That depends on a lot of things: her diet, physiological, psychological, sociological, reproductive needs. Examples:
- A cow in heat would crave a bull.
- A cow that has a diet that is poor in phosphorus will crave phosphorus by eating wood.
- A cow that has been separated from the herd will crave having company or her herd mates back.
- A cow that has been eating dry feed for a long period of time will crave water.
- A cow in a frightening situation will crave to get out of it as soon and as fast as possible.
