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In the raxnt years, the Asian ype of Ikwcasfle disease widely occunal in tie Asia area and causal )tavy losses in poulixy industy. In Taiwan, a seric*is outbreak has cccurxai since 1%8. Although tie government did a lot of work on tie jnvention, the disease still ccmstitutd a major mnenance in Taiwan; Hence a croper application of ND vaccine was c’signer1 for the pflnii.
1 .The degree of irnmwiity in hens inuitencal the tite cC jntal antibody, which varied among a same group of chicks and disappeared almost comptly in 30 days.
2.WAen a formnahn- killed ND vaxine without the juvant of Al(OH)3 was adininistratlintravenously, UeHltitrereacheittlerangofl00-18)Xontle4th day. it even leveled to ?tOXin those ever vacdnatd chickens on the 6th day and last ot out montit To those unvaixinaal ones, the HI tite kept somewhat lower and droppel so 8.2Xon tIe 15th day. In short, the vaccination by intravenous rout was eff&nve for an errergent control.
3.The first dose of forrn alin-klllaJ ND vaccine would jioduce 1 8.2Xof HI titr in the chicken lackof parnlantibcdy, aged 3 weeks oki, and eptthevalueforaericd of 4 weeks, when the sfto,xl dose was given, the georretit mean ofHI titre radly reached so 56.3Xuntil 8 weeks ha.
4.The method of live vaccine given at the age of 4,14 and 28 days respairvely, then bocetaed with fonrnalin-kilW v&xiie 2 months ha, also could obGin a good
Snaiwiary prevention.
5.The mnethcd ofBl inoculation by nasal rout at the age of 4 days, then fonnalin-ldllai ND vaccine mtion at the 4th week old and at the inti-val of every 3 months, was carried out in two grout of 14,000 chickens. The moiEAdity and mortality were agrarently ckeasel.
6.After inoculation of live vaccine by nasal rout at the age of4 days, the chickens were resaDtively vacdnaJ at tie age of 4,8,14 and 22 weeks old, then bcxxtered with fonnalin-kil3 vaixire at tie intrval of every 2-3 months, 55(1) chicks by sith vaccmaton were &terved for 33 weeks. The avenge HI titre was 10- 80X, neutittion antibody titre was 2.4-3.5 log. The ra of proeonon was as high as 80- 100%.
7.A method was desigxtl that lerisogenic virus was given prior to mesogenic type vaccination. Aft Bi application by nasal rout at the age of 4 days, the cht when aged 30 days took another infrtion of TCND. Tie HI tite didn coincide with VN title, The former was 5-40(SXin avenge), the ha reached to 1 1SX1? days after TQ’ID mjnt arid ke 1 SXfor 6) days. Therefore it was heer to adopt VN titie or prevention est as an indicator for TCND effect.
8.The method ofBl or Lasota v&xine mc*ilaticin at ageof4 days by nasal rou thz by spray app&aiio,i at the age of 14 days was ‘tet than that of Las vaczne inxuiation by nasal rout at the age of 4 days and 14 days.
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