In reality, there's no real reason for calves (other than those born to milking dairy cows) to ever nurse a bottle. It's MUCH more efficient to make sure calves stay with their mothers and just get their milk from the source. Bottle feeding takes time. It requires that the milk be refrigerated, then warmed again before the evening feeding. And it must happen at least twice a day until calves are a few months old.

But in most herds, there are a few misfits....such as those calves whose mothers don't tend them and so fall behind nutritionally. As well as the calves too weak or -- I'll say it -- stupid to keep up with the herd. And, sadly, calves whose mothers somehow die before they're big enough to be weaned.

These sorts of calves usually start out completely dependent on their human surrogates. They bawl when they get hungry. They nuzzle your legs, smelling milk and the bottle nipple. They stick out their grey noodley tongues. They'll follow your voice from 500 yards.

If you're lucky, you'll have real, fresh milk on hand. We're usually milking a dairy cow for our personal use, and the excess milk goes to our chickens, dogs, cats, pigs, and/or bottle calves, depending on which we have on the farm at the time and which need the supplementation the most.

Just when you begin wondering aloud -- after, say, several weeks of this twice-a-day-ness -- why you ever thought calves were cute, your darlings will hit their tweens. They get just big enough to push you around when the nursing isn't going precisely their way. They head-butt the bottle and each other, hoping to wrest more milk from the "udder." They suck on each others' ears and, if anatomically available, other private parts. The stronger ones strong-shoulder the weaker ones.

And so it comes time to train calves to drink from buckets. 

The first day is a rodeo. There's the matter of catching a calf's head between your legs, wrangling him/her to a bucket, and pushing his/her nose into the milk. He/she will sputter, thrash backwards and forwards, bawl, step on your feet, butt you in the groin, and splatter milk inside your boots.

The next day usually involves the same, with some leeriness thrown in -- a new emotion for calves of such straightforward existence.

And then it happens. You pour milk in one bucket, and as you're filling others, a calf will find the first bucket and drink, without coersion, without a fuss of any kind. And he/she will raise his/her head from the rim, milk froth dripping from the wiry hairs of his/her muzzle, blink blithely, slurp again in a very grown-cow sort of way, then saunter off, like a kid who's used a vending machine by his/herself without help, with correct change, for years.