There are some factors to consider when dehydrating dairy products. Most dairy products are high in fat, making them unsuitable for dehydration. Plus, there is the bacteria factor to consider. They make great cultures for spoilage, so extremely sterile conditions are necessary for safe dehydration.
The most successful dairy product I’ve dehydrated so far is Greek yogurt. Check the page on yogurt to see the pictures of how it turned out.
Most cheeses are way too fat to dehydrate. I tried dehydrating both slices and grated cheddar cheese. Oil oozed out and needed to be blotted frequently. Plus it dried so hard that it simply wouldn’t rehydrate. The grated cheese would not melt in scrambled eggs and was so hard I couldn’t powder it, even by buzzing it in the food processor.
Frankly, I decided that when it comes to hard cheeses for long term storage, it is far more practical to wax them. You can find many links on cheese waxes and instructions on how to do it.
There are people who dehydrate eggs. Personally, I am a little leery about it. the reason is that raw eggs are highly subject to salmonella. Eggshells are porous and easily contaminated.
Commercially prepared powdered eggs are relatively inexpensive, and someone else has gone to the trouble to prepare them.
There are links on dehydrating eggs. Basically, if you are going to do it, you should dry-scramble them. Make sure you use no oils, fats, butter, etc. just cook they plain and dry. Take the cooked eggs and spread them out on your fruit leather trays to dry. You can powder the dehydrated eggs for use in cooking.
Note: as of this writing, I have not tried dehydrating eggs. When I do, I will post the results on how they turned out.