I think I have another reference. Weren't there cows in The Killing Fields (1984)? IIRC, Dith Pran (the Cambodian journalist) hid out from the Khmer Rouge in a livestock pen that had some cows in it.
Luis Buñuel - L'Age d'Or An everyday event, finding a cow in your bed. A cow's body part also makes an appearance in Un Chien d'Andalou. I won't post a picture, but the famous eyeball is actually a cow's.
When they released it in France, they had to rename it because there wasn't a comparable French idiom for the term 'city slickers.' It was renamed La Vie...L'amour...Les Vaches. ("Life...Love...Cows".)