Moving cattle from the front lets them follow naturally without stress, while starting from the back in a zigzag pattern confuses the herd and separates cows from calves. Front-initiated movement mimics how cattle naturally move together, reducing the confused looking back that happens when animals are pushed from behind.
One thing I discourage people from doing is starting cattle from the back in a zigzag motion. If you're going to try to get herd instinct going in your cows, this causes just enough stress to prevent the cattle from acting as a herd. As you can see from this diagram, As you move the cattle, start the cattle in the back, the cattle go through and around the cattle that are in front of them rather than just starting up from the front and letting it go out as it would if you were sitting at a green light. If you're sitting at a green light and you had to wait for everybody else to pass you up, it would cause you stress. Maybe not a lot, but it would cause enough stress that it irritates you, and that is just enough stress to keep the cattle from acting as a herd. Starting cattle from the front allows them to start naturally, just as they would if they were all leaving the same place, going the same direction on purpose. The front end starts out, they wander off, and the rest of the cattle just follow. By starting from the front, going up the side, the cattle will start lining out and go by you naturally. Cows can pick up their calves, no problem. They're not being stressed because they're being pushed. And this will help you get your herd instinct in your herd versus trying to do it from the back and having the tractor-track effect where the cows walk off and the calves are looking around. Or even your other steers looking around at the back of you rather than just following the rest of the cattle. No pressure.
