Use of Fig Seed Meal as a New Alternative Feed Source in Quails: Effect on Growth Performance, Carcass Characteristics, Antioxidant Capacity and Serum Biochemistry

ABSTRACT

This study aims to evaluate the potential of fig seed meal (FSM), which contains approximately 20% crude protein (CP) and provides 2106 kcal/kg of metabolizable energy (ME), as an alternative protein source in the diets of broiler Japanese quails (Coturnix coturnix japonica). One hundred sixty 1‐day‐old mixed‐sex quails were divided into four groups, each with four replicates, and fed diets containing 0% (control), 2.5%, 5.0% and 10.0% FSM for 35 days. Weekly growth performance parameters were recorded, and carcass characteristics and blood biochemical parameters were analysed at the end of the trial. Including up to 10% FSM did not affect feed intake (FI) (p > 0.05), but linear, quadratic and cubic effects were observed in body weight gain (BWG). Adding up to 5% FSM resulted in growth performance similar to the control group, whereas the 10% FSM diet significantly reduced BWG. FSM levels influenced the feed conversion ratio (FCR) linearly, quadratically and cubically, with a decline observed at levels above 5%. In female quails, 5% FSM increased breast and thigh weights, whereas in males, it reduced carcass yield and intestinal weight. There were no statistically significant differences in other carcass traits among the groups. Serum biochemical parameters and oxidant/antioxidant balance were not adversely affected by FSM inclusion up to 5%. In conclusion, using FSM up to 5% did not negatively impact growth performance, but higher inclusion levels reduced performance.

This study investigates the effects of fig seed meal (FSM; 20% CP, 2106 kcal/kg ME) as a protein source in broiler quail diets. A total of 160 quails were fed diets with 0%, 2.5%, 5% and 10% FSM for 35 days. Growth performance was not affected up to 5% inclusion, whereas 10% FSM reduced body weight gain and impaired feed efficiency. Carcass traits were sex‐dependent: Overall, 5% FSM increased breast and thigh weights in females but reduced carcass yield in males. Serum biochemical and oxidant/antioxidant parameters remained stable up to 5% FSM. FSM can be safely included up to 5% in broiler quail diets without compromising performance or health.

1. Introductıon

Investigating and utilizing alternative feed sources is essential for sustainable animal production systems, especially in the face of increasing environmental and economic challenges (Bayril and Eroglu 2023). However, as the demand for animal‐based products grows globally, the pressure on conventional protein sources intensifies. This growing demand not only threatens the long‐term availability and affordability of traditional feed ingredients but also raises concerns about competition with human food sources (Yu et al. 2024). In recent years, various agro‐industrial by‐products, such as jujube fruit residues (Eroglu et al. 2024; Yang et al. 2023), olive cake (Al‐Harthi and Attia 2015) and grape pomace (Costa et al. 2022), have been investigated as alternative feed ingredients in poultry nutrition due to their nutritional value and potential functional properties. In this context, by‐products from the fruit processing industry represent potential resources for use in animal nutrition. These by‐products can serve as alternative feed ingredients due to their nutrient content. The fig (Ficus carica L.) is one of the oldest cultivated fruits, grown in many regions of the world, particularly in temperate zones (Cihat Icyer et al. 2017; Hssaini et al. 2020; Tufan et al. 2023). The Mediterranean region, including Türkiye, plays a significant role in fig production (Alan et al. 2024; Cihat Icyer et al. 2017; TAŞ 2019). Studies have shown that figs are rich in potassium, calcium and iron minerals (Alan et al. 2024; Aljane et al. 2007; Baygeldi et al. 2021) and, in addition to these minerals, are also a good source of riboflavin and thiamine vitamins (Amessis‐Ouchemoukh et al. 2017; Baygeldi et al. 2021; Cihat Icyer et al. 2017; Guvenc et al. 2009; Mawa et al. 2013; TAŞ 2019; Tufan et al. 2023). The high fat and protein content of fig seeds and their rich composition of fatty acids and essential amino acids make them a product with potential health benefits (Hssaini et al. 2020; Oliveira et al. 2010, 2009; Slatnar et al. 2011; Slavin 2006). The seeds in fig fruits can vary in size, and the number of seeds per fruit ranges from 30 to 1600 (Badgujar et al. 2014; Lansky et al. 2008). In addition, fig seeds are reported to be a rich source of carbohydrates, with studies showing that their carbohydrate content ranges from 52.62% to 53.66%. The fat content of fig seeds is over 30%, primarily composed of linolenic acid, along with linoleic acid, palmitic acid and stearic acid (Badgujar et al. 2014; Barolo et al. 2014; Cihat Icyer et al. 2017; TAŞ 2019). Fig seed oil is utilized for its health‐promoting properties (Cihat Icyer et al. 2017; Mawa et al. 2013), and the residual material remaining after oil extraction qualifies as a meal. The rising costs of conventional protein feed sources have driven producers to seek alternative, cost‐effective feed ingredients to ensure the sustainability of animal husbandry (Irmak et al. 2024). In this regard, fig seed meal (FSM) is considered a potential feed ingredient for poultry. Literature reviews on FSM reveal that no studies have been conducted on its use as a feed ingredient in poultry.

Quail diets containing FSM may have the potential to support adequate nutrient intake and sustainable dietary practices and offer a promising alternative to traditional protein sources.

This study investigates the effects of supplementing FSM as an alternative feed ingredient in broiler quail diets on growth performance, carcass parameters, oxidant–antioxidant capacity and specific biochemical blood parameters.

2. Materials and Methods

2.1. Animals and Experimental Design

This study used 160 one‐day‐old broiler Japanese quail (Coturnix coturnix japonica) chicks as the animal material. The animals were randomly divided into four groups based on their initial body weights (BWs) to ensure homogeneity among groups in the experiment; each consisted of 10 replicates, with four animals per replicate. The control group was fed a basal diet containing no FSM, whereas the other experimental groups were fed diets containing FSM at 2.5%, 5.0% and 10.0%, respectively. The experimental group diets were formulated as iso‐nitrogenous and iso‐caloric, containing 24% crude protein (CP) and 2900 kcal metabolizable energy (ME) per kilogram of feed (Table 1). The study was conducted in a fully automated experimental unit with complete environmental control. The necessary heating was provided for quail, and lighting was maintained for 24 h. Additionally, feed and water were provided ad libitum. This research was carried out over 35 days, and all trials were conducted under controlled cage conditions. The study was conducted in five consecutive phases: Days 1–7, 8–14, 15–21, 22–28 and 29–35.

TABLE 1.

Nutrient contents (%) obtained through analysis and calculation methods in the ingredients of the mixed feed formulation.

	Fig seed meal, %
Raw materials	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00
Sunflower oil	1.89	2.20	1.80	2.00
Maize	50.00	48.15	48.89	47.00
Sunflower meal (23% CP)	3.00	2.15	0.25	0.00
Soybean meal (48% CP)	34.00	33.30	33.80	34.94
Cottonseed meal, expeller, (32% CP)	8.05	8.64	7.20	3.00
Fig seed meal	0.00	2.50	5.00	10.00
DCP	0.65	0.65	0.65	0.65
dl‐methionine	0.20	0.20	0.20	0.20
l‐lysine	0.10	0.10	0.10	0.10
l‐Treonin	0.15	0.15	0.15	0.15
NaCl	0.40	0.40	0.40	0.40
CaCO3	1.31	1.31	1.31	1.31
Vitamin ve Mineral Premiksi (vitamin and mineral premix)	0.25	0.25	0.25	0.25
	100	100	100	100
Parameters	Values obtained from the analysis
Dry matter	90.00	90.01	89.80	90.05
Crude protein	24.00	24.00	23.9	24.00
Crude fat	3.59	3.86	3.86	3.55
Crude ash	6.08	5.99	6.55	5.51
Crude fibre	4.62	4.41	4.59	2.90
	Calculated chemical composition
ME (kcal/kg)	2900	2902	2900	2901
Ca	0.80	0.80	0.79	0.77
Available P	0.30	0.30	0.29	0.28
Na	0.19	0.19	0.19	0.18
Cl	0.28	0.28	0.28	0.28
Methionine + cysteine	0.99	0.97	0.95	0.92
Lysine	1.35	1.32	1.30	1.27
Threonine	1.04	1.02	1.00	0.97
Tryptophan	0.33	0.32	0.31	0.30
Linoleic acid	2.23	2.37	2.14	2.11
Electrolyte balance (mEq/kg DM)	274	267	259	248

Note: Composition: 240 g Ca and 17.5 g P/kg. Composition (per kg of feed): Vitamin A, 8000 IU; Vitamin D3, 1200 IU; Vitamin E, 10 IU; Vitamin K3, 2 mg; thiamine, 2 mg; riboflavin, 5 mg; pyridoxine, 0.2 mg; Vitamin B12, 0.03 mg; pantothenic acid, 10 mg; niacin, 50 mg; biotin, 0.1 mg; folic acid, 0.5 mg; iron, 80 mg; zinc, 40 mg; manganese, 60 mg; iodine, 0.8 mg; copper, 8 mg; selenium, 0.2 mg; cobalt, 0.4 mg. Composition (per kg of feed): Fe, 80 mg; Zn, 40 mg; Mn, 60 mg; I, 0.8 mg; Cu, 8 mg; Se, 0.2 mg; Co, 0.4 mg.

Abbreviations: CP, crude protein; DCP, dicalcium phosphate; FSM, fig seed meal.

Source: NRC (1994) and TSE (1991).

2.2. Growth Performance Measurements

Growth performance data were measured weekly. Weight gains were determined by weighing the animals individually and calculated as the mean of subgroup replicates (N = 10). Weekly cumulative feed intake (FI) was measured as the mean of subgroup replicates (N = 10). Each cage compartment was considered a subgroup replicate. The feed conversion ratio (FCR) was calculated by dividing cumulative FI by live weight gain:

$$\mathrm{FCR}=\frac{\mathrm{cumulative}\mathrm{feed}\mathrm{intake}\left(\mathrm{g}\right)}{\mathrm{live}\mathrm{weight}\mathrm{gain}\left(\mathrm{g}\right)}\mathrm{was}\mathrm{used}.$$

2.3. Diet Formulation and Feed Analysis

The experimental diets were formulated in accordance with the nutrient requirements for broiler chickens, as reported by NRC (1994). The nutrient content of the compound feeds used in the trial was determined using the Weende analysis method described by Naumann and Bassler (1993), whereas crude fibre was determined using the Lepper method (Bulgurlu and Ergül 1978). The ME content was calculated using the regression equation recommended by TSE Standard No: 9610 (TSE 1991). The main components of the compound feed used in the research consisted of corn, sunflower meal, soybean meal (48% CP), FSM, sunflower oil, dicalcium phosphate (DCP), dl‐methionine, l‐Lysine, NaCl, calcium carbonate (CaCO₃), vitamin and mineral premix. Feed preparation was carried out at a specialized feed manufacturing facility.

2.4. Carcass Evaluation

On Day 35 of the research, quails were separated according to their experimental groups to determine slaughter and carcass parameters, and one quail closest to the group mean was selected from each subgroup. A total of 40 quails were slaughtered and examined for carcass parameters. The measurements included carcass weight (CW) and the weights of the breast, thigh, wing, neck and back, expressed as grams per 100 g of CW. In addition, liver, heart, gizzard, proventriculus, intestine and spleen weights were recorded as grams per 100 g of BW. On Day 35 of the study, blood samples were collected from one quail with a live weight closest to the mean from each subgroup in the dietary group (10 from each main group). Blood samples were centrifuged at 3000 rpm for 10 min, and the obtained sera were stored at −20°C for biochemical analyses.

2.5. Blood Collection and Biochemical Analyses

Total antioxidant status (TAS) and total oxidant status (TOS) levels in serum samples were analysed using commercial kits (Relassay, Türkiye). The oxidative stress index (OSI) values, expressed as the percentage ratio of TOS to TAS levels, were calculated using the formula. Additionally, analyses of serum parameters, including aspartate aminotransferase (AST), alkaline phosphatase (ALP), glucose (Glu), total protein (TP), albumin and cholesterol, were performed using an ADVIA 1800 (Germany) autoanalyser.

2.6. Statistical Analysis

The statistical analysis of the data obtained at the end of the experiment was performed using the SPSS 18.0 software package. Before analysis, the data were tested for normality and homogeneity of variances. One‐way analysis of variance (ANOVA) was conducted using the general linear model (GLM), and Tukey's post hoc test was used to determine statistically significant differences among group means. Results were considered statistically significant at a level of p < 0.05.

3. Results

Table 2 presents the effects of diets containing different levels of FSM on FI at different growth stages of quails. No statistically significant differences (p > 0.05) in FI were observed among the groups at Days 7, 21, 28 and 35, according to the result of the experiment. However, on Day 14, a significant decrease in FI was observed with increasing FSM levels (p < 0.05). During this period, the control group exhibited the highest FI (132.72 g), whereas the FSM‐10.0 group showed the lowest value (113.69 g). Furthermore, linear (L), quadratic (Q) and cubic (C) effects were found to be statistically significant (p < 0.05). Although the use of FSM at a 2.5% level provided FI similar to the control group, its use at a 10.0% level reduced FI. The adverse effects of increasing FSM levels on FI became particularly evident on Day 14. However, this effect was not statistically significant in subsequent days.

TABLE 2.

Effect of fig seed meal supplement in compound feeds on feed intake (FI) of broiler quails (g/quail).

	Fig seed meal, %						Effects
Age (days)	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
7	37.08	37.77	35.42	33.35	0.88	0.296	NS	NS	NS
14	132.72a	128.59ab	122.38ab	113.69b	2.45	0.029	*	*	*
21	273.50	269.86	257.28	260.04	3.63	0.342	NS	NS	NS
28	463.37	459.66	453.83	448.83	4.70	0.722	NS	NS	NS
35	693.60	704.38	676.99	673.51	7.58	0.449	NS	NS	NS

Note: Means within the same row marked with different superscript letters (a, b) are statistically different from each other (p < 0.05).

Abbreviations: C, cubic; FSM, fig seed meal; L, linear; NS, not significant; Q, quadratic; SEM, standard error of the mean.

^* p < 0.05.

Table 3 evaluates the effects of diets containing different FSM levels on BW gain (BWG). The data showed a significant decrease in BWG with increasing FSM levels on Days 7, 14 and 35 (p < 0.05). On Day 7, although the control group had the highest BWG measurement (26.54 g), the FSM‐10.0 group showed the lowest measurement at 20.01 g (p < 0.05). Similarly, the BWG level of the FSM‐10.0 group remained at the lowest level on Days 14 and 35 (p < 0.05).

TABLE 3.

The effect of fig seed meal supplement in complete diets on the body weight gain (BWG) of broiler quails (g/quail).

	Fig seed meal, %						Effects
Age (days)	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
7	26.54a	24.41ab	21.72ab	20.01b	0.73	0.005	*	*	*
14	49.11a	46.79a	43.63ab	39.60b	1.04	0.005	*	*	*
21	85.31	84.90	77.35	78.87	1.59	0.172	NS	NS	NS
28	135.32	138.12	162.04	135.56	8.89	0.679	NS	NS	NS
35	204.14a	196.29ab	183.79ab	175.69b	3.40	0.010	*	*	*

Note: Means within the same row marked with different superscript letters (a, b) are statistically different from each other (p < 0.05).

Abbreviations: C, cubic; FSM, fig seed meal; L, linear; NS, not significant; Q, quadratic; SEM, standard error of the mean.

^* p < 0.05.

In contrast, no significant difference was detected between groups regarding BWG on Days 21 and 28 (p > 0.05). Although a decreasing trend was observed in the FSM‐5.0 and FSM‐10.0 groups on certain days, this effect was not found to be continuous.

Table 4 examines the FCR of quails fed with rations containing different levels of FSM. During the trial period, it was determined that the FCR numerical value in the FSM‐10.0 group was significantly higher compared to the control group on Days 7, 14 and 35 (p < 0.05). It shows that the FSM‐10.0 level negatively affects feed efficiency. Similarly, higher FCR values were observed in the FSM‐5.0 group compared to the control group on Days 7 and 35. No statistically significant differences were detected between groups on Days 21 and 28 (p > 0.05). The findings obtained demonstrate that increasing FSM levels had linear, quadratic and cubic effects on the FCR. The linear and quadratic effects were found to be statistically significant on Days 7, 14 and 35 (Table 4).

TABLE 4.

Effect of fig seed meal in compound feed on feed conversion ratio (FCR) of broiler quails (g/quail).

	Fig seed meal, %						Effects
Age (days)	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
7	1.41a	1.55ab	1.64b	1.66b	0.03	0.000	*	*	*
14	2.72a	2.75ab	2.80ab	2.88b	0.02	0.022	*	*	*
21	3.21	3.20	3.33	3.33	0.03	0.359	NS	NS	NS
28	3.44	3.37	3.32	3.37	0.08	0.964	NS	NS	NS
35	3.43a	3.60ab	3.68ab	3.86b	0.05	0.007	*	*	*

Note: Means within the same row marked with different superscript letters (a, b) are statistically different from each other (p < 0.05).

Abbreviations: C, cubic; FSM, fig seed meal; L, linear; NS, not significant; Q, quadratic; SEM, standard error of the mean.

^* p < 0.05.

The effects of diets containing FSM on the relative carcass and internal organ weights of female broiler quails are presented in Table 5. Regarding carcass parameters, the thigh and back ratios were significantly higher in the FSM‐5.0 group compared to the control group (p < 0.05). A cubic effect was also observed for the wing ratio (p < 0.05). However, no statistically significant differences were detected among the groups in terms of carcass yield, breast, neck and CW (p > 0.05). Although changes in CW were not statistically significant, lower mean measurements were recorded in the FSM‐2.5 and FSM‐10.0 groups. Regarding internal organ parameters, a decreasing trend in total intestinal weight was observed in the FSM‐2.5 and FSM‐10.0 groups compared to the control, but this difference was not statistically significant (p > 0.05). Furthermore, no statistically significant differences were found among the groups for heart, spleen, liver, gizzard and proventriculus weights (p > 0.05).

TABLE 5.

The effect of fig seed meal supplement in compound feed on the relative carcass (g/100 carcass weight [CW]) and internal organ (g/100 g body weight [BW]) weights of female broiler quails.

	Carcass parameters of female quails
	Fig seed meal, %						Effects
	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
Carcass yield	62.28	60.48	58.20	58.30	0.61	0.054	NS	NS	NS
Breast	41.88	39.70	40.78	40.34	0.48	0.464	NS	NS	NS
Thigh	22.06b	24.00ab	24.10a	23.76ab	0.30	0.036	*	*	*
Wing	8.06ab	8.38a	7.04b	7.48ab	0.19	0.043	NS	NS	*
Neck	6.04	4.96	4.96	5.10	0.20	0.151	NS	NS	NS
Back	19.90b	21.08ab	23.16a	22.20ab	0.44	0.039	*	*	*
Carcass weight	122.79	110.60	115.84	116.86	2.74	0.513	NS	NS	NS

	Internal organ parameters of female quails
	Fig seed meal, %						Effects
	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
Heart	0.94	0.96	0.92	1.04	0.03	0.550	NS	NS	NS
Spleen	0.08	0.08	0.04	0.06	0.01	0.547	NS	NS	NS
Liver	2.48	2.48	2.88	2.34	0.16	0.408	NS	NS	NS
Total intestine	6.04	4.22	5.04	4.38	0.30	0.139	NS	NS	NS
Gizzard	3.02	2.66	2.68	2.44	0.08	0.076	NS	NS	NS
Proventriculus	0.50	0.42	0.48	0.44	0.02	0.424	NS	NS	NS

Note: Means within the same row marked with different superscript letters (a, b) are statistically different from each other (p < 0.05).

Abbreviations: C, cubic; FSM, fig seed meal; L, linear; NS, not significant; Q, quadratic; SEM, standard error of the mean.

^* p < 0.05.

The effects of diets containing FSM on the relative carcass and internal organ weights of male broiler quails are presented in Table 6.

TABLE 6.

The effect of fig seed meal (FSM) supplement in compound feed on the relative carcass (g/100 carcass weight [CW]) and internal organ (g/100 body weight [BW]) weights of male broiler quails.

	Carcass parameters of male quail
	Fig seed meal, %						Effects
	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
Carcass yield	63.16a	62.20ab	59.72b	61.18ab	0.45	0.032	*	*	*
Breast	41.06	41.68	38.80	39.22	0.45	0.051	*	NS	NS
Thigh	22.80	22.92	24.10	24.12	0.31	0.263	NS	NS	NS
Wing	7.20	7.02	8.64	7.12	0.27	0.108	NS	NS	NS
Neck	5.34	5.34	4.76	4.52	0.20	0.367	NS	NS	NS
Back	21.52	21.70	22.54	24.22	0.63	0.442	NS	NS	NS
Carcass weight	113.97	118.47	110.96	106.01	1.84	0.096	NS	NS	NS

	Male quail internal organ parameters
	Fig seed meal, %						Effects
	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
Heart	1.00	1.02	1.00	1.22	0.04	0.205	NS	NS	NS
Spleen	0.08	0.02	0.08	0.04	0.01	0.155	NS	NS	NS
Liver	2.14	1.86	1.82	1.82	0.08	0.438	NS	NS	NS
Total intestine	4.72a	3.84ab	3.44b	3.34b	0.16	0.004	*	*	*
Gizzard	2.48	2.36	2.46	2.50	0.09	0.953	NS	NS	NS
Proventriculus	0.38	0.38	0.38	0.46	0.02	0.501	NS	NS	NS

Note: Means within the same row marked with different superscript letters (a, b) are statistically different from each other (p < 0.05).

Abbreviations: C, cubic; FSM, fig seed meal; L, linear; NS, not significant; Q, quadratic; SEM, standard error of the mean.

^* p < 0.05.

Regarding carcass parameters, the carcass yield in the FSM‐5.0 group was significantly lower compared to the control group (p < 0.05). Additionally, a trend of decreasing breast ratio was observed with increasing FSM levels, although this difference was marginally significant (p = 0.051). No significant differences were detected among the groups in terms of thigh, wing, neck and back ratios or CW (p > 0.05). Regarding internal organ parameters, total intestinal weight was significantly lower in the FSM‐5.0 and FSM‐10.0 groups compared to the control group (p < 0.05). However, no statistically significant differences were found among the groups for heart, spleen, liver, gizzard and proventriculus weights (p > 0.05).

The levels of TAS, TOS, OSI, AST, ALP, Glu, TP, albumin, globulin and cholesterol in female and male quails fed diets containing FSM are demonstrated in Table 7. In female quails, the TAS levels of those fed with 10.0% FSM were significantly lower compared to the control group (p < 0.05). No significant differences among the trial groups were observed in TOS, OSI, AST, ALP, Glu, TP and albumin levels (p > 0.05). The highest globulin and cholesterol levels were observed in the group fed 5.0% FSM, and significant differences were found between this group and the control group for both parameters (p < 0.05). In female quails fed with 10.0% FSM, the TOS levels were significantly lower compared to the control and FSM‐2.5% groups. At the same time, the OSI values were significantly reduced in the FSM‐5.0% and FSM‐10.0% groups compared to the control group (p < 0.05). No significant differences were found in male quails in TAS, AST, ALP, TP, albumin, globulin and cholesterol levels among the trial groups (p > 0.05). The highest Glu levels were found in the FSM‐5.0% group, and significant differences were observed between this group and the FSM‐2.5% and FSM‐10.0% groups (p < 0.05).

TABLE 7.

The levels of total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), aspartate aminotransferase (AST), alkaline phosphatase (ALP), glucose, total protein, albumin, globulin and cholesterol in female and male quails.

	Female quail
	Fig seed meal, %						Effects
	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
TAS (mmol/L)	1.45a	1.37ab	1.34ab	1.28b	0.02	0.036	*	*	*
TOS (mmol/L)	5.07	4.18	3.71	6.04	0.36	0.088	NS	NS	NS
OSİ (%)	0.35	0.30	0.27	0.48	0.03	0.063	NS	*	NS
AST (U/L)	165.40	158.80	174.20	175.80	8.50	0.901	NS	NS	NS
ALP (U/L)	526.20	433.60	620.40	535.00	29.50	0.167	NS	NS	NS
Glucose (mg/dL)	247.40	198.80	202.20	222.60	13.54	0.597	NS	NS	NS
T protein (g/dL)	17.32	20.72	26.36	19.90	1.28	0.067	NS	NS	NS
Albumin (g/dL)	5.80	7.24	8.50	5.58	0.55	0.212	NS	NS	NS
Cholesterol (mg/dL)	128.20b	162.80ab	200.40a	174.80ab	9.00	0.024	*	*	*

	Male quail
	Fig seed meal, %						Effects
	Control‐0.00	FSM‐2.50	FSM‐5.00	FSM‐10.00	SEM	p	L	Q	C
TAS (mmol/L)	1.08	1.29	1.33	1.29	0.04	0.096	NS	*	NS
TOS (mmol/L)	8.64a	8.94a	5.74ab	4.18b	0.60	0.002	*	*	*
OSİ (%)	0.89a	0.64ab	0.43b	0.31b	0.07	0.012	*	*	*
AST (U/L)	170.80	160.40	162.20	204.80	8.12	0.182	NS	NS	NS
ALP (U/L)	546.60	486.20	607.40	549.00	36.19	0.738	NS	NS	NS
Glucose (mg/dL)	260.20ab	231.80b	291.40a	229.00b	8.32	0.012	NS	NS	*
T protein (g/dL)	17.46	15.28	14.04	15.56	0.77	0.494	NS	NS	NS
Albumin (g/dL)	4.78	4.86	4.78	5.74	0.29	0.611	NS	NS	NS
Cholesterol (mg/dL)	142.00	127.60	129.40	155.20	7.37	0.553	NS	NS	NS

Note: Means within the same row marked with different superscript letters (a, b) are statistically different from each other (p < 0.05).

Abbreviations: C, cubic; FSM, fig seed meal; L, linear; NS, not significant; Q, quadratic; SEM, standard error of the mean.

^* p < 0.05.

4. Discussion

This study examines the effects of FSM supplemented at different ratios in the diet on growth performance, carcass characteristics, oxidant–antioxidant balance and specific biochemical blood parameters. In the present study, FSM added to feeds at various ratios did not cause any statistical differences in FI of quails on Days 7, 21, 28 and 35; however, numerical decreases were observed in the FSM 10% group. On Day 14 of the study, FI decreased in a dose‐dependent manner (p < 0.05); however, no differences were observed in subsequent measurements (p > 0.05; Table 2). Although the use of FSM at a 2.5% level provided FI similar to the control group, its use at a 10.0% level decreased FI. These findings suggest that high levels of FSM supplementation may restrict FI due to components such as phenolic compounds in its content (Tufan et al. 2023). However, because there is no other finding on FSM in poultry, new research is needed on the main factor that limits feed consumption. In a study conducted by Bulbul et al. (2016) on the use of safflower meal in the diet as an alternative to soybean meal as a different protein source, it was reported that the addition of up to 30% (15%–15%) safflower–sunflower meal did not have a negative effect on performance parameters in quails. Tufan et al. (2023) reported that when fig seed was used as a feed additive, adding 0.25% fig seed resulted in higher FI than other groups. In their study, Tuzun et al. (2021) reported an increase in FI on Days 29 and 112 when sunflower meal was used as an alternative to soybean meal. However, when comparing groups in their study, they did not report significant differences in BWG and FCR (Tuzun et al. 2021). In a study by Rama Rao et al. (2006), broiler chickens fed with sunflower meal instead of soybean meal showed higher FI in the sunflower meal‐fed groups on Days 21 and 42.

In the present study, FSM used at different ratios in quail nutrition had significant linear, quadratic and cubic effects on BWG (p < 0.05). When comparing the experimental groups that were fed FSM with the control group, although dietary inclusion of up to 5% did not cause any changes, the group supplemented with 10% FSM showed a decrease in BWG (Table 3). These data indicate that high levels of FSM supplementation may adversely affect BWG (Table 3). As no studies on the use of FSM were found in the literature review, the results were evaluated by comparing them with studies conducted using alternative feed ingredients.

The study results showed that FSM supplementation in feed resulted in linear, quadratic and cubic differences in FCR on Days 7, 14 and 35 in a dose‐dependent manner (p < 0.05; Table 4), whereas no differences were detected on Days 21 and 28 (p > 0.05). In the present study, when compared to the control group, no differences were observed in groups receiving 2.5% and 5% FSM supplementation, whereas the group receiving 10% supplementation showed a decrease in FCR. The decrease in FCR when FSM was administered at a 10% level may be related to the fibre content in FSM. In conclusion, supplementation with FSM up to 10.0% may negatively affect FCR, and higher inclusion levels, in particular, may impair overall feed utilization. Tuzun et al. (2021) similarly reported an increase in the FCR in their study investigating sunflower meal as an alternative to soybean meal. Rama Rao et al. (2006), in a study replacing soybean meal with sunflower meal, reported no significant difference in FCR on Day 21; however, a reduction was observed over the entire experimental period. In their research, Alagawany et al. (2017) reported that sunflower meal up to 50% instead of soybean meal increased FCR and BWG while decreasing FI. Alagawany et al. (2017) reported that adding sunflower meal to feed at rates higher than 50% instead of soybean meal reduced the FCR. In this respect, it shows similarity with our current study. In female quails, the highest thigh and back weights among carcass parameters were obtained in groups receiving 5% FSM (p < 0.05; Table 5). No differences were found in carcass yield, breast, wing, neck and CW (p > 0.05; Table 5). Compared to the control group, using FSM in the diet of up to 5% did not lead to any adverse effects (Table 5). Compared to the control group, no differences were detected in internal organ weights in female quails supplemented with FSM in their diet (p > 0.05; Table 5). These results indicate that using FSM up to FSM‐5.0 level may positively affect specific carcass parameters in quails; however, high‐level usage may lead to potential adverse effects, particularly on carcass yield and intestinal weight. Additionally, it can be stated that FSM did not produce any significant effect in terms of internal organ weights. In male quails, although carcass yield among carcass parameters was affected by FSM (p < 0.05), breast, thigh, wing, neck, back and CW were not affected (p > 0.05). Carcass yield was lower in both FSM‐10.0 and FSM‐5.0 groups than in the control group, and a decreasing trend was observed in the breast ratio. No significant differences between groups in other carcass and internal organ parameters were found. Total intestinal weight was lower in the FSM‐5.0 and FSM‐10.0 groups compared to the control group. These findings indicate that using FSM up to 5% level may decrease carcass yield and total intestinal weight in male quails. However, it has no significant effect on other parameters of internal organs. Additionally, it should be considered that high‐level usage of FSM may adversely affect carcass yield. Rama Rao et al. (2006) reported no differences in liver, abdominal fat, intestine length and total internal organ weights in their study. Rama Rao et al. (2006) reported that sunflower meal increased gizzard weight. However, in the present study, no differences were detected in gizzard weight. In their study, Tufan et al. (2023) reported positive effects on carcass parameters and internal organ weights when using fig seeds as an additive. Salari et al. (2009) investigated the effects of varying full‐fat sunflower seeds (0, 70, 140 and 210 g/kg) on broiler performance and carcass traits. Their results indicated that dietary treatments had no significant effect on the percentages of breast, thigh, digestive system or gizzard weights. However, the relative liver weight decreased significantly (p < 0.05), whereas the reduction in abdominal fat was not statistically significant. In the present study, among internal organ weights in female and male quails, only total intestinal weight (p < 0.05) was found to be different in male quails when fed FSM. FSM supplementation did not affect other internal organ weights (p > 0.05; Tables 5 and 6). Tufan et al. (2023) reported differences in female quail internal organ weights in their study. At the same time, the present study utilized FSM; Tufan et al. (2023) used whole fig seeds. These differences are thought to be due to the variations in the fat content of whole fig seeds versus the fibre content in FSM. Alagawany et al. (2017) reported that sunflower seed meal usage did not create any differences in internal organ weights. Similarly, although carcass characteristics did not show statistically significant changes in this study (p > 0.05), heart percentage was found to decrease significantly with increasing FSM levels (p < 0.01). It was concluded that there were some interactions with high levels of FSM usage, but it did not significantly alter carcass characteristics. Rama Rao et al. (2006) reported that low doses of sunflower meal affected internal organ weights, whereas high doses caused a decrease in internal organ weights. The adverse effects of high‐dose FSM on carcass characteristics may be due to the effects of high fibre content on the digestive system during the early growth period. Evaluating biochemical parameters in scientific research provides important information about changes in metabolic profiles. In the literature review, as studies investigating the effects of figs and their products on serum biochemical parameters and antioxidant status in quails are limited, the study's results were interpreted in light of similar studies. Maintaining balance between the body's oxidant substances and antioxidant systems is important for preserving cell and tissue integrity. The total effect of all substances showing antioxidant properties is demonstrated by TAS measurement (Erel 2004; Tufan et al. 2023). In this study, TAS values decreased numerically (p > 0.05) in the 2.5% and 5% groups compared to the control group in female quails. TAS levels decreased significantly (p < 0.05) in the group supplemented with 10.0% FSM. Additionally, no significant difference was detected in TAS levels of male quails across all experimental groups (p > 0.05). Exposure to stress during early life development can have long‐term consequences on various biological functions, including oxidative stress. In a study examining TAS, TOS and resistance against free radical attack in quails exposed to sudden stress before hatching, after hatching or during both periods, as well as those not exposed to any stress factors, it was reported that TAS levels decreased over time in all females under stressful conditions during the reproductive period (Zimmer and Spencer 2015). In the present study, the significant decrease in TAS values in female quails supplemented with 10.0% FSM compared to the control group, and the absence of this condition in male quails across all experimental groups, can be associated with stress during the reproductive period (35–42 days) in female quails (Zimmer and Spencer 2015). Additionally, the numerical increase in TOS and OSI levels in the female FSM‐10.0 group compared to other groups supports this finding. Cholesterol is a precursor for bile acid synthesis and serves as a substrate for steroid hormone synthesis (such as oestrogen and androgen) (Chen et al. 2008). Esterified cholesterol is typically found in serum. Asadi et al. (2006) concluded that F. carica L. leaf extract could be beneficial in modulating triglyceride and cholesterol release from poultry liver. In a study investigating the effects of fig fruit and leaves on hyperglycaemia in alloxan‐induced diabetic rats, cholesterol levels were determined to be 95.84 mg/dL in the control group. In comparison, they were 214.27 mg/dL in the 5% F. carica L. group and 179.45 mg/dL in the 10% F. carica L. group (p < 0.05) (El‐Shobaki et al. 2010). Consistent with El‐Shobaki et al.’s (2010) findings, in this study, although cholesterol levels in female quails of the control group were 128.2 mg/dL, they increased to 200.40 mg/dL in the FSM 5.0 group (p < 0.05). This condition is thought to be of hepatic origin. Oxidative stress is a pathological process due to the oxidant/antioxidant balance shift in favour of oxidants. The total value of oxidative stress is expressed as TOS. In a study investigating the effect of fig seed supplementation as a feed additive in quail diets on oxidant/antioxidant balance parameters, TOS levels in male quails were determined to be 17.64 µmol/L in the control group. In comparison, they were 13.19 µmol/L in the 0.25% group and 11.94 µmol/L in the 0.50% group (p > 0.05) (Tufan et al. 2023). In this study, TOS levels in male quails of the control group were determined to be 8.64 µmol/L and decreased significantly (p < 0.05) to 4.19 µmol/L in the 10% group. In a study where phenolic compounds were extracted from industrial by‐products—cold‐pressed fig seed and black cumin pomace—under suitable extraction conditions, both fig seed and black cumin pomace were found to contain vanillic acid, gentisic acid, protocatechualdehyde, vanillin and ferulic acid. The same study concluded that the antioxidative potential of fig seed and black cumin extracts was attributed to their main phenolic compounds (Kök 2020). In this study, the decrease in TOS levels in male quails of the 10% group is thought to be related to the antioxidative effect of phenolic compounds present in FSM. Studies El‐Shobaki et al. (2010) and Stephen Irudayaraj et al. (2017) have indicated that figs and fig products may aid in treating hyperglycaemia. Tufan et al. (2023) found that fig seed supplementation generally reduced blood Glu levels in quail. In this study, Glu levels numerically decreased in male quail in other groups (2.5% and 10%), except for those in the 5% group (p > 0.05). This effect may be related to the modulation of Glu transport by flavonoids through relevant intestinal transporters (Song et al. 2002).

5. Conclusions

In conclusion, FSM used at different ratios as a replacement for sunflower meal did not adversely affect performance parameters up to the 5% inclusion level. However, performance parameters were negatively affected at levels exceeding 5%. When evaluated considering the sex factor, it was determined that the use of FSM up to 5% had no adverse effects on serum parameters and oxidant/antioxidant balance. These findings provide an important scientific basis for determining the safe usage limits of FSM in poultry rations and contribute to its evaluation as a potential feed ingredient.

Author Contributions

Mehmet Irmak, Tuncay Tufan and Muzaffer Denli designed the study. Mehmet Irmak, Hasan Hüseyin Ipçak and Veysi Kayri experimented and analysed the serum samples. Kıvanç Irak, Nurhan Şahin, Özgür Yaşar Çelik and Cahit Özcan helped in writing and editing the manuscript. Mehmet Irmak and Muzaffer Denli performed the statistical analyses. All authors interpreted the data, critically reviewed the manuscript for significant intellectual content and approved the final version.

Ethics Statement

The Animal Research Centre conducted this work in compliance with the Animal Experiments Directive, which was approved by the Ethics Committee (Date: 05.11.2024, No: 2024/33).

Consent

The authors have nothing to report.

Conflicts of Interest

The authors declare no conflicts of interest.

Irmak, M. , Denli M., Şahin N., et al. 2025. “Use of Fig Seed Meal as a New Alternative Feed Source in Quails: Effect on Growth Performance, Carcass Characteristics, Antioxidant Capacity and Serum Biochemistry.” Veterinary Medicine and Science 11, no. 5: 11, e70533. 10.1002/vms3.70533

Data Availability Statement

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