You're right, it does affect the nutritional value. The exercise that animals can get from roaming outside makes changes to things such as mitochondrial density

You're right, it does affect the nutritional value. The exercise that animals can get from roaming outside makes changes to things such as mitochondrial density of the muscle cells. Diet is also important. We need a wide variety of nutrients for our own cells to work optimally, some of those can be biosynthesized by our food sources if they are given better nutrients (that act as substrate to synth what we need) Just as one example: https://pubmed.ncbi.nlm.nih.gov/21673178/ https://pubmed.ncbi.nlm.nih.gov/21673178/