Maternal Iimmunity to Newcastle Disease in Egg Yolk of layers
Awad Alkarim Abdelghaffar Ibrahim, Amal Abu Baker Mohamed Bashir
كلية الطب البيطري-جامعة الخرطوم · السودان
This study was carried out on ninety six egg samples collected from laying hensfrom commercial chicken farm at Alhalfaia (Khartoum North). The hens werevaccinated against Newcastle disease (ND) with the Newcastle disease virus (NDV)vaccine (Komorov strain) produced in the Central Veterinary Research Laboratoriescenter (Khartoum, Sudan).This experimentattempt to detect the presence ofimmunoglobulin Y (IgY) in the egg yolk as a result of transfer of maternalantibodies from immunized hen’s sera to the egg yolk and to study the specificity ofthese antibodies to NDV.The immunoglobulin Y(IgY) was extracted from egg yolkby dextran sulphate method. The method of extraction consists of three steps:Precipitation of lipids by dextran sulphate; precipitation of proteins by sodiumsulphate; and dialysis of precipitateagainst tris- buffered saline (TBS).The presence of IgY in egg yolk, antibody titers and specificity to Newcastledisease virus (NDV) were determined by standardized indirect ELISA (In- houseELISA). All Ninety six samples were found positive (100%). The positive resultswere varied in titers between log213.643 (the maximum) and log28.643 (theminimum). As comparative study, detection of maternal specific NDV IgY wasdone using NDV antibody test kit. All samples tested were found positive andantibody titers were varied between log214.171 (the maximum) and log210.838 (theminimum). It was found that titers obtained from NDV antibody testkit were higherthan those obtained from the standardized indirect ELISA. From this study, it wasfound that maternally derived IgY antibodies present in the egg yolk specific toNDV were present in high titers that confer protection during early weeks of life ofnewly hatched chicks. Extraction of maternally derived specific NDV antibodiesfrom yolk will facilitate accurate monitoring of ND vaccination programmes.