The Effect Of Synthetic Small Peptides On Immunological Response Of Newcastle Disease Vaccine In The Broiler Chicken

It si an important task to prevent and control the newcastle disease in the poultry industry.However,the problem to the NDV vaccine is that the immunological response is not strong and duration enough,which resulted in that development of a safe and reliable production and promotion of low cost to improve the effect of NDV vaccine is particularly urgent.The aim of this study was to compare the effect of four synthetic small peptide on the immune response of newcastle disease and find out onesynthetic small peptide with optimal effectand its optimal concentration.The main contents of this study are as follows.Part One Effect of four synthetic small peptides on the immune response of newcastle disease vaccine in the broiler chickenIn order to explore the effect of different synthetic small peptides on the immune response of newcastle disease vaccine in the broiler chicken,900 AA broilers()at 1 day age were randomly allotted to six groups including newcastle disease vaccine free treatment group,newcastle disease vaccine treatment group,newcastle disease vaccine+T4-3H4 treatment group,newcastle disease vaccine+T4-3T4 treatment group,newcastle disease vaccine+T4 treatment group and newcastle disease vaccine+3H4treatment group.Each group had three replications and each replication had 50 broilers.Broilers in different treatment groups had free access to the water mixed with different synthetic small peptides,and two broilers were selected from each replication to collect blood sample on day 0,7,14,21,28 and 35 after vaccination to determine the antibody titer of newcastle disease vaccine.Results showed that feeding of synthetic small peptide to broilers increased the antibody titer of newcastle disease vaccine,3H4 had the best effect.Part Two:Identification of the optimal concentration of synthetic small peptide to improve the immune response of newcastle disease vaccineIn order to explore the optimal concentration of synthetic small peptides(3H4),270broilers(AA)aged 1 day were randomly allotted to high concentration 3H4 treatment group(2ug/150L),middle concentration 3H4 treatment group(1ug/150L)and low concentration 3H4 treatment group(0.5ug/150L).Each group had three replications and each replication had 30 broilers.Broilers in different treatment groups had free access to the water mixed with 3H4 at different concentrations,and two broilers were selected from each replication to collect blood sample on day 0,7,14,21,28 and 35 after vaccination to determine the antibody titer of newcastle disease vaccine.Results indicated that feeding of3H4 at a concentration of 1ug/150 L to broilers achieved the best immunity effect.