Pigs are ~50% meat by mass, but less than ~0.01% insulin by mass. And animals are pretty well optimized for producing animal bodies with minimal food consumption, so the possible gains are
factor of ~2 from not producing the rest of the animal
Small factor from turning food into meat more efficiently than evolved animals
Small factor from turning energy into food more efficiently than evolved plants
Large factor from producing energy more cheaply than we produce crops for animal feed
Pigs are ~50% meat by mass, but less than ~0.01% insulin by mass. And animals are pretty well optimized for producing animal bodies with minimal food consumption, so the possible gains are
factor of ~2 from not producing the rest of the animal
Small factor from turning food into meat more efficiently than evolved animals
Small factor from turning energy into food more efficiently than evolved plants
Large factor from producing energy more cheaply than we produce crops for animal feed