Meat prepared with Fleischsaftgarung is not only easier to digest, but it also increases the usable energy content. This is because proteins denatured by heat can be digested more quickly and converted into energy more easily. This applies to both humans and animals.*
*Source: "Energetic consequences of thermal and nonthermal food processing", Rachel N. Carmody et al.; Proceedings of the National Academy of Sciences (PNAS), doi: 10.1073/pnas.1112128108