Evaluation of pre-slaughter low-current/high-frequency electrical stunning on lipid oxidative stability, antioxidant enzyme activity and gene expression of mitogen-activated protein kinase/nuclear factor erythroid 2-related factor 2 (MAPK/Nrf2) signalling pathway in thigh muscle of broilers

This study was aimed to evaluate the effects of pre-slaughter low-current/high-frequency (LH) electrical stunning (ES) on lipid oxidative stability, antioxidant enzyme activity and gene expression of mitogen-activated protein kinase/nuclear factor erythroid 2-related factor 2 (MAPK/Nrf2) signalling pathway in thigh muscle of broilers. Eighteen birds were randomly allocated to the following three treatments with six replicates per treatment and one bird per replicate: without stunning (control); water-bath ES with sinusoidal alternating LH (86 mA, 1000 Hz, LHES) or high current/low frequency (HL) (130 mA, 60 Hz, HLES). Stunning methods did not affect malondialdehyde level (d 0 similar to d 9) or antioxidant enzymes' activity at d 0 similar to d 2. LHES enhanced glutathione S-transferase activity at d 3 and gene expression of MAPKs and Nrf2 compared with HLES. In conclusion, LHES enhanced gene expression of MAPK/Nrf2 pathway, whereas had no superiority over HLES in lipid oxidative stability (4 degrees C, 9 days) of thigh muscle in broilers.