These results suggested SD9902 stain of ALV-J was an acutely transforming virus, but SD9901, YZ9901 and YZ9902 stains were non-transforming viruses.

• 其馀3株病毒感染的肉用型鸡无肉眼可见的肿瘤性变化，生长和临床表现正常。显然，SD9902株ALV-J为急性转化型病毒，而SD9901、YZ9901和YZ9902这3株病毒仍属致病性较弱的非转化型病毒。