Effect Of A Synthetic Growth Hormone-releasing Peptide-2 On Growth And Carcass Traits In The Finishing Pigs

This study was carried out to examine the effect of the injection a synthetic growth hormone-releasing peptide-2 (GHRP-2) on growth performance and carcass traits in the finishing boars. 10 three-line crossbred boars DLY (Duroc×Landrace×Yorkshire) and 10 Ya Nan boars were allotted to 4 groups, The treatments were: (1) Saline was injected; (2) 20 ugGHRP-2/kgBW was injected by intramuscular every two days. The average daily gain (ADG).. food-intake and feed efficiency were noted. Feeding experiment lasted 28 days, at 29 day, all pigs were slaughtered. After slaughter a bit of longissimus muscle were taken from each pig for fat detection. In the same time, the carcass length, back-fat thickness, rib longissimus muscle area and dressing percentage were examined. Results show.-1. Compared to the control group,the DLY treatment group made ADG and feed effiency singnificantly to increase 14. 15%(P<0.05) and 11. 92%(P<0. 05) respectively, but difference were not significant for the ADFI (P>0.05) ( 3.19 ± 0.16Kg VS 3.2 ± 0.2Kg) . As for the Ya Nan treatment group, the ADG and feed effiency increased 4.78% (P>0. 05) and 6.63%(P>0. 05) respectively. The same to the DLY, the ADFI were no diffference (2.37 ± 0.3 VS 2.31 + 0.2) .2. The obviously phase effect on growing performance were observed in both two genotype pigs. In The 1st week, the DLY and Ya Nan treatment group made ADG to increase 35. 31%(P<0.01)和 25.7%(P<0.05)respectively, thoughin 2nd week> 3rd week, the effect was lowed even nagative effects was occurred. The good effect was occurred till 4th week.3. For both two genotype groups, there was no obviouse effect on the carcass length , back-fat thickness> rib longissimus muscle area> dreassing percentage and intra-muscular fat in the treatment group.4. Compared to the control group , the utilization of dietary protein increased 7.46% (P<0.05) in DLY pigs , and the apparent nutrition digestibility of dietary protein increased 2. 78% (P<0. 01) in Ya Nan pigs.Conclusions: 20 ug GHRP-2/kgBW was injected by intramuscular every two days can increase growth performance and the utilization of dietary protein obviously for the DLY pigs except the carcass traits. This treat increased the apparent nutrition digestibility of dietary protein but . not affect the growth performance and carcass traits obviously for the Ya Nan pigs . This indicates that the improve effect of growth performance was related with the genotypes and the DLY exhibit better than Ya Nan. The obviously phase effect on growing performance were observed in both two genotype pigs.