as Fidget said, since you have it you could give it as a treat if you want and remove the corn to be safe
but there are some ingredients that are not very good so personally I wouldn't buy it, not even for a treat.
Since it isn't organic and the primary ingredient is wheat, it likely contains a lot of GMOs too
personally I would feed the good ingredients as real food .... by that I mean instead of feeding this I would cook a sweet potato and give the ratties some as daily real vegs are important