It's aimed at dairy cows, so they'd be herded in for milking twice a day anyway. Though having said that, the cows on the farms near where I grew up would line

It's aimed at dairy cows, so they'd be herded in for milking twice a day anyway. Though having said that, the cows on the farms near where I grew up would line themselves up at the gate to be milked, and one farmer would just open the gate while another shooed the stragglers back towards the herd. If this thing is anything less than 100% effective it doesn't seem like it would save much work, since you'd still need someone on a quad bike to deal with the nuisances.