Have you ever looked at the label of a can of pet food and wondered why the guaranteed analysis of their nutritional content is so different as compared to their dried counterparts?
For example, the protein level in canned food typically seldom exceeds 10% whereas dried food typically has 20-30% protein.
If so, is canned food less nutritious?
The answer is quite simple if we think about it. The main difference between wet food and dried is as the name implies, the moisture content. It’s just like a tablet of vitamin C into a glass of water. In its concentrated form (tablet), there’s 1000mg of vitamin C and even when it’s dissolved, the amount of vitamin C in the solution is still the same.
Therefore, to make meaningful comparison between wet and dried food, we have to remove their moisture content through calculations and compare them on a “dry matter basis”.
Let’s say you want to calculate the protein level of a particular brand of canned food which looks like this:
- Crude protein: 10%
- Fat content: 8%
- Moisture: 80%
If we were to remove all the moisture, we would be left with 20% dry matter (100% minus 80% moisture). To find the amount of protein (or any nutrient expressed as a percentage) the dry matter has, divide the amount of protein by the amount of dry matter, which in this case looks something like this:
10 (Protein level) / 20 (Dry matter) * 100% = 50%
So in this instance, the amount of protein (50%) in this particular brand of canned food actually has more protein than most brands of dried kibbles.
As for dried food, their moisture levels usually hovers around 10-15% and for kibbles with a guaranteed analysis of 28%, you will find that their protein level will be around 30% using the dry matter basis of calculation.
That said, higher levels of protein or fat is not an indication of quality and it all depends on what your pet needs. Pets who are overweight or suffering from kidney problems might worsen their condition if fed on a high protein or fatty diet. Secondly, nutritional analyses is just a reference and again, it does not reflect the quality of the food. Hair, nails, feathers etc. are all sources of protein. That’s why food vastly different in price may have exactly the same nutritional analysis. So don’t be fooled, be informed.