Kirkland is a step WAY down in quality from Innova. I do not understand why you would go down? The vet bills will go up, if you go down in quality.
If they are not as excited about eating Innova....try them on the Healthwise (made by Natura also). You could also go to another good quality food such as Canidae or just add a tablespoon of some canned dogfood. This often perks appetites up.
Kirkland is not a terrible food....there are alot worse foods . I would put it on the same level as Nutro Natural or ProPlan. When we go to Costco I see people buying 5-10 bags at a time...probably breeders feeding multiple dogs. If I had to feed 10 dogs, I maybe would feed Kirkland and add some extra meat and supplements.
Gina