Newcastle disease vaccine virus I-2 fails to acquire virulence during repeated passage .

This study determined whether the naturally attenuated, thermotolerant Newcastle disease vaccine virus I-2 could acquire virulence after five passages through SPF chickens. Study design was to international requirements including European Pharmacopoeia, Ph. Eur.

Enterococcal-related vertebral osteoarthritis in South African broiler breeders: A case report.

Infections in broilers and broiler breeders by Enterococcus cecorum, causing clinical disease, have increasingly been described in various countries in the Northern Hemisphere over the past decade. This case report describes an outbreak of enterococcal-associated vertebral osteoarthritis (EVOA) in male broiler breeders in several flocks in South Africa. Male birds aged 4 and 9 weeks displayed the common presentation of lameness, paresis or complete paralysis.