Field evaluation of an orf vaccine in sheep and goat flocks with high neonatal mortality

Abstract

A high percent of annual neonatal mortality attributed to orf infection was observed between 2001 and 2004 in 2 sheep and 2 mixed (sheep and goat) flocks of Northern Greece. In order to protect the neonatal lambs and kids from orf infection a commercially available live orf vaccine was used. Pregnant sheep and goats were vaccinated subcutaneously a month before parturition, while 10 sheep and 10 goats in each flock remained unvaccinated and were used as negative controls. The vaccine was significantly effective (P lt 0.05) in reducing the orf lesions and the mortality rate in lambs and kids of the 4 flocks. During the next year 3 of the 4 flocks were revaccinated. A significantly low percentage of orf lesions and neonatal mortality continued to occur in revaccinated flocks, while a significant percentage (P lt 0.05) of orf lesions and neonatal mortality reappeared in the nonrevaccinated flock. The antibody titres in vaccinated sheep and goats were increased significantly on days 60 and 105 post-vaccination, while the titres in the controls remained low (P lt 0.05).

Visok stepen godišnje smrtnosti neonatalnih životinja doprineo je orf infekcijama uočenim izmedju 2001 i 2004 kod dva stada ovaca i dva mešovita stada ovaca i koza u severnoj Grčkoj. Komercijalno dostupna živa orf vakcina je upotrebljena da bi se zaštitila neonatalna jagnjad i jarad od orf infekcije. Bređe ovce i koze su vakcinisane subkutano mesec dana pre partusa, dok je 10 ovaca i 10 koza u svakom stadu ostalo nevakcinisano i posluž ile su kao negativne kontrole. Vakcina je bila značajno efikasna (P lt 0,05) u smanjenju orf lezija i stope smrtnosti kod jagnjadi i jaradi sva četiri stada. Tokom sledeće godine, 3 od 4 stada su revakcinisana. Nastavljena je pojava značajno niskog procenta orf lezija i smrtnosti neonatalnih životinja u revakcinisanim stadima, dok se ponovo pojavio značajan procenat (P lt 0,05) orf lezija i smrtnosti neonatalnih životinja kod stada koja nisu revakcionisana. Titri antitela kod vakcinisanih ovaca i koza su bili znacajno poviseni 60 i 105 dana posle vakcinacije, dok su titri kod kontrola ostali niski (P lt 0,05).