Can you explain why the meat allegedly tastes better if the animal is treated better before being slaughter?
The flavor of the meat is altered by the release of stress hormones like epinephrine and cortisol in reaction to “mistreatment.” Build up of lactic acid (the chemical responsible for the burning sensation you get when lifting weights or running) and other metabolites in the muscle tissue can easily alter the flavor of an animal’s meat. Most of these reactions to stress can be reversed over time (your muscles don’t burn forever after exercise), however, if an animal dies while under stress, then the whatever is present in the tissue isn’t going to change anymore. As for the taste, that’s a question of preference. In some Asian countries dogs are stabbed, beaten, yelled at, and a number of other things to stress them out as much as possible before being killed. The flavor of meat this treatment causes is actually considered a delicacy in some circles.
