Dry or wet? Some of the dry Blue formulas are a bit short on protein; 30% is a rock-bottom minimum for a regular diet.
I recommend no dry food for any cats, but if you must feed dry, it shouldn't make up more than half of their total diet. This food is okay as far as dry food goes, but it is high in carbs, about 40%.
You should at least switch dry foods every 3 months, though, to prevent allergies and other problems. Here's more on why and how to make the switch: http://www.littlebigcat.com/index.ph...switchingfoods