Broiler responses to copper levels and sources: growth, tissue mineral content, antioxidant status and mRNA expression of genes involved in lipid and protein metabolism

Table 5 Antioxidant enzyme activity and malondialdehyde concentration in 17 d old broiler chicks fed different copper levels and sources

Item	Copper levels, mg/kg					Mean		SEM¹	Source	Level	Source × Level	L²	Q³
Item	0	4	8	12	16	Inorganic	Organic
*Breast muscle*
Superoxide dismutase, g/g pro	1.62	1.61	1.66	1.66	1.62^b	1.66^a	1.61^b	0.013	0.050	0.471	0.173	0.499	0.266
Glutathione Peroxidase, IU/g pro	398	391	358	403	404	491^a	291^b	14.6	< 0.01	0.303	0.001	0.653	0.143
Inorganic	436	507	454	515	541			11.9				< 0.01	0.795
Organic	361	274	263	291	268			12.2				0.028	0.068
p-value⁴	< 0.01	< 0.01	< 0.01	< 0.01	< 0.01
MDA, mg/kg	0.0100	0.0161	0.0161	0.0161	0.0162	0.0181	0.0117	0.002	0.083	0.738	0.385
*Liver*
Superoxide dismutase, g/g pro	363	327	292	313	320	341^a	306^b	8.67	0.033	0.101	0.164	0.081	0.042
Glutathione Peroxidase, IU/g pro	2624	2608	2592	2475	2510	2951^a	2173^b	51.1	< 0.01	0.170	0.193	0.030	0.991

¹Standard error of means
²Linear effect of dietary copper levels
³Quadratic effect of dietary copper levels
⁴Effect of the source (organic and inorganic) on Glutathione Peroxidase activity by dietary copper levels
Organic: copper proteinate (CuPro) and organic trace minerals; Inorganic: copper sulphate (CuSO_4.5H₂O) and inorganic trace minerals; MDA: malondialdehyde
^a⁻^bMeans with a different superscript in a row are different (P < 0.05)

ISSN: 1746-6148