I can attest to the idea that butter has varying flavors from season to
season: I live in Cow Heaven on the north coast of California---a place
of wide green pastures and tiny daisies where the cows have fed for more
than a century to make high butterfat content milk. I sometimes make my
own butter from local cream (shaken in a mayonnaise jar) The butter from
that milk certainly does taste like the local fields, and it changes
with the seasons.

phbp