I have fed Mazuri for 6ish years with no problems. However, as my #s of chins has increased and rescues have come in, I have noticed that a few have had soft poos. Switching them to Oxbow has alleviated that problem. I currently have 5 chins on Oxbow and 12 on Mazuri. I'd like to switch them all to Oxbow eventually, if I can find a 25 lb bag for a reasonable price. So my answer is Oxbow (sorry to have rambled on...lol).