Hey Phio, no this doesn't oxidize on me, although to be honest, very few formulas oxidize on me. (mostlysunnyblog.com)
Also, very few formulas contain mainly meats in the first ingredients, they usually contain vegetables, potato, tapioca or similar, so the real percentage of protein in canned food is not high. (catfooddispensersreviews.com)
There are a few formulas to find breakeven, but an easy one simply divides your costs by your percentage rate of gross profit. (entrepreneur.com)