The prisoners would have a sense of worth and would also need to use computer and other skills to deal with the administration.
Contact with animals is beneficial for most people. Prisons often have a large amount of land and a lot of people with time on their hands. Animal sanctuaries are often short of money, help and space. Why not let prisoners look after unwanted animals until they can be re-homed. They would pick up useful skills, and enjoy the unconditional affection provided by the animals.