Different iron sources affected haemoglobin and myoglobin synthesis, and gene expression related to iron metabolism in skeletal muscle in piglets

Figures & data

Table 1. Primer sequences used for real-time PCR¹.

Gene	Forward (5′ - 3′)	Reverse (5′ - 3′)	Product length (bp)	Accession numbers
DMT-1	TTGGCTATCATTGGCTCAG	ACGATGGCAGGAACATTC	271	NM_001128440.1
HFE	TGGTCATTGGAATCATCAGT	TCATTCACATTCGGCTAAGA	131	XM_021098424.1
FTH1	ACTTCATTGAGACGCATTAC	GATGTTCTGGTAGGACTTATAG	260	NM_213975.1
HEPH	GGACCACTCATAACCTGTAA	CATCCTATTGCTCTCCTGAA	204	XM_021079775.1
Fpn1	GGTTCTTACTTCCTGCTATATC	ACTGGTCAATCCTTCGTATT	167	XM_003483701.4
HJV	TTGGCAAGGAAGAACAGAA	CCACAACCGATAAGATTATAGG	261	XM_005663519.3
LCN2	GCTCTGTGACAACTGGAT	GAAGAATACTATGGCGAACTG	148	XM_021088538.1
TFR1	TCTCAGTCATCAGGATTGC	GCTTCACATTCTTACTTGGT	154	NM_214001.1
TFR2	GATAAGTTCCACGCCAAGA	GGTTCTCATAGGTGTCATCC	277	XM_003124374.5

¹ DMT-1, Divalent metal-ion transporter 1; HFE, hemochromatosis; FTH1, Ferritin heavy chain 1; HEPH, Hephestin; Fpn1, Ferroportin 1; HJV, Hemojuvelin; LCN2, Lipocalin 2; TFR, Transferrin receptor.

Table 2. Effects of different iron sources on hematological parameters in blood in pigs at 28 d^1,2.

Item	Control	Ferrous sulphate	Ferrous glycinate	Amino acid-Fe(II)-chelator complexes	P value
Red blood cell count (10^6 cells/μL)	4.05 ± 0.68	3.31 ± 0.30	3.52 ± 0.60	3.43 ± 0.53	0.783
Haemoglobin (g/L)	53.80 ± 8.79	56.40 ± 5.92	58.60 ± 11.14	54.00 ± 8.79	0.977
Mean corpuscular volume (MCV, fL)	48.72 ± 1.92^b	56.74 ± 0.59^a	55.64 ± 0.76^a	52.78 ± 2.01^ab	0.007
Mean corpuscular haemoglobin (MCH, pg)	13.26 ± 0.32^b	16.92 ± 0.40^a	16.46 ± 0.34^a	15.70 ± 0.70^a	0.000
Mean cell haemoglobin concentration (MCHC, g/L)	310.20 ± 2.82^b	325.00 ± 3.91^a	324.20 ± 4.62^a	316.40 ± 3.91^ab	0.048
Red blood cell distribution width proportion	18.12 ± 0.26	17.32 ± 0.52	17.78 ± 0.48	17.56 ± 0.41	0.606

¹ Values are means ± SE, n = 6 per treatment.

^2a,b Values in the same row with different superscript letters are significantly different (P < 0.05).

Table 3. Effects of different iron sources on meat colour in pigs at 28 d¹.

Item	Control	Ferrous sulphate	Ferrous glycinate	Amino acid-Fe(II)-chelator complexes	P value
Longissimus dorsi muscle
Lightness (L*)	50.72 ± 2.13	48.56 ± 2.57	49.17 ± 1.65	51.22 ± 2.45	0.81
Redness (a*)	21.22 ± 0.73	21.78 ± 1.06	21.00 ± 0.32	20.89 ± 0.80	0.85
Yellowness (b*)	11.11 ± 0.86	10.45 ± 0.51	9.72 ± 0.31	10.56 ± 0.47	0.41
Gastrocnemius muscle
Lightness (L*)	55.00 ± 3.26	52.60 ± 1.25	52.00 ± 0.85	54.22 ± 2.03	0.72
Redness (a*)	22.00 ± 0.59	25.11 ± 0.67	23.11 ± 1.55	23.05 ± 0.54	0.16
Yellowness (b*)	11.17 ± 0.41	12.61 ± 0.67	11.06 ± 1.49	11.05 ± 0.52	0.54

¹ Values are means ± SE, n = 6 per treatment.

Table 4. Effects of different iron sources on myoglobin (Mb) content in muscles in pigs at 28 d^1,2.

Item	Control	Ferrous sulphate	Ferrous glycinate	Amino acid-Fe(II)-chelator complexes	P value
Longissimus dorsi muscle (mg/g)	1.16 ± 0.10^b	1.61 ± 0.10^a	1.89 ± 0.11^a	1.60 ± 0.12^a	0.001
Gastrocnemius muscle (mg/g)	1.22 ± 0.15^c	1.69 ± 0.10^ab	1.95 ± 0.05^a	1.58 ± 0.09^b	0.001

¹ Values are means ± SE, n = 6 per treatment.

^2a,b Values in the same row with different superscript letters are significantly different (P < 0.05).

Table 5. Effects of different iron sources on the protein, DNA and RNA contents in muscles in pigs at 28 d^1,2.

Item	Control	Ferrous sulphate	Ferrous glycinate	Amino acid-Fe(II)-chelator complexes	P value
Longissimus dorsi muscle (mg/g)
Protein (mg/g)	70.87 ± 4.16	68.89 ± 2.43	68.12 ± 2.24	76.78 ± 4.06	0.247
RNA/DNA (μg/μg)	0.48 ± 0.05	0.44 ± 0.04	0.43 ± 0.04	0.46 ± 0.03	0.862
Protein/DNA (mg/μg)	0.13 ± 0.01	0.13 ± 0.01	0.13 ± 0.01	0.14 ± 0.01	0.451
Gastrocnemius muscle
Protein (mg/g)	43.86 ± 4.41	56.66 ± 2.74	49.45 ± 4.77	52.57 ± 4.35	0.200
RNA/DNA (μg/μg)	0.30 ± 0.01	0.35 ± 0.01	0.35 ± 0.04	0.39 ± 0.04	0.294
Protein / DNA (mg/μg)	0.08 ± 0.01	0.11 ± 0.01	0.09 ± 0.01	0.10 ± 0.01	0.293

¹ Values are means ± SE, n = 6 per treatment.

^2a,b Values in the same row with different superscript letters are significantly different (P < 0.05).

Table 6. Effects of different iron sources on genes expression related to iron metabolism in muscles in pigs at 28 d^1,2,3.

Item	Control	Ferrous sulphate	Ferrous glycinate	Amino acid-Fe(II)-chelator complexes	P value
Longissimus dorsi muscle
DMT-1	1.00 ± 0.07	0.79 ± 0.06	0.96 ± 0.08	0.79 ± 0.04	0.056
HFE	1.00 ± 0.10	0.88 ± 0.09	1.13 ± 0.05	0.94 ± 0.10	0.245
FTH1	1.00 ± 0.07	0.86 ± 0.08	0.95 ± 0.11	0.99 ± 0.09	0.702
HEPE	1.00 ± 0.10	1.65 ± 0.06	1.30 ± 0.16	1.68 ± 0.35	0.088
Fpn1	1.00 ± 0.06^ab	1.14 ± 0.05^a	1.08 ± 0.07^a	0.85 ± 0.06^b	0.014
HJV	1.00 ± 0.14	0.79 ± 0.09	1.03 ± 0.04	0.79 ± 0.05	0.113
LCN2	1.00 ± 0.06^b	0.87 ± 0.05^b	1.64 ± 0.20^a	1.12 ± 0.23^b	0.015
TFR1	1.00 ± 0.10^a	0.39 ± 0.06^c	0.72 ± 0.08^b	0.53 ± 0.06^bc	0.000
TFR2	1.00 ± 0.14^a	0.81 ± 0.21^ab	0.41 ± 0.06^b	0.84 ± 0.10^a	0.044
Gastrocnemius muscle
DMT-1	1.00 ± 0.07	0.85 ± 0.13	0.79 ± 0.13	0.96 ± 0.10	0.522
HFE	1.00 ± 0.09	0.83 ± 0.08	0.90 ± 0.09	0.88 ± 0.05	0.493
FTH1	1.00 ± 0.09	0.94 ± 0.09	0.72 ± 0.10	1.08 ± 0.12	0.088
HEPE	1.00 ± 0.09	1.56 ± 0.13	1.81 ± 0.44	1.65 ± 0.26	0.202
Fpn1	1.00 ± 0.09^b	1.00 ± 0.07^b	1.06 ± 0.05^b	1.38 ± 0.15^a	0.033
HJV	1.00 ± 0.13	1.1 ± 0.18	0.62 ± 0.05	0.79 ± 0.11	0.062
LCN2	1.00 ± 0.07^b	1.67 ± 0.15^a	1.90 ± 0.29^a	1.79 ± 0.16^a	0.012
TFR1	1.00 ± 0.07^a	0.54 ± 0.08^b	0.74 ± 0.12^ab	0.96 ± 0.16^a	0.025
TFR2	1.00 ± 0.52	0.38 ± 0.12	0.40 ± 0.14	1.03 ± 0.31	0.298

¹ DMT-1, Divalent metal-ion transporter 1; HFE, hemochromatosis; FTH1, Ferritin heavy chain 1; HEPH, Hephestin; Fpn1, Ferroportin 1; HJV, Hemojuvelin; LCN2, Lipocalin 2; TFR, Transferrin receptor.

² Values are means ± SE, n = 6 per treatment.

^3a,b Values in the same row with different superscript letters are significantly different (P < 0.05).