What does all of this mean? You can print this if you like, it is a decent reference.
Moisture:
is amount of water we are paying for. If the number was 0 you would be buying ashes. If it was 100 % you would be buying distilled water.
Crude Protein:
is the amount of protein in a crude form. The fish must digest it for it to become usable.
Digestible Protein:
is the amount of protein that is considered by-pass protein or readily assumable by the fish. The higher the digestible protein levels are the less the fish has to work to digest it. Leaving more energy for growth, reproduction, respiration, etc...
Crude Fat:
Is the amount of fat in the diet. This is also a measure of the amount of Essential Fatty Acids (EFA's) in the diet, not just fat. EFA's are just that, they are essential. Diets that are 8% and higher are considered "high fat diets". They are more expensive to produce, and have a higher efficiency rating. More fish from feed, as apposed to more waste from fish.
Crude Fiber:
This is the portion of the food that aids in digestion, just like with us.
Nitrogen Free Extract (NFE):
Defines the amount of carbohydrates and sugars that are present in the diet. The carbohydrates and sugars are important for proper function of the internal organs, reproduction, energy etc. Too many sugars and your fish act spastic just like a kid after 2 sodas and couple of candy bars. Too many carbohydrates and the fish will begin to store fat, Fish do this just behind their gills along the body. It kind of looks like they have big shoulders. Some plant starches are in this category and cause fatty liver disease in some fish species.
Total Digestible Nutrients (TDN):
Defines how much of the feed blend is actually biologically available to the organism. The rest is considered waste. i.e. If a competitors fish food has a TDN of 45% that means that there is 55% of the food that is not usable to the fish. So for every pound of fish food you put into the tank you are guaranteed at least .55 lbs of waste. That is part of fish keeping that is not so much fun.
Ash:
Shows how much of the waste in the feed is ash or cooked to hard to digest. If a competitors fish food has a TDN of 45% that means that there is 55% of the food that is not usable to the fish. Or .55 lbs of waste from every 1 lb of food. The ash is waste and is part of what is not covered by the TDN.
Calcium:
Best noted for strong bones and good growth rates. Needed in metabolic functions.
Phosphorus:
Phosphorus is a key element to proper fish growth, too much is waste and aids algae growth. Generally fish foods that are near 2% are considered low Phosphorus foods. Fish foods that are naturally low in phosphorus and high in fat are difficult to find, formulate, and procure with normal financial means.