Why are these men being trampled by cows?

It's a ritual called "Gaay Gauhri" that's practiced in the Indian state of Madyha Pradesh the day after Diwali, the Hindu festival of lights. Men lay on the ground while colorfully decorated cows run over them.

The ritual is believed to bring good luck and prosperity, and any injuries sustained are treated with cow dung and urine. Cows are regarded as sacred by Hindus, with this ritual meant to be a form of sacrifice to the animals.