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Effects of Weekly Administration of Implant-type Recombinant Porcine Somatotropin on the Performance and Carcass Characteristics of Finishing Pigs |
Y. H. Kim, H. J. Jung, J. C. Park, O. S. Kwon, C. S. Chung, Y. D. Ko, H. K. Moon |
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Abstract |
The present study was undertaken to investigate the effects of weekly administration of implant type recombinant porcine somatotropin (rpST) on the performance and carcass characteristics in finishing pigs. A total of 120 crossbred (Landrace횞Yorkshire횞Duroc) pigs were employed for 11 weeks in a growth trial in experiment. A rpST designed to implant every 7 d was used. Forty pigs, each weighing 75 kg, were allocated into three rpST treatments; control (CONT), implant of rpST from 75 kg (TRT1) or 90 kg (TRT2) of body weight. The CONT pig and pigs in TRT2 from 75 kg to 90 kg were treated without rpST but with placebo. In rpST-treated pigs, each 100 mg and 125 mg of the equivalent rpST was implanted from live weight of 75 kg to 90 kg and from 90 kg to market weight, respectively. Half of the pigs from each treatment were marketed at live weight of 110 kg and the rest at 130 kg. All pigs were allowed ad libitum access to a commercial feed containing 0.94% and 0.88% of lysine from 75 to 110 kg, 110 to 130 kg of body weights, respectively. rpST had no effect on daily gain, while feed efficiency was improved by 7 to 13% (p<0.05) in the rpST-treated groups compared with the CONT. Compared with the CONT, backfat thickness was decreased by 12% (p<0.05) in TRT1 at 110 kg of market weight, and by 23 to 32% (p<0.05) in the rpST-treated groups at 130 kg of market weight, respectively. Lean muscle rate tended to be higher in TRT1 at both 110 kg and 130 kg of market weight, and carcass fat percentage in the rpST-treated groups was decreased by 33 to 46% (p<0.05) compared with the CONT. |
Keywords:
Recombinant Porcine Somatotropin; Growth Performance; Carcass Quality; Hormones; Finishing Pigs |
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