From my tests (filling up my inventory with random items, switching to survival an then feeding the cows) it does not.
Yeah, I don’t want to put my whole inventory away whenever I want to feed an animal, but at the same time I don’t want to risk loosing my heavily enchanted weapons and tools.
It happened to me in single player too, in 1.1.5
From my tests (filling up my inventory with random items, switching to survival an then feeding the cows) it does not.