I'm not familiar with ,Nutri source, but some other good foods are Go Natural Grain Free, and Avoderm, but I'm not sure if they have a chicken free formula or not. I switched to Fromms Beef Fritata, when my 2 were 7 months old, they had been on Royal Canin from the breeder, then I switched to Go Natural, but my female Blossom didn't tolerate it very well, so I switched back to Royal , then to the Fromms Beef, while I was switching and researching and trying foods, I did notice that most of the higher quality foods, like the 6 star rated ones were all similar in price, there wasn't much of a difference, but I also noticed with these foods that they have less poop, and less smelly stools, which means they are probably digesting more of the nutrients they eat, and getting more nutrition from its. Also because its better quality , you don't have to feed as much, and therefore save there as well. I figure if you feed a better quality food to your babies, you will save money in the long run, in vet bills due to better health, and your bully will be healthier and live longer. I compare it to us as well, if we eat better and healthier foods, we will be healthier in the long run, and if we buy better quality, like organic foods, we will reap better health in the long run.