engleski

Newly hatched turkeys given La Sota by nebulization is safe and immunogenic

Objectives: Immune response and safety of commercial vaccine Pestikal® ; ; SPF La Sota given by nebulization to newly hatched turkeys was investigated. Material and methods: Alltogether 40 newly hatched turkeys were disposed into three groups (A, B, C) (Table 1). Group A was exposed to the water suspension of La Sota veccine for 60 seconds as well as group B during 300 seconds, while group C, as a control group, wasn’ ; ; t treated at all. All the remedies mentioned were applied by ultrasonic nebulizer SONOVAC 095® ; ; (Figure 1) which develops particles ranging 2-5 microns in diameter (Mazija and Štimac, 1995) The immune status was controlled by analyzing sera samples every 7 days starting on 7th day till 35th day, and in challenged subgroups on 38th day as 10 days after challenge. Collected sera were analyzed by standard microtiter method of hemagglutination-inhibition test (Allan et all, 1978) to detect specific antibodies against vaccine virus. Challenge was performed at 28th day on A1, B1, and C1 subgroups by oculonasal administration of 106 Herts 33 starin of vNDV (Table 1.) by challienging 10 turkeys in A1 and B1 subgroups, and 5 turkeys in C1 subgroup. Results: Used vaccine didn’ ; ; t cause any adverse clinical reaction, regardless the time of exposure to aerosol in SONOVAC 095® ; ; (groups A and B). Developed active immunity to given La Sota vaccine obviously was influenced by vaccination. Compared to the group C, negative control, turkeys that received vaccine responded higher. In a challenged subgroups level of antibodies against challenged virus on 38th day was about twice as high than on day of challenge (28th day) (Figure 2). After the challenge two turkeys in group A died, as well as one in group B, and four in group C. Discussion: Turkeys are less sensitive to velogenic strains of ND virus, never the less they suffer of higher mortality. Therefore lentogenic strains, mainly La Sota, are used to protect turkeys. The vaccine is never given to newly hatched turkeys because of neutralysing efect of maternal antibodies. Obviusly, nebulisation avoids this effect. The mechanism of developed immunity and early specific resistency to challenge infection are not known yet. Nebulization of La Sota strain is a mode of protection against Newcastle disease in all those areas where turkey production is endangered!

nebulisation; La Sota; immunogenicity; newly hatched turkeys

Sažetak je objavljen i u: International Poultry Scientific Forum : Abstracts ; 2003. ; str. 53-53.