Opponent AI had a Deepgaze Acolyte and a Gem Feeder out. He attempted to shift the lifedrain from the Feeder to the Acolyte. In response, I Polymorph: Beast the Feeder, and it turns into an untamed duskwing. The Acolyte still got +1/+1, though no lifedrain was transferred.

An intuitive reading of the card suggests that no ability was shifted onto it, just like no battle takes place if one troop leaves play.