Annemarie Schimmel in "Die drei Versprechen des Sperlings" says that the Arabic term for extreme hunger is ju' al-baqar, literally "hunger of the cow". She explains that the cow symbolizes insatiability and quotes a poem by Rumi: There is a small green island where one white cow lives alone, a meadow of an island. The cow grazes until nightfall, full and fat, but during the night she panics and grows thin as a single hair. "What will I eat tomorrow? There's nothing left!" By dawn the grass has grown up again, waist-high. The cow starts eating and by dark the meadow is clipped short. She is full of strength and energy, but she panics in the dark as before and grows abnormally thin overnight. The cow does this over and over and this is all she does. She never thinks, "This meadow has never failed to grow back. What should I be afraid every night that it won't?" The cow is the bodily soul. The island field is this world where that grows lean with fear and fat with blessing, lean and fat. White cow, don't make yourself miserable with what is to come or not to come.
The ancient Greeks had the same word: boulimia, again: "hunger of the cow". It's not a poetic metaphor, but e.g. sober Xenophon uses the term when his soldiers are too hungry to march on, Anabasis 5.4.7.
Strange that they both independendly picked the cow - and not the wolf or the locust or fire or whatever. Does anybody know why this is? And how do you say in your languages?
Maybe "cow" is just used to intensify the word that follows? Cf. German "Schweinegeld", "Schweinearbeit" etc. - literally "money of the pig", "work of the pig" - just means "a lot of money, work". Of course, this explanation doesn't satisfy my cow-hunger for stories.