Effects Of Antibacetiral Peptide On Growth And IGF-1mRNA Expression In Liver And Breast Muscle Of Luhua Chicken

A trial was conducted to study the influence of antibacterial peptide (ABP) ongrowth and IGF-1mRNA expression in liver and breast muscle of Luhua Chicken. Sixhundred one-day-old Luhua chickens with similar weight, healthy were randomlyallocated to2groups with three replicate per group and100birds per replicate (50♂+50♀). The control group was fed the basal diet. For ABP group, tachyplesinantibacterial peptide was supplemented in feed at0.1g/kg of diet. The trial lasted for84days. By comparing the growth performance, the immune organ indexes, serumbiochemical parameters and hormone levels in two groups, we can analyse the growthpromoting mechanism of antibacterial peptide. Meanwhile, the expression level ofIGF-1mRNA in liver and breast muscle was detected by real-time quantitative PCR toknow the molecular mechanism in growth promoting regulation of ABP. This study isaim to provide a theoretical and scientific basis for the development and application ofABP, improve the growth performance and immune performance of Luhua chickenand promote the development of Luhua chicken feeding. Results are as bellow:1ABP significantly improved the production performance of Luhua chicken. Atthe age of84d, compared with the control group, the weight of ABP group increasedby6.00%(P<0.01), ADG increased by6.10%(P<0.01), ADFC decreased by4.34%(P<0.01), F/G decreased by9.97%(P<0.01); At the age of56d,70d and84d, the bodyweight of ABP group was significantly higher than the control group (P<0.01); During42～56d and70～84d, compared to the control, the ADG of ABP group respectivelyincreased by21.37%(P<0.01) and7.89%(P<0.01); During1～14d,29～42d,57～70d and71～84d, the ADFC of ABP group was significantly lower than the controlgroup (P<0.01); During1～14d,29～42d,43～56d and70～84d, compared to thecontrol, respectively, the F/G of ABP group decreased with28.57%,8.81%,14.11%and15.00%(P<0.01). 2ABP could improve the immune organ indexes of Luhua chicken, and promotethe development of immune organs. At the age of28d, feeding ABP significantlyincreased thymus index (P<0.01); At the age of14d,28d,56d,70d and84d, comparedto the control, the bursal index of ABP group were higher (P<0.01); Throughout thewhole process of growth, the immune organ indexes of ABP group were higher thanthe control; The bursal index and spleen index increased during14～28d, then theimmune organ indexes decreased as age increasing.3Compared with the control group, feeding ABP reduced42d Luhua chickenserum UN and TC levels by21.74%(P>0.05) and4.76%(P>0.05), increased TP andGlb concentrations by6.39%(P>0.05) and20%(P>0.05); At the age of56d,compared to the control group, serum TC and TP levels of ABP group decreased by16.03%(P>0.05) and10.34%(P>0.05); At the age of70d, the UN level of ABP groupwas lower than the control with35.71%(P>0.05), feeding ABP increased the TP levelby16.41%(P<0.05).4As to serum growth hormone level, there is no significant difference betweentwo groups (P>0.05); At the age of14d,28d and42d, the ABP-treated group hadhigher serum growth hormone level than in the control group by43.14%,2.35%and10.53%(P>0.05); At the age of56d,70d and84d, compared with the control, theABP-treated group had lower serum growth hormone level by7.94%,4.76%and9.41%(P>0.05).5Compared to the control group, at the age of14d, feeding ABP significantlyimproved serum T4level with40.37%(P<0.05); At the age of42d, compared with thecontrol, the serum T3level of ABP-treated group was higher by12.69%(P>0.05); Atthe age of84d, compared with the control, feeding ABP reduced serum T3and T4levels by20.22%(P>0.05) and5.37%(P>0.05).6At the age of84d, compared with the control, ABP-treated group had higherserum IGF-1level with18.85%(P<0.05).7ABP had no significant effect on IGF-1mRNA expression in liver and breastmuscle of Luhua Chicken (P>0.05).Conclusion: ABP could significantly increase weight and ADG, decrease ADFCand improve the growth performance of Luhua chicken; Feeding ABP significantly improved the bursal index and thymus index, promoted the development of immuneorgans; ABP lowered serum UN concentration, significantly raised70d serum TP leveland promoted protein synthesis; Feeding ABP could significantly raise serum14d T4level and regulate the growth of Luhua chicken; ABP could significantly improve the84d serum IGF-1level, but ABP had no impact on the expression of IGF-1gene inliver and breast muscle of Luhua Chicken.