"A cow is also money. A cow gives milk, meat, skin, and work power. So it is a measure of wealth and can be used to pay with."
Interesting. Reminds me of the Hávamál : "Deyr fé, deyja frændr". The common translation has "cattle die" but I have also seen it translated as "wealth dies". Both in poetry and real life the word has a double meaning. Cows can die and wealth can fade but 'the glory of the dead can live on'.
Also didn't know Rupee and Ruble also came from the words for cow. :-)