In Ovo Vaccination Of Chickens With Original Antibodies With Lasota Vaccine

Eighteen-day-old chick embryo with original antibody includes low antibody titer and high antibody titer were vaccinated with Newcastle disease(ND) Lasota vaccine.The variation of antibody was detected by HI and ELISA assay.Chick embryos were getted from the same batch hens and were hatched together.Hatching eggs were drawled from one discus with random;yolk was detected b-y HI.The range ability of valence of HI for high original antibody is 6.5～7.5(Log₂),150M.;For low original antibody the range ability is 3.5～4.5(Log₂), 150M.Put the two batches into four group,the first group:m ovo vaccination group,all the ovos were vaccinated Lasot-a with 1 portion at 18-day-old;the second group:one-day-old vaccination group,all the chic-ks were vaccinated Lasota with 1 portion at one-day-old;the third group:all the chicks were vaccinated when antibody was at the peak time;the fourth group:unvaccinated control group.One day later 15 birds' blood of every group were drawled,the serum was detected by HI and ELISA assay.The result indicated:Chick embryo immunity of low antibody titer class showed higher valence of HI and ELISA than one-day-old immunity class and four-day-old immunity class,the statistical analysis shows significance(P＜0.05);Chick embryo with high origin antibody titer immunity class,one-day-old immunity class and four-day-old immunity class show insignificance(P＞0.05) by statistic analysis.The antibody was determined by HI usingβ- micro method,average titer was expressed as geometric means(Log₂n).