I have a large free-range organic flock of chickens, its basically a grain based feed that's made into pellets but it also has some not so nice ingredients. Personally I wouldn't feed it to snails or my hens so I make my own mash rather than use a commercial one.
The reason its called mash is because originally it was a soaked mash that was made to feed chickens etc, these days a lot of people feed it dry.
Some of the ingredients in these pellets are questionable though as they often contain chicken derivatives and bulking agents as well that no normal person would feed any animal. Think back to the BSE incident in the UK to understand some of the effects and implications of feeding animal derivatives of the same animal back to living ones.
Some of the additives I also would be worried about feeding snails as it may well harm them as well as the fact that these commercial feeds are wheat/ grain based and there have been problems feeding these things to snails from what Ive read on some posts on this forum. Personally its easy enough to make up a snail mash mix and you can keep it in a dry container and soak a small amount for use when you want it. That's what I do.
x1 Tiger snails x2 Albino Achatina Albopicta x3 Achatina Albopicta x2 Achatina (Lissachatina) iredalei x6 Albino Achatina Reticulata x4 Achatina Immaculata Immaculatta x6 Limicolaria Numidica x6 Limicolaria Flammea x12 Macrochlamys Superlita x8 Rodatzis / Jadatzi x5 Archachatina Marginatas ( The Bulldozers + a herd of young ones) x11 Helix Lucorum x30 Arianta Arbustorum (and ? many hatchlings n young) x125 Cepaea hortensis and Cepaea nemoralis