Easy, nanobots that will create a projection preys and once their predator captures them, the projections will turn into their respective food source. The predator still have the illusion that its capturing something, but no consciousness actually suffers.

Or even better, the button will move every conscious being into their own universe where they are the only conscious being. The process is perfect and the being cannot observe any difference. Each of these world progress in parallel (does not diverge) and therefore all beings existed in a world where they would have existed. Except no being is suffering.

Edit: Also, just because they need to eat the way they do does not mean that it is still not suffering and is therefore a moral bad. Why can't animals be "wrong"?