1. Body Weight Gain

All 24 goats were weighed on day 1 of the experiment to determine their initial weight and were weighed weekly to monitor body weight changes. The animals were weighed on day 91 of the experiment, before the 8:00 feeding, to determine their final body weight. The difference between the initial and final weights was calculated as body weight gain (BWG) weekly [15,28]. The formula is given below:

$$BWG=Finalbodyweight-Initialbodyweight$$

(1)

2.4.2. Body Condition Score

The body condition score of each goat (24 goats) was assessed using a scale of 1 to 5 fortnightly. The BCSs were measured visually using palpation by a trained animal handler, based on the five-point scoring system, where 1 is emaciated (very thin), 2 is thin, 3 is average, 4 is fat, and 5 is obese as described by [28,29].

2.4.3. Blood Metabolites

Upon arrival in the laboratory, blood samples were left at room temperature to allow for coagulation for 30 min. A total of 5 mL of blood sample was centrifuged at 3500 revolutions per minute for 10–15 min to collect the serum. The serum samples were kept at −20 °C pending chemical analyses. Samples were analysed using a commercial kit (Assel, Rome, Italy) and a Chex CK machine [15,28]. Enzymatic methods using the NAE2-27 reagent were employed to determine Glucose in plasma. The serum was analysed spectrophotometrically for total protein and albumin (Humalyzer 3000; Human GmbH, Wiesbaden, Germany) using colorimetric methods. Serum concentration of calcium, phosphorus, and magnesium was analysed using a 100/300 atomic absorption spectrophotometer.

2.5. Statistical Analysis

Data on the effects of varying inclusion levels of BOSC combined with FSF diets on body weight gain and Body condition scores were analysed using PROC MIXED of the Statistical Analysis System (SAS) (Version 9.3, 2010). Blood metabolite concentrations (creatinine, total protein, albumin, glucose, urea, calcium, magnesium, and phosphorus) were analysed using PROC GLM of the SAS (Version 9.3, 2010). Animals were treated as a random effect. The PDIFF option of SAS was used to compute significant differences among least square means. The means were considered significantly different at p ≤ 0.05. A regression analysis test was run to generate relationships amongst dietary inclusion levels of BOSC, weeks of successive feeding, BWG, BCS, and blood metabolite concentrations (creatinine, total protein, albumin, glucose, urea, calcium, magnesium, and phosphorus). The linear model used is as follows:

Y_ijk = u + M_i + W_k + (M + W)_ijk + E_ijk

(2)

where

• Y_ijk = Observation (BSC, BWG, Blood metabolites);
• U = Overall means common to all observations;
• M_i = Effect of BOSC inclusion level;
• W_k = Effect of feed weeks;
• (M × W)_ijk = Interaction between treatment and week;
• E_ijk = Random error for _i and _j = 1, 2, 3, 4, and K = 1.

3. Results

Table 4. Body condition scores (BCSs) of Angora goats fed different inclusion levels of baobab oilseed cake in FSF diets across 13 weeks of the trial.

Parameter	Diets (%BOSC)	Weeks of the Trial							SEM	Contrasts		Sign
		1	3	5	7	9	11	13		Linear	Quadratic
BCS	0	1.833	2.000	2.167	2.500	2.833	2.833	3.167	0.191	0.0002	0.7897	**
	5	2.000	1.833	2.000	2.000	2.500	2.667	3.000	0.191	0.0115	0.0517	*
	10	1.833	1.833	2.000	2.500	3.000	3.000	3.000	0.191	0.0046	0.8647	*
	15	2.000	2.167	2.167	2.500	2.833	3.167	3.333	0.191	0.0005	0.3690	**

** means p ≤ 0.01, * means p ≤ 0.05.

and Figure 1 show results on body condition scores (BCSs) amongst goats fed incremental dietary inclusion levels of BOSC. The BCS linearly increased to its highest values amongst goats fed 15% BOSC (p < 0.05).

Table 5. Mean values of body weight gain (BWG) of Angora goats fed diets containing different inclusion levels of BOSC over 13 weeks of successive feeding.

Parameter	Diets(%BOSC)	Successive Weeks of Feeding													SEM	Contrasts		Sign
		1	2	3	4	5	6	7	8	9	10	11	12	13		Linear	Quadratic
BWG (kg)	0	0.667	0.750	0.750	0.750	0.833	1.227	1.324	1.454	1.549	1.650	1.765	1.870	2.020	0.138	<0.0001	0.6628	**
	5	0.533	0.667	0.833	1.033	1.185	1.450	1.581	1.660	1.717	1.768	1.783	1.838	1.967	0.138	<0.0001	0.0038	**
	10	0.683	0.683	0.967	1.067	0.900	1.287	1.413	1.503	1.583	1.705	1.804	1.919	2.076	0.138	<0.0001	0.3842	**
	15	0.617	0.667	0.819	1.182	1.358	1.559	1.647	1.729	1.846	1.972	2.045	2.110	2.255	0.138	<0.0001	0.0001	**

** means p ≤ 0.01.

and Figure 2 show body weight gain (BWG) amongst goats fed varying dietary inclusion levels of BOSC over 13 weeks of successive feeding. Body weight gain in goats fed 0% and 10% BOSC inclusion levels showed a linear increase (p < 0.05) across the 13 weeks of successive feeding. Goats fed 5% BOSC inclusion level showed a sharp quadratic increase (p < 0.05) between weeks 5 and 6 in BWG. In addition, goats fed 15% BOSC inclusion level showed a sharp quadratic increase between week 3 and 8 (p < 0.05).

Table 6. Mean values of blood metabolites of Angora goats fed diets with varying levels of BOSC for 91 days.

Parameters	Diets				SEM	Contrasts		Sign
	0%BOSC	5%BOSC	10%BOSC	15%BOSC		Linear	Quadratic
Glucose (mmol/L)	3.05	4.25	4.55	3.60	0.521	0.692	0.560	NS
Albumin (g/L)	13.50	14.50	14.00	14.50	0.968	0.480	0.655	NS
Creatinine (umol/L)	50.00	48.50	46.50	33.50	6.359	0.013	0.026	*
Total protein (g/L)	69.00	60.50	61.00	74.50	4.168	0.573	0.286	NS
Urea (mmol/L) H	10.65	9.95	9.35	8.80	0.646	0.002	0.044	**
Calcium (mg/dL)	10.60	9.19	9.50	11.25	0.504	0.736	0.516	NS
Magnesium (mg/dL)	2.30	1.79	2.10	2.42	0.193	0.790	0.829	NS
Phosphorus (mg/dL)	6.35	5.70	5.61	6.69	0.450	0.074	0.017	*

** means p ≤ 0.01, * means p ≤ 0.05, NS means Not significant.

presents the nutritionally related blood metabolites of Angora wethers across various dietary treatments. Creatinine levels showed a sharp quadratic decline (p < 0.05) between 10 and 15% inclusion levels of BOSC. The highest urea level was observed at 0% BOSC, followed by a sharp quadratic decline (p < 0.05) between 0% and 5% BOSC inclusion level. Phosphorus concentrations quadratically decreased (p < 0.05), reaching the lowest values at inclusion levels between 5% and 10% inclusion levels of BOSC. Total protein, glucose, magnesium, albumin, and calcium were the same across the treatment inclusion levels tested (p > 0.05).

4. Discussion

4.1. Body Weight Gain and Body Condition Score

Body weight gain (BWG) and body condition scores (BCSs) are essential indices of nutritional status in livestock. Together, they provide practical and measurable insight into how well the dietary needs of livestock are being met under different feeding regimes [24,30]. The present study assessed the influence of varying inclusion levels of baobab oilseed cake (BOSC) combined with fossil shell flour (FSF) diets on Angora goats’ nutritional status parameters (BWG, BCS, Blood metabolites). Findings that BCSs and BWG increased (p < 0.05) across all experimental diets as the weeks of successive feeding progressed suggest that the diet enhanced sufficient nutrient intake and utilisation over time. These results further indicate that the nutritional effects of the diet became more evident as feeding continued. In addition, the lower body condition scores and weight gain observed in the early weeks may be attributed to the freezing weather, consistent with [31,32], who reported reduced weight gain and body condition scores in Angora goats under cold conditions. The current study aligns with [33], who concluded that supplementing with a protein source (oilseed cakes) increases small ruminant body condition scores and weight gain. This might be attributed to sufficient dietary protein and improved nutrient availability in the bloodstream, which enhances metabolic processes that support tissue accretion and body reserves. Obeidat & Thomas [34] asserted that protein enhances feed efficiency, increases body mass and metabolic functions, improving body condition scores and weight gain. In addition, the current research results also agree with [24], who concluded that Dohne Merino wethers fed diets with 4% FSF body condition scores had significantly increased BWG. These results may be attributed to FSF enhancing BCS and BWG in livestock by providing essential trace minerals, improving gut health, promoting nutrient absorption, and enhancing overall nutritional status [23].

4.2. Glucose

Blood metabolites are the most accurate parameters for animal nutritional status assessment [35,36]. According to [37], blood metabolites are small molecules in the serum that reflect an animal’s nutritional status and overall health. Among them, glucose concentration in goats’ blood shows how well animals are nourished, as it reflects the energy they get mainly from converting rumen-derived products into sugar [38]. The study results showed that glucose levels ranged between 3.05 and 4.55 mmol/L across Angora goats fed different inclusion levels of BOSC, with no significant difference observed (p > 0.05). The results obtained in this study are slightly above the normal standard range of 2.78–4.17 mmol/L for goats as reported by [39]. The difference in ranges could be due to the fact that blood glucose concentration is influenced by feeding regime, breed, and environment [39], which reflects breed-related differences in glucose metabolism, environmental stress that elevates cortisol and stimulates gluconeogenesis, and dietary effects that increase propionate production and glucogenic substrate availability. Collectively, these factors enhance hepatic glucose synthesis and are more indicative of a normal physiological adaptation than a metabolic disorder. In addition, high glucose levels may result from saponins in BOSC altering rumen fermentation to increase propionate production, thereby enhancing hepatic gluconeogenesis [40]. The current study’s results on glucose levels agree with [41], who reported that glucose levels were not different in Angora goats fed concentrates during the transition period.

4.3. Albumin

The liver produces blood albumin, a plasma protein that reflects an animal’s nutritional status, as its levels are directly proportional to protein-energy deficiencies and poor nutrient availability [42,43]. The present study albumin results on Angora goat wethers fed varying inclusion levels of BOSC ranged between 13.5 and 14.5 g/L (p > 0.05), which is below the normal range of 27–38 g/L reported by [39]. The study results may suggest that protein-energy intake was inadequate or that metabolic stress occurred, leading to lower albumin levels. Furthermore, the low albumin levels observed in goats fed BOSC could be associated with the presence of anti-nutritional factors, such as saponins, tannins, and phytates, which can impair protein digestibility and nutrient utilisation, as reported by [44]. These compounds can reduce protein utilisation by forming complexes with dietary proteins, thereby affecting protein quality or overall intake, which can decrease the availability of amino acids for hepatic protein synthesis. Physiological stress, including environmental or handling stress, may further alter protein metabolism by increasing catabolism and reducing albumin production. Seasonal variations in feed availability and nutrient composition can also affect liver function and overall nutritional status, contributing to lower circulating albumin concentrations. The study aligns with [45], who investigated the effects of supplementing finishing goats with feed additive (Mitragyna) speciosa (Korth) Havil leaves powder on hematological parameters and concluded that albumin was not significant in goats fed a feed additive; however, the albumin ranges were within the normal range.

4.4. Urea and Creatinine

Blood urea and creatinine are the primary nitrogenous waste products in the blood, indicating protein metabolism and kidney function [46]. Urea and creatinine serum concentrations decreased with increasing BOSC inclusion levels, providing further insight into the metabolic processes and nutritional status of Angora goats. The study results on urea and creatinine serum concentrations may indicate effective protein metabolism, suggesting that the dietary requirements of Angora wethers were met. The current study’s findings on creatinine and urea are in agreement with [47], who reported that blood creatinine and urea levels are low in goat kids; however, diet can significantly influence these levels. This may be because creatinine and urea reflect protein intake, as noted in [48]. Diets containing different protein sources can change metabolism and eliminate nitrogenous waste products, such as creatinine and urea, by affecting kidney function, protein breakdown, and nitrogen excretion [26]. Furthermore, an increase may be attributed to excess protein levels in the animal’s rumen, which can be broken down into ammonia and transported by the blood as urea to the renal organs, as reported by [47].

4.5. Total Protein

Total serum protein concentration indicates the total amount of proteins in the blood serum, which includes albumin and globulins, and reflects the animal’s nutritional status, liver condition, and protein metabolism process [49]. The current study revealed that total protein levels in the blood of Angora goats ranged from 60.5 to 74.5 g/L across varying BOSC inclusion levels. The present research study results for total protein in goats are within the normal range, varying between 60 and 79 g/L [39,47], which is consistent with the reported normal ranges in goats for total protein, which typically range between 60 and 70 g/L. This suggests that BOSC supplementation provided sufficient protein without negatively affecting protein metabolism and liver function. The current study is consistent with [44], who concluded that total protein was not significant in goats fed varying levels of feed additive (Mitragyna leaf), ranging between 60 and 62 g/L.

4.6. Calcium

Calcium is an essential nutrient that promotes overall well-being by enhancing bone strength, supporting muscle contractions, maintaining proper nerve function, and regulating metabolic balance, making it a vital indicator of nutritional status [50]. The findings of the present research on calcium levels ranged from 9.19 to 11.25 mg/dL in angora goats fed varying levels of BOSC. The study results are within the normal range (around 9–12 mg/dL) of calcium in goats, as reported by [45]. This suggests that BOSC inclusion did not disrupt calcium homeostasis, indicating a sufficient dietary mineral supply and normal bone metabolism in the goats. The study observations contrast with those of [51], who investigated the effects of age and sex on some hematological and biochemical parameters in Hair goats and observed high calcium levels in the blood of male kids. This may be attributed to the different environments, seasons, and feed provided to goats.

4.7. Magnesium

Magnesium is an essential nutrient that supports metabolic processes, muscle and nerve function, and bone health, making it a key indicator of an animal’s nutritional status [52]. The experimental findings on the Mg concentration in the blood of Angora goats range from 1.79 to 2.42 mg/dL across varying inclusion levels of BOSC. The serum magnesium (Mg) concentration results in this study are below the normal ranges cited in [46], indicating that the Mg concentration should be between 2.8 and 3.6 mg/dL, regardless of the diet provided. Similarly, the present research outcomes are consistent with [52], whose Magnesium concentration observations were non-significant and ranged around 2.11 ± 0.26 mg/dL in male hair goat kids. The slightly low magnesium concentration may suggest that the body used more magnesium for body functions and mohair production.

4.8. Phosphorus

Goats that rely solely on natural pastures, mainly in the semi-arid Karoo regions, are affected mostly by phosphorus deficiency [53]. Phosphorus is an essential mineral, second only to calcium in animal nutrition, primarily stored in bones and teeth, with the remainder present in body fluids and soft tissues [54]. The phosphorus concentrations observed in this study fall within the normal range reported by [46], where healthy goats typically exhibit blood phosphorus levels between 4.2 and 9.1 mg/dL. Froghi & Hosaini [53] noted that most protein source supplements contain a significant level of phosphorus, making supplementation in goats more important for enhanced nutritional status, body condition, and overall productivity. This may be because dietary phosphorus is directly affected by feed composition, and phosphorus may be higher in the diet with a higher inclusion level of protein source. In addition, a study by [51] concluded that phosphorus was significant in male kids of hair goats, with a range of 8.71 ± 2.02, which is consistent with the current study’s observations. The observed results may be due to active homeostatic regulation, suggesting satisfactory nutritional status across all diets.

5. Conclusions

In conclusion, fossil shell flour diets supplemented with baobab oilseed cake can be fed to goats to improve nutritional status. The diet supplemented with 15% BOSC observed the highest body condition and body weight gain in Angora goats. The serum concentrations of creatinine, urea, and phosphorus varied across diets, whereas glucose, calcium, magnesium, total protein, and albumin remained constant. Conducting the same experiment during the summer may be necessary to validate the results of this study. As this is a preliminary study, future research could investigate BOSC inclusion levels above 15% to assess their effects in Angora goats. In addition, increasing the number of goats used in the trial would enhance the reliability of the findings. It is also recommended that future research quantitatively measure pasture intake composition to better understand its contribution to the animals’ overall nutrient intake.