关键词: 生长猪, 生产性能, 蛋白质利用, 生长激素释放肽-2

Abstract: 10 DLY growing pigs at (26.55±1.36) kg of mean body weight were allocated into control and treatment group randomly and the treatment pigs were injected with GHRP-2 intramuscularly at the dose of 30 μg/kgBW respectively every day for 15 days to investigate the the growth performance and protein utilization, then to investigate the growth performance in the following 15 days without injection. Compared with the control pigs, the average daily gain of treatment pigs increased by 7% during the period from day 1 to day 5 and decreased in the following treatment days (P>0.05), the F/G of treatment pigs decreased by 11.1% during the period from day 1 to day 5 and increased in the following treatment days (P>0.05), there was no remarkable effect on the daily feed intake; protein utilization from day 6 to day 10 was reduced (P>0.05); and the net protein utilization decreased 8.5% (P=0.01) in this period. The protein synthesis, protein breakdown and the protein net utilization decreased numerically during the period from day 7 to day 8. On the 15th day, the GH was stimulated by GHRP-2 and significantly increased (P=0.01) in terms of means in treatment pigs. The urea nitrogen and total protein of serum decreased and increased numerically respectively (P>0.05). During the period of stopping GHRP-2 treatment, compared with the control pigs, the average daily gain of treatment pigs increased by 16.85%, 10.23%, 1.11% in the first 5 days, the first 10 days and the whole 15 days respectively, the F/G of treatment pigs decreased by 13.7%, 8.82%, 5.51% in the first 5 days, the first 10 days and the whole 15 days respectively, the daily feed intake had nearly no change. In conclusion, GHRP-2 treatment nearly had no improvement on the average daily gain and protein utilization of DLY growing pigs, but it may have the subsequent effect to the pigs during the period of stopping GHRP-2 treatment.

Key words: pig, growth performance, protein utilization, GHRP-2