Intramuscular Administration of Zinc Metallothionein to Preslaughter Stressed Pigs Improves Anti-oxidative Status and Pork Quality

• Published in: Asian-australasian journal of animal sciences Vol. 20; no. 5; pp. 761 - 767
• Main Authors: Li, L.L, Hou, Z.P, Yin, Y.L, Liu, Y.H, Hou, D.X, Zhang, B, Wu, G.Y, Kim, S.W, Fan, M.Z, Yang, C.B, Kong, X.F, Tang, Z.R, Peng, H.Z, Deng, D, Deng, Z.Y, Xie, M.Y, Xiong, H, Kang, P, Wang, S.X
• Format: Journal Article
• Language: Korean
• Published: 2007
• Subjects: Superoxide Dismutase Gene Expression; Stress; Metallothionein; Anti-oxidative Enzyme; Pork Meat Quality
• ISSN: 1011-2367; 1976-5517

This study was conducted to determine the effects of exogenous zinc-metallothionein (Zn-MT) on anti-oxidative function and pork quality. After feeding a corn-soybean meal-based diet for two weeks, 48 pigs ($Duroc{\times}Landrace{\times}Chinese\;Black Pig$) were assigned randomly to four groups. Pigs in Group 1 were maintained under non-stress conditions, whereas pigs in Groups 2, 3 and 4 were aggressively handled for 25 min to produce stress. Pigs in Groups 1, 2, 3, and 4 received intramuscular administration of saline (control group; CON), 0 (negative control group; NCON), 0.8 (low dose group; LOW), and 1.6 (high dose group; HIGH) mg rabbit liver Zn-MT per kg body weight, respectively. Pigs were slaughtered at 3 and 6 h post-injection. Zn-MT treatment increased (p<0.05) the activities of superoxide dismutase (SOD) and glutathione-peroxidase (GSH-PX) while decreasing the concentration of malondialdehyde (MDA) in liver. These responses were greater (p<0.05) at 6 h than at 3 h post Zn-MT injection. Zn-MT treatment increased (p<0.05) hepatic SOD mRNA levels in a time and dose-dependent manner and decreased (p<0.05) serum glutamate-pyruvate transaminase and lactate dehydrogenase activities (indicators of tissue integrity). Zn-MT administration decreased (p<0.05) lactate concentration and increased (p<0.05) pH and water-holding capacity in the longissimus thorasis meat. Collectively, our results indicate that intramuscular administration of Zn-MT to pre-slaughter stressed pigs improved tissue anti-oxidative ability and meat quality.