Effects of monoclonal antibody on fat tissue development, carcass composition, growth performance and fat metabolism of pigs by subcutaneous injection

This study was to investigate the effects of monoclonal antibody against a porcine 40-kDa adipocyte-specific plasma membrane protein on fat tissue development, carcass composition, growth performance and fat metabolism in pigs. Forty-eight Landrace × Saba pigs were randomly divided into eight groups, the control group was given 16 mL saline and the treat groups were given the monoclonal antibody (McAb) with 0.1, 0.5 or 1.0 mg/kg body weight at 30 kg or 60 kg body weight respectively by subcutaneous injection. The results showed that the injection of 1.0 mg/kg monoclonal antibody at 30 kg or 60 kg could increase the lean meat percentage by 3.04% or 4.25% (P < 0.05) respectively, decrease fat percentage by 10.50% or 9.32% (P < 0.05) and backfat thickness by 16.28% or 18.65% (P < 0.05) respectively under the condition of unchanged growth performance. Moreover, the injection of 1.0 mg/kg monoclonal antibody at 30 kg body weight could significantly increase serum LPL activities by 13.79%, 25.00%, 43.91%, 21.77% and 11.61%(P < 0.05) at 1 to 5 weeks respectively after injection, increase serum TG contents by 7.83%, 11.08% and 5.37% (P < 0.05) at 2 to 4 weeks respectively after injection, but reduce serum NEFA levels by 6.58%, 7.80% and 8.15%(P < 0.05) at 1 to 3 weeks respectively after injection. The injection of 1.0 mg/kg monoclonal antibody at 60 kg body weight could significantly increase serum LPL activities by 10.02%, 18.77% and 14.26%(P < 0.05) at 1 to 3 weeks respectively after injection, increase serum TG contents by 9.23%, 9.70% and 8.67%(P < 0.05) at 2 to 4 weeks respectively after injection, but reduce serum NEFA levels by 15.46%, 16.64%, 13.96% and 10.85%(P < 0.05) at 1 to 4 weeks respectively after injection. Meanwhile, this antibody could restrain subcutaneous fat tissue development by reducing the diameter and triglyceride contents of subcutaneous fat cells. This suggested that this McAb could improve the carcass composition by reducing fat percentage which was regulated by increasing fat mobilization and suppressing the fat deposition in adipose tissue.