Effects of active immunization against myostatin on carcass quality and expression of the myostatin gene in pigs.

The study was conducted to investigate the effects of active immunization against myostatin on the titer of myostatin antibody, carcass evaluation, activity of creatine kinase and the expression of the myostatin gene in pigs. Eighteen pigs were allotted into three groups (six pigs per group), and pigs in treatment 1, 2 and 3 were immunized with physiological saline, 1 mg or 4 mg myostatin per pig, respectively. Six pigs were killed by electrical stunning followed by exsanguination at BW of 100 kg. The results indicated that the titer of myostatin antibody was increased in treated groups compared to the control group on day 42 (P < 0.01) and d 84 (P < 0.01). The carcass lean percentage was significantly increased in the treatment groups compared to the control group (P < 0.01), and intramuscular fat was significantly decreased in the 4 mg group compared to the control group (P < 0.05). The muscle creatine kinase activity of pigs treated with 1 mg and 4 mg myostatin was lower than the control group. The immunization of myostatin significantly decreased the myostatin gene expression levels in muscle. It was concluded that optimal active immunization against myostatin could increase the content of myostatin antibody, suppress the activity of creatine kinase and the expression of myostatin gene, and therefore improve the carcass lean percentage for pigs.