The word "kend" was used as a form address, mostly in rural Hungary, until the early 20th century or so. We're still familiar with it, mostly through 19th century literary works. It is a radical shortening of the word "kegyelmed", which literally translates as "your mercy", so it's a bit like "Your Honour" in English.
As for the "cow" meaning, I have no clue. Could you please give us some context or background information?
(Note that "Kende" is a Hungarian male name of Old Turkic origin.)
1. kende, or kündü: a Turkic origin word, a title of pre-christian Hungarian rulers in the 9-10th century. Soon fell out of use (i think etymologically derived from Turkic "gün/kün"="sun").
2. kend: a form of address, the shortening of kegyelmed, from the early-modern period, first attested in this shortened form in the 16th century. Originally used to address higher ranking persons, but by the 18-19th century it just became a formal pronoun mostly used in the country-side. Also obsolate.
I am not aware of any similar sounding word for cow.
I am afraid I cannot tell you more as for the extra meaning. I had a talk with a translator on the train, and she referred to the historical meaning, which you confirm indeed, but then I think she said the word is still used but in a negative sense: that you can call someone a piece of cattle or something the like, using the same work??? It cannot be the same word then, can it?