Final answer:
To stimulate urination in cows, the method of gently rubbing dry hay ventral to the vulva in a circular manner is used. This acts as an external stimulus to prompt urination.
Step-by-step explanation:
The method used to stimulate urination in cows is gently rubbing dry hay ventral to the vulva in a circular manner. This process can act as an expression by an external stimulus which mimics the sensation that might prompt urination.
While this method is about stimulating urination, it is somewhat analogous to other animal handling practices such as the "ram effect," which is used to induce ovulation in ewes by introducing a ram into the environment, inciting physiological responses through external stimuli.