Just don't. If it's the ones I'm thinking of they've got "oat feed" and "wheat feed" in them. I believe nuggets should be hay based. We don't recommend these at the rescue where I volunteer. That said if it's the only nuggets you can get I suppose at least they won't starve. But there are better nuggets out there to feed, it all depends on your budget I suppose. The better nuggets you would only need to feed an egg cup of nuggets per piggie a day.
ive observed the science selective non grainless 1st ingredient is alfalfa meal,whole wheat and wheatfeed.this costs £22.00 for a 10kgs bag.i feed a selection of pellets,Harringtons,burgess excell origano and blackcurrent.science selective,science selective grainless.it depends on your budget and what your piggies will eat !