Effects of Slow Release Recombinant Porcine Somatotropin (rpST) Administration on Growth Performance and pST and IGF-1 of Blood in Finishing Pigs

摘要

The present study was performed to investigate the effect of plant type recombinant porcine somatotropin (pST) adminstration on growth performance and blood profile of finishing pigs. Forty-eight Landrace barrows weighing 78 kg were employed for six week growth trial. Twelve barrows were allocated into various rpST types ; the control (CONT), the 4:1 type rpST (TRT 1), the 1:1 type rpST (TRT 2); and the 4:1 type rpST group(TRT 3) respectively. CONT group were not planted rpST. TRT 1 group was treatedwith rpST once a week for 6 weeks. Each dose contained the rpST equivalent to 100mg from initial to two weeks and 125mg from three weeks to finial week. TRT 2 and TRT 3 groups were planted rpST four times contained the rpST equivalent to lOOmg during trial period from initial to two weeks, and 125 mg from three weeks, to four weeks, respectively. All pigs were fed a commercial feed containing 0.9% lysine ad lib. Daily gain increased by 19.4% in TRT l(p<0.05) compared to the CONT. rpST improved feed/gain by 13.4—28.9% in all treatment groups(p<0.05). Back fat thickness of the all rpST treated groups were 23.3-29.2% thinner than that of the CONT. These results indicated that the rpST stimulated growth performance in finishing pigs and plant type rpST could be used as a growth stimulant for finishing pigs.