The most common grease used is lithium based. For my trailer wheel bearings I usually use Lucas Red 'N' Tacky as it is also lithium based and mixes well with other grease of that type.
Contact the manufacturer if you have concerns to get the exact grease used, but don't be surprised if they can only tell you the type/certification.
With new trailers, I usually immediately clean out OEM grease and pack by hand so that I know it is done correctly
Everyone has their favorite grease, so you may get lots of suggestions
Bottom line is type and certification requirements. After that, it is just personal preference. The most important factor is that you actually repack bearings
__________________
Scott and Liz - Southern NM
2012 Wildcat Sterling 32RL - w/level up (best option ever)
2007 Chevy 2500HD Duramax
Reese Fifth Airborne Sidewinder