Goldfields, if it is your first bag it can be very hard to tell good from bad, for a human. I went through something similar many years ago with a different brand - The new bag contents looked different, smelled different, but to us not bad, so
we served it anyway, they grudgingly ate it, and we ended up at the vet for belly aches with a lesson learned the hard way, and as much at their expense as ours. Listen to the dogs.