Today, the Animal Legal Defense Fund in the United States has ranked the states in order of animal rights.
Although I am sceptical of the arguments of extreme animal rights advocates, I understand that at least in hotter climates with poorer soils there certainly is need for restrictions on animal killing and possibly even on use in some cases (which probably are not found in most of the Western Hemisphere). Nonetheless, the soil map below, which shows lower-fertility and older soils in the South and nutrient-poor parent materials in the central west coast, does suggest that these hotter regions need more regulations on animal use:
In general, the best animal protection laws would be needed in the low-nutrient Southern states and perhaps in the “southwest” (which ecologically includes California and Oregon as well as the states of Arizona, New Mexico, Utah and Nevada normally known as the “Southwest”). As can be seen, some of the relevant states, like Oregon, California, Arizona, Louisiana and Florida, are in the top third, but on the other hand New Mexico, Alabama and Mississippi have laws relatively much poorer than would be required. At the same time, numerous Northeastern states like Maine, Michigan, Illinois, Indiana and Massachusetts are relatively overregulated.