They went through the culvert! These cows were pasturing in a field across the road from the barn. We drove by late afternoon, and I guess they figured it was time to go to the barn for milking so they were all making their way through the culvert. No encouragement was needed by a person . They knew the drill.
Here they are coming out the other side.
As they made their way up to the barn, a few of them stopped to say hello to the horses.
I blew this picture up so I could see the horses better. It looks like a mom and her baby. The baby is curious, and mom appears to be chewing on the fence post. Maybe they come over to the fence every morning and afternoon to say hi to the cows.