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TCND was first estublishad by R.A. Banlcowski in 1948, who cu1tivai NDV California 11914 stain on thsue culture, The sI stain Irelongal to Mesogenic te. Owing to heterotypic cell was adoped for TCND virus multiplication, it could ke fr from eggteansmission. To realize the character of TCNIJ virus and the wactical prcceduxe of vaccine geparation, a se& stain was intrcduced from Japan in 1971. The exjtrimenl dat was summari1 as follows:
1.The titers of manufacturer! TCND sJ virus were 10^(7.1)EID 50/0.1mll,10^(7.2) TCID 50/0.1m1 and X16 HA titer. All but nervous incculation into chickens could induce no fatal reaction.
2. There lot of manufactured vaccine were inoculati into 39 chickens resntively for Summary safety test and no reaction was found. The protection efficiency reached 1(0% when virus challenge was given.
3. The virus multiplication in 5K cells reacher! the highest titer during 65-75 hours yxtinco,1ation. It was found that TCIDSO titer was higher than that of EIDSO but HA titer was very low.
4. The titer of ND natural antibcdy in one flock of chicken was surveyed. It showed that theorginaltiterwasHlOM x2216,butdecseasedtoxl.14 whenchickens aged within 15 days.
5. The manufactured TCNI) live vaccine had 1(0% protection efficiency in one dcte when the thickens with natural antibcdy reached 5 weeks old.
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