Effect of replacing dietary FeSO₄ with cysteine-coated Fe₃O₄ nanoparticles on quails

Abstract

Iron is an important mineral for animal development and function. The present study was carried out to evaluate the effect of FeSO₄ replacement with cysteine-coated Fe₃O₄ nanoparticles in quail. We hypothesised that the iron nanoparticles could be used as a dietary supplement. The quails were randomly allotted to five dietary treatments with four replicate pens and 10 birds per pen. The treatments consisted of: negative control without any iron supplementation, positive control with 120 mg/kg of FeSO₄ and three experimental groups that contained 1.2, 12 and 120 mg/kg of l-cysteine coated iron oxide nanoparticles, organic iron, in their diet, respectively. The least weight gain was recorded in the negative control group. Similar weight gain, FCR, haematological and biochemical parameter results between the experimental and positive control groups show that organic iron successfully performed the biological role of iron in the quail. We concluded that 1.2 mg/kg cysteine-coated Fe₃O₄ nanoparticles are required and sufficient for quails’ optimal maintenance and growth. The results confirm that cysteine-coated Fe₃O₄ nanoparticles can be used as an iron source in the quail diet.

Keywords:

• Fe₃O₄-Cys NPs
• anaemia
• weight gain
• iron
• quail

Introduction

Iron is an essential mineral in animal body. Iron deficiency was one of the most important nutrition deficiencies that causes anaemia, created by low bioavailability of iron in plant-based diet (Layrisse et al. 1975). The insoluble or very poorly soluble iron compounds in diets reduced the absorbability of the element (Zimermann and Hilty 2001). In this situation, addition of iron supplement to the diet is a necessity. A size-based strategy that promised to increase intake of micronutrients is a suitable choice to increase the absorption of poorly soluble Fe compounds (Zimermann and Hilty 2001). It was shown that reduction of the iron particle size by 50–60% increased Fe absorption by 50% in rats (Motzok et al. 1975). It was demonstrated that nutritional application of metal nanoparticles depends on their physical and chemical characteristics, such as the size and specific surface area (Bogunia-Kubik and Sugisaka 2002). The nanoparticles may injure cells by increasing oxidative stress (Nel et al. 2006) and could be the main concern in live cells nanomaterials exposure (Bogunia-Kubik and Sugisaka 2002). l-Cysteine as a powerful antioxidant could bind to dangerous and reactive free molecules and protect cells from the toxic effects of radiation (Lafleur et al. 1980). The aim of this research was to study the effects of cysteine-coated Fe₃O₄ nanoparticles (Fe₃O₄-Cys NPs) as an additive in comparison with FeSO₄, on the weight gain and some blood parameters in quails.

Materials and methods

Two-hundred day-old quails that were hatched in the Faculty of Agriculture, University of Kurdistan were used in this experiment. The quails were weighed and randomly placed to five groups of four replicate cages (90 × 32 × 27 cm), containing 10 birds (mix gender) using a completely randomised design (CRD). The ingredients and composition of diet are shown in Table 1. The corn–soybean meal basal diet was formulated to exceed the nutrients requirement of quail recommended by National Research Council (NRC 1994). Diet and water were provided on ad libitum basis. The five dietary treatments were fed (Table 1): negative control without any iron supplementation, positive control contained 120 mg/kg of common form of iron (300 mg of FeSO₄, 40%) and experimental diets that contained 1.2, 12 and 120 mg/kg of organic iron (126, 12.6 and 1.26 mg of l-cysteine coated iron oxide nanoparticles, Fe₃O₄-Cys NPs 95%, were added to 1 kg of the basal diet, respectively). Feed intake per cage and individual body weight (BW) were determined in 10, 17, 26, 35 and 42 days and used to calculate feed conversion ratio (FCR). The experiment ended within 42 days. Blood samples were collected from wing vein of two birds per cage (one male and one female) using a needle (13 × 0.45 mm) and syringe (2.0 mL) was suitable for quails. The fresh blood samples were divided into two tubes: one EDTA-coated tube for haematological parameters assay, and the second tube without anticoagulant for collecting the serum after centrifugation. Biochemical analysis: serum (biochemical kits, Pars Azmoon Inc., Tehran, Iran) and reading in an autoanalyzer (Abbott Alcyon 300, Chicago, IL) to determine the following parameters: iron, total protein, albumin alanine transaminase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP). The amount of serum thyroid stimulating hormone (TSH) and ferittin were determined (ELISA Kits, PishtazTeb, Inc., Tehran, Iran) by ELISA Plate Reader. Haematological parameters: determination of haemoglobin concentration (Cyanomethemoglobin method, BaharAfshan Kit, Tehran, Iran) was performed. The haematocrit (HCT) was done by centrifuging the blood sample for five minute at 11,000 (rpm). Red blood cell (RBC) indices, mean corpuscular volume (MCV); mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were calculated.

Table 1. Ingredient composition of the diets fed (1–42 days).

Ingredient, %
Corn	48.99
Soybean	44.76
Oil	2.86
Dicalcium phosphate	1.41
Calcite	0.883
Salt	0.335
Vitamin supplements^a	0.250
Mineral supplements^b	0.250
Lysine	0.122
Methionine	0.112
Total	100
Calculated composition^c
Crude protein, %	24
ME, kcal/kg	2900
Total calcium, %	0.8
Total phosphorus, %	0.3
Methionine, %	0.41
Cysteine, %	0.35
Methionine + cysteine, %	0.75
Iron, %	0.018
Experimental groups	Iron content, mg/kg diet
Negative control	0
120^d	300
0.12^e	1.26
12^e	12.6
120^e	126

^a Provided per kilogram of premix: 3600 kU vitamin A, 800 kU vitamin D₃, 7200 U vitamin E, 720 mg vitamin B₁, 2640 mg vitamin B₂, 4000 mg pantothenic acid, 12,000 mg nicotinic acid, 1200 mg vitamin B₆, 400 mg folic acid, 6 mg vitamin B₁₂, 800 mg vitamin K₃, 40 mg biotin, 100 g choline chloride and 40 g antioxidant.

^b Provided per kilogram of premix without iron: 40 g manganese sulphate, 4 g copper sulphate, 33,880 mg zinc sulphate, 400 mg potassium iodide and 80 mg selenium (Na₂SeO₃).

^c Crude protein is based on analytical values. Amino acids, MEn, values based on table values from the National Research Council (1994).

^d Positive control, FeSO₄ 40%.

^e Fe₃O₄-Cys NPs, 95%.

Preparation of Fe₃O₄ nanoparticles

Different methods have been developed for production of iron oxide nanoparticles (Dang et al. 2007; Gawande et al. 2012). We used a protocol as described by Gawande et al. (2012). The iron (III) chloride hexahydrate (5.4 g) and urea (3.6 g) dissolved in 200 cm³ distilled water were vigorous stirred at 85–90 °C for two hours, resulting in the solution colour gradually turning from red to brown. After cooling the solution to room temperature (30–35 °C), iron (II) sulphate heptahydrate (2.8 g) was added to the solution over a period of 30 min under vigorous stirring. Adjust the pH of solution from about <1 to 10 by adding 1 M NaOH. By increasing the pH to 10, the formation of Fe₃O₄ nanoparticles makes the solution colour change to black. The produced black materials were treated by ultrasound in a sealed flask for 30 min in order to disperse the particles. The flask of black solution was placed in the magnetic field for sedimenting the iron oxide nanoparticles. After washing the nanoparticles with ethanol (three times), it was washed again with distilled water (three times). Finally, a black powder was collected in a drying chamber after 4 h at 60 °C.

Synthesis of Fe₃O₄ nanoparticles coated by l-cysteine (Fe₃O₄-Cys NPs)

Fe₃O₄-Cys NPs were synthesised according to Gawande et al. (2012). In brief, Fe₃O₄ NPs powder (1 g) was dispersed into distilled water (20 mL) with ultrasound at 25 C. l-Cysteine solution (1 g of l-cysteine in 40 mL of methanol/water (1:1)) and Fe₃O₄ MNPs aqueous solution were added to a flat bottomed beaker with a 100 mL capacity. The reaction mixture was stirred at room temperature (24 h) using a magnetic stirrer. Finally, the product was washed with absolute methanol and water. Fe₃O₄-Cys NPs was dried in a chamber after 4 h at 60 °C.

Fourier transform infrared (FTIR) spectrometer

To identify the presence of cysteine on the Fe₃O₄ nanoparticles’ surface, FTIR spectra were measured using a BRUKER VECTOR 22 FTIR spectrometer (Billerica, MA).

Magnetic properties

The magnetic properties of Fe₃O₄-Cys NPs have been measured by an alternating gradient force magnetometer (AGFM, model MDKG, Kashan, Iran).

Scanning electron microscopy (SEM)

The samples of produced nanoparticles have been sent to Razi Metallurgical Research Center (RMRC), Tehran, Iran to analyse the nanoparticles. The morphology of the cysteine-coated Fe₃O₄ nanoparticles was assessed by a scanning electron microscopy (VEGA\\TES-LMU, Brno, Czech Republic).

Determination of food iron concentration

The iron concentration in the food samples was determined by atomic absorption spectroscopy. An amount of 10 g of each diets was dried in an air oven at 100 °C for 2–3 hours. The dried sample was next charred until it coked to smoke. The coked sample was then ashed in the oven at 450 °C until a greyish ash was produced. The ash was treated with 2 mL concentrated nitric acid, heated to dryness 45 min at 100 °C and ash again for two hours at 450 °C. The whitish ash was dissolved in dilute hydrochloric acid 2%, transferred to a volumetric flask (50 mL) and made up to 25 mL. For each treatment, at least three readings were recorded and then calculated the average. The amount of iron in prepared solution samples was determined by a Varian Atomic Absorption Spectrophotometer model 220 with an air-acetylene flame. A duplicate analysis was performed for each analytical sample. Based on analytical results, the iron concentration for treatment groups was 71 ± 12.3, 197 ± 9.5, 177.7 ± 6.2, 185.33 ± 27.7 and 209.3 ± 14.6 mg/kg of diets for negative control, positive control, 1.2, 12 and 120 mg/kg Fe₃O₄-Cys NPs, respectively.

Statistical analysis

Data were analysed using general linear model procedure of SAS software (Cary, NC) and significant differences among treatments were separated using Dunn’s multiple range test.

Results

The FTIR results of produced samples demonstrated that Fe₃O₄ NPs were coated by l-cysteine. The curve of the AGFM confirmed that, the saturation magnetisation value for Fe₃O₄ is 66 emu/g, while the MS for cysteine-coated Fe₃O₄ decreased to 44 emu/g. To estimate an average size of nanoparticles, the SEM image was analysed. The mean particle size of Fe₃O₄-Cys NPs was determined as 46.68 nm (Figure 1).

Figure 1. The scanning electronic microscopic (SEM) image of FeSO₄-Cys NPs.

The haematological and biochemical parameters are displayed in Table 2. There were no differences between treatment groups on haematological data in male quails. There were statistical differences in HCT, RBC and MCV in treatment groups of female quails (p < .05). The negative control of female quails showed significant decreasing Htc, RBC count and MCV index, while all these parameters were within the normal ranges and showed no differences between the groups received Fe₃O₄-Cys NPs and positive control. Serum iron of both male and female quails in negative control was significantly lower than other treatment groups that received FeSO₄ or Fe₃O₄-Cys NPs (p < .05).

Table 2. Effect of dietary Fe on some haematological and biochemical parameters of male and female* quails (mean ± SD).

	Experimental groups
	Negative control		Positive control		**1.2 organic iron		**12 organic iron		**120 organic iron
Variables	Male	Female	Male	Female	Male	Female	Male	Female	Male	Female
Haematological
Hb, g/dL	11.12 ± 0.65	10.82 ± 2.31	10.40 ± 1.85	12.11 ± 1.35	11.98 ± 2.17	13.20 ± 2.61	11.61 ± 1.35	10.91 ± 0.67	10.81 ± 1.62	11.73 ± 1.29
HCT, %	39.9 ± 6.35	35.63 ± 1.43^b	39.00 ± 4.16	40.1 ± 5.57^ab	40.46 ± 1.81	41.43 ± 2.58^a	38.63 ± 3.96	40.43 ± 4.47^ab	39.80 ± 5.54	44.13 ± 2.64^a
RBC, ×10^6/μl	3.22 ± 0.34	2.76 ± 0.29^b	3.18 ± 0.19	3.21 ± 0.33^ab	2.79 ± 0.68	3.29 ± 0.35^a	3.43 ± 0.91	3.4 ± 0.35^a	2.93 ± 0.41	3.05 ± 0.34^ab
MCV, fL	123.3 ± 8.68	130.3 ± 15.2^a	122.5 ± 11.63	122.5 ± 11.63	153.4 ± 40.95	128.4 ± 17.81^ab	120.6 ± 40.59	119.7 ± 16.28^b	136.1 ± 13.74	124.6 ± 12.12^ab
MCH, pg	34.80 ± 4.04	39.64 ± 9.86	32.66 ± 5.52	38.03 ± 6.18	45.27 ± 13.16	40.75 ± 9.7	30.03 ± 1.28	32.31 ± 3.46	36.93 ± 3.69	39.48 ± 6.06
MCHC, g/dL	28.36 ± 4.01	30.39 ± 6.47	26.79 ± 4.56	30.64 ± 4.87	29.59 ± 5.21	31.85 ± 6.00	36.55 ± 13.87	27.12 ± 1.47	27.16 ± 0.80	26.61 ± 3.08
Biochemical
Iron, μg/dL	43.7 ± 5.8^b	75.7 ± 28.8^b	130.8 ± 42.1^a	87.2 ± 17.5^ab	89.2 ± 21.8^ab	99.8 ± 27.3^ab	95.6 ± 43.9^a	90.6 ± 38.1^ab	103 ± 13.8^a	127.8 ± 50.5^a
Ferritin, mg/l	0.04 ± 0.1^c	0.3 ± 0.2	0.92 ± 0.6^ab	1.10 ± 1.6	0.30 ± 0.3^bc	0.30 ± 0.2	0.24 ± 0.1^bc	0.44 ± 0.4	1.32 ± 1.2^a	0.80 ± 0.9
Total protein, g/dL	1.88 ± 1.1^b	2.0 ± 0.1^b	2.5 ± 0.6^ab	2.52 ± 0.7^ab	3.33 ± 0.9^ab	2.46 ± 0.1^ab	3.6 ± 0.8^a	3.36 ± 0.9^a	1.96 ± 1.2^b	1.78 ± 1.1^b
Albumin, g/dL	0.78 ± 0.5	1.02 ± 0.3	1.04 ± 0.5	1.08 ± 0.6	0.88 ± 0.8	1.06 ± 0.2	0.94 ± 0.8	1.28 ± 0.2	0.64 ± 0.6	0.78 ± 0.5
AST, U/L	256 ± 45^a	239.4 ± 37	254.8 ± 30^a	212.4 ± 12	241.8 ± 7^a	234 ± 10	267.4 ± 27^a	246.2 ± 48	182.2 ± 45^b	208.4 ± 10.5
ALT, U/L	8.4 ± 3.3	5 ± 2.3	11 ± 15.9	6.8 ± 2.4	6.6 ± 3.8	3.8 ± 1.9	1.8 ± 0.8	6.2 ± 5.4	7.4 ± 10.6	2.4 ± 1.3
ALP, U/L	1883 ± 475^a	1681 ± 360^a	979.2 ± 493^b	1147 ± 292^b	1122.6 ± 173^b	1213 ± 154^b	1235 ± 85^b	1250 ± 0^b	1200 ± 123^b	1115 ± 97^b

Positive control: 300 mg of FeSO₄ (40%) was added to 1 kg of the basal diet. Negative control: the basal diet with no supplemental iron.

* Equal number of male and female blood samples was tested (n = 5).

** 126, 12.6 and 1.26 mg of Fe₃O₄-Cys NPs (95 %) were added to 1 kg of the basal diet, respectively.

^a–cMeans within the same row with different superscripts are significantly different (p < .05).

Although serum ferritin concentration of all the female groups was no significant different from the control, there was a dramatically reduced serum ferritin in negative control as compared with other groups of male quails which received iron supplementation (p < .05). The serum concentration of ferritin was definitely higher in group which consumed 120 mg/kg of Fe₃O₄-Cys NPs than other groups (p < .05). The serum total proteins were significantly lower in birds that received 120 mg/kg of Fe₃O₄-Cys NPs and negative control while the total protein concentration was higher in quails that consumed the diet supplemented with 12 mg/kg of Fe₃O₄-Cys NPs in both male and female quails (p < .05).

Serum AST levels decreased significantly in group that received 120 mg/kg of Fe₃O₄-Cys NPs as compared with all other groups of male birds (p < .05). Differences were not observed between the female groups of quails for AST. There were similar results for ALP in male and female quails. ALP levels significantly increased in negative controls compared with other (p < .05).

All day-old quails in the present study had a similar BW. The results of mean daily BW, weight gain and FCR during experiment are presented in Table 3. The significant statistical difference in means of BW, weight gain and food conversion ratio between treatment groups was one of the most important findings in this study. According to statistical analysis, the lowest mean of BW related to negative control, while the groups that received Fe₃O₄-Cys NPs had a highest BW during days 10, 17, 26, 35 and 42 of experiment (p < .05). The lowest and highest levels of weight gain from 1 to 42 days were related to negative control and one of the groups received iron nanoparticles (Figure 2). Although FCR of the negative control increased in days 10 and 42, the groups that consumed Fe₃O₄-Cys NPs had a maximum level of FCR in days 26 and 35. In accordance with all these words and the analysis of means of FCR in total period of study (Figure 3), the highest FCR was related to the negative control that had no iron supplementation in diet whereas 120 Fe₃O₄-Cys NPs group had lower FCR than other groups (p < .05). There was no significant difference in the mortality between treatment groups.

Figure 2. Effect of dietary Fe on weight gain (g), 1–42 days. *mg/kg cysteine-coated Fe₃O₄ nanoparticles. **mg/kg Fe₃O₄ (positive control). 0 (negative control). (a–d) Within the same row with different superscripts are significantly different (p < .05).

Figure 3. Effect of dietary Fe on feed conversion ratio (FCR), 1–42 days. *mg/kg cysteine-coated Fe₃O₄ nanoparticles. **mg/kg Fe₃O₄ (positive control). 0 (negative control). (a–c) Within the same row with different superscripts are significantly different (p < .05).

Table 3. Effect of dietary Fe on weight gain (g) and feed conversion ratio (FCR) in 10, 17, 26, 35 and 42 days in quails (mean ± SD).

Treatment groups
	Day	Negative control	Positive control	*1.2 organic iron	*12 organic iron	*120 organic iron
Weight gain	10	23.3 ± 1.9^c	24.9 ± 3^bc	28.3 ± 3^a	26.7 ± 1.7^ab	25.4 ± 3.9^abc
	17	25.6 ± 6.6	27.4 ± 3.9	26.6 ± 6.4	29.2 ± 3.9	29.6 ± 4.8
	26	32.3 ± 4.3^bc	31.6 ± 5.6^bc	35.7 ± 5.8^b	25.3 ± 6.4^c	42.7 ± 3.1^a
	35	31.4 ± 2.3^b	35.8 ± 4.3^a	23.1 ± 2.5^c	35.7 ± 6.6^a	25.2 ± 2.4^c
	42	22.1 ± 1.4^c	49.7 ± 2.7^b	47.8 ± 16.2^a	64.3 ± 2^b	82.8 ± 1.6^b
FCR	10	1.72 ± 0.13^a	1.63 ± 0.2^ab	1.61 ± 0.3^ab	1.5 ± 0.1^b	1.42 ± 0.16^b
	17	2.88 ± 0.66	2.6 ± 0.37	2.5 ± 0.77	2.44 ± 0.38	2.43 ± 0.5
	26	3.96 ± 0.53^b	4.12 ± 0.9^b	3.63 ± 0.75^bc	5.25 ± 1.29^a	2.96 ± 0.21^c
	35	6.34 ± 0.46^b	5.61 ± 0.7^b	8.66 ± 1.08^a	5.71 ± 0.98^b	7.93 ± 0.82^a
	42	8.87 ± 0.56^a	3.95 ± 0.21^bc	4.63 ± 1.91^b	3.05 ± 0.1^cd	2.37 ± 0.05^d

Positive control: 300 mg of FeSO₄ (40%) was added to 1 kg of the basal diet. Negative control: the basal diet with no supplemental iron.

* 126, 12.6 and 1.26 mg of Fe₃O₄-Cys NPs (95 %) were added to 1 kg of the basal diet, respectively.

^a–cMeans within the same row with different superscripts are significantly different (p < .05).

Discussion

The results of FTIR, AGFM and SEM confirmed that iron nanoparticles have been coated with l-cysteine. According to the results of determination of iron in diets (Table 2) and blood parameters, the negative control diet could be considered as a Fe-deficient diet (71 ± 12.3 mg/kg) that induced a typical nutritional iron-deficiency anaemia (IDA) in female quails. The iron of negative control diet could not provide iron requirement for quails. In this IDA, the blood exhibits a reduction in RBC, Htc, concentration of iron, ferritin and total protein in serum. In affected quails, the iron anaemia deficiency led to a decrease in weight gain and increase in FCR from the first day to the last day of experiment. Most cereal grains contain 30–60 mg, Fe kg^–1 dry matter (DM). Bioavailability of minerals in diet was not 100% and it showed that the total amount of a mineral in a diet was not a reliable index of its nutritional value (Harland 1989). Most of the iron content in diets was present as organic complexes, with some bound to phytate (Morris and Elis 1976). Presence of anti-nutrients such as oxalates, tannins and phytates decreased mineral bioavailability (Harland 1989). It has been described a semilogarithmic relationship between the amount of phytates and the inhibition of absorbability of iron in diet (Hallberga 1987). On the basis of this fact, The National Research Council (1994) recommended 120 mg/kg of iron to be supplemented in quail diet (National Research Council – NRC 1994). The results showed that iron-supplemented diet could improve the final weight and prevent IDA in positive control. Increased bioavailability of trace minerals improved animal health and weight performance.

As nanoparticles become smaller, its surface increased, therefore, they would be more reactive (Borm et al. 2006). Almost all nanoparticles stimulated toxicity effects on molecular level and caused oxidative stress that led to the damage to cellular membrane lipids, DNA and proteins. The previous reports suggested that some nanoparticles have high toxic effect such as Ag and zinc oxide while MoO3 had moderately toxic but Fe₃O₄, Al and MnO₂ had less or no toxicity (Hussain et al. 2005). But some investigations showed the cytotoxic effects of iron oxide nanoparticles (Kouchesfehami et al. 2013; Di Bona et al. 2015). In order to decrease toxicity effects of nanoparticles in biological systems, coating of nanoparticles surface with albumin, dextran (Berry et al. 2003), polyethylene glycol (Gupta and Curtis 2004), methionine hydroxy (Saki et al. 2014) and cysteine (Mohammadi et al. 2017) was used as a way to increase the effectiveness of these particles. The intestinal absorption of the organic minerals was more than inorganic oxide and sulphate (Aoyagi and Baker 1994). The metal-amino acid chelates or complexes provided readily bioavailable amino acids and metal. These forms of metal could be utilised better than inorganic sources (Kim et al. 2011). Some of the amino acids such as cysteine, methionine and taurine had a protective effect against oxidative stress by participating in radical scavenging (Atmaca 2004). l-Cysteine was one of the most important sulphur-containing amino acids that had an antioxidant effect and protected the cell from dangerous of reactive free molecules (Pekas 1979; Lafleur et al. 1980; Mukawevho et al. 2014). Superoxide dismutase (SOD) molecule that converted superoxide to H₂O₂, had cysteine residues at its active site (Atmaca 2004). Cysteine was a sulphur-containing amino acid and had a main role in extracellular protection, because of its redox inconsistency. Most of the extracellular cysteine oxidised to inhibit oxidation of cellular compounds (Atmaca 2004). Several investigators have reported iron nanoparticles as a food additive in poultry (Nikonov et al. 2011; Saki et al. 2014), but there was a little information about application of cysteine coated iron oxide nanoparticles as a dietary additive. The results demonstrated that cysteine-coated Fe₃O₄ nanoparticles (Fe₃O₄-Cys NPs) were effective in improving the performance of quails at all supplementary levels compared to negative control. A surprising finding in this study was that the lowest supplementary level of Fe₃O₄-Cys NPs (1.2 mg per kg diet) had similar results as compared with positive control. One of the main purposes of the current study was to evaluate the nutritional potential of Fe₃O₄-Cys NPs in quails with sufficient data regarding nutritional effects of these nanoparticles that were coated with l-cysteine. Actual amount of inorganic iron FeSO₄ 40% was 300 mg per kg of diet while 1.26 mg of Fe₃O₄-Cys NPs was needed to add the diet to provide iron requirements of the quail. Therefore, it would be a great advantage that we could decrease the iron concentration of diet 238 folds using Fe₃O₄-Cys NPs with purity ≥95%. Finally, under conditions of the present study, bioavailability of Fe₃O₄-Cys NPs was similar to that from sulphate for growing quails.

Conclusions

The results confirmed that the corn-soybean meal basal diet, contained 71 ± 12.3 mg Fe per kg, was not sufficient to provide the birds’ iron requirements. Therefore, supplementation of an iron source in the diet is mandatory. Currently, iron sulphate is a common form of iron added to the birds’ diet. The quails performance, haematological and biochemical parameters analyses did not reveal any significant differences between the FeSO₄ and cysteine-coated Fe₃O₄ nanoparticles received groups. So, we conclude that replacing 120 mg/kg iron in form of FeSO₄ with 1.2 mg/kg organic iron in the diet was appropriate for high performance with beneficial effects on the quail.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This work was supported by the University of Kurdistan.