If you absolutely cannot find the information by googling, you can do a pretty good calculation on your own simply by knowing the fat concentration of the feed. Fat has 9 calories per gram; protein and carbohydrates have 4 calories per gram. There are 453.6 grams per pound, and from there, you can figure out roughly how many calories per pound.
The one caution there is how to treat fiber content. There are differing opinions on how many calories the body can extract from fiber, so when I'm coming up with rough estimates, I typically just use 2 calories per gram for the fiber content.