Content Creation for Second Life and OpenSim

Can content such as meshes, and animations, be created in UE4 for use in Second Life, and OpenSim, grids?

UE4 is a game engine so it would be quite odd tom make something in one engine to import into another. I think you are looking for 3D modelling programs such as 3DS Max, Maya, Blender, etc for making meshes, animations, etc.