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

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.

doi:2007.20.5.761

Article

Swine Nutrition and Feed Technology

Asian-Australasian Journal of Animal Sciences 2007;20(5): 761-767.
https://doi.org/10.5713/ajas.2007.761 Published online March 5, 2007.

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

L. L. Li, Z. P. Hou, Y. L. Yin^*, Y. H. Liu, D. X. Hou, B. Zhang, G. Y. Wu, S. W. Kim, M. Z. Fan, C. B. Yang, X. F. Kong, Z. R. Tang, H. Z. Peng, D. Deng, Z. Y. Deng, M. Y. Xie, H. Xiong, P. Kang, S. X. Wang

Correspondence: Y. L. Yin,

Abstract

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 ??Landrace ??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.

Keywords: Stress; Metallothionein; Anti-oxidative Enzyme; Superoxide Dismutase Gene Expression; Pork Meat Quality