When you want your lion to try something different, you can try this. Make sure he's a little hungry, and will have himself worked up into a kind of feeding frenzy. Give him one silverside, maybe cut into a smaller portion than usual. Then, try giving a piece of something new you want him to try. "If" he takes it, then for the third piece of food, go back and give him another piece of silverside. Watch the portion sizes so you're not overfeeding though. Patience and persistance. Eventually he may learn to eat just about anything you give him. At least that worked with mine. As far as adding a trigger? I've read that sometimes they may nip at the fins of a lion. Maybe someone else will jump in and help or give you more ideas.