Can partial points be transferred to Silversea?

No.  If you sail with Royal Caribbean or Celebrity Cruises and want to apply your earned points to Venetian Society, you must qualify for at least 1 VS Day to be eligible. Partial VS Days will not be awarded. 

For example: An inside stateroom on a 3-night Royal Caribbean cruise, translates to only .75 VS Days and therefore cannot be transferred to Venetian Society.