My first thought is that they're stealing them. I used to work in an area that had a beef or dairy farm or two and I heard lots of stories (never saw one myself though) of people in regular ol' cars stealing calves. They're worth a considerable amount of money. It's sad.
LOL!! If those are calves, they've got to be almost yearlings, judging by the size of them. Those aren't baby newborn calves! Too wide & too much neck/body fat in ratio to the head size.