You buy Land-o-Lakes butter at Kroger, right? Pretty good stuff. A move up from the colored whipped partially hydrogenated vegetable oil (i.e., flavored Crisco) you ate in college. Butter is made from cream, which comes from the milk of dairy cows. So far, so good.
What sort of drugs were those cows treated with? Antibiotics get into the bloodstream of cows, and thereby into the milk. Low-level antibiotic exposure can result in the build-up of antibiotic-resistant bacteria in humans.
What sort of pesticides or herbicides were used on grain fed to the cows in the milk factory? Many herbicides such as picloram (Tordon, Grazon, or Pathway) and clopyralid (Stinger, Curtail, or Transline) are classified as organochlorine compounds, and are highly persistent in the environment and poorly metabolized by cows and humans. Most organochlorine compounds are fat soluble, and hence can be concentrated in milk. The dung of animals fed picloram-treated grass has herbicidal properties, and can't be used on gardens. That is incredibly screwed-up.
How were the cows that provided the milk for Land-o-Lakes butter raised? Outside eating grass? No. Wrong. How about in a barn on a concrete floor eating grain and being milked to death? Just like all other commercial farm animals. Maybe this makes you say "whatever." Maybe you don't know you have alternatives.
Snowville Creamery. Read about their products. These guys make fabulous milk and cream from grass-grazed cows, so fabulous that it is the only milk used in Jeni's Ice-cream. (I pity you if you've never tasted her ice-cream.) Snowville makes a heavy cream that is unbelievably rich. It is light yellow in color, and sometimes the butterfat solidifies in the milk when it is refrigerated. It is the definition of quality.