First off where do you live, did you build the pond, how big is the pond, how deep is the pond, how is water fed to the pond and what is the pond lined with or is it dirt?

These are all questions that need to be answered before a educated guess can be given on raising shrimp.

Don't forget that birds feed on anything aquatic so you will have to have a way of keeping them at bay.

As for the food, in a seasoned dirt pond, you would not have to feed the shrimp much of anything as they will live off the aquatic critters in the water and mud. Otherwise I agree with Keith_r on food.

Also remember that prawns are aggressive and territorial and need lots of room or they will kill and eat each other.

Also Tilapia are carnivorous during adolescence and will readily kill and eat your shrimp.

If your are in a state that allows Australian Red Claw Crayfish, they would be a better choice to raise.