(This is a copy of our reply to a question about how we rear calves. The post that was being referenced was published six years back.)
Thanks for the question, Nick! Wow, we haven’t looked back at this for a good while, and now it’s six years old. Time to put out a new post on calf-rearing. I’m not sure whether you want information on feeding, or on weaning (from milk altogether), so I’ll put down both.
We haven’t fed grain to any ruminant in several years. Even our lactating dairy cows are all grass, all the time — they winter on stockpiled forage. Our bottle calf protocol (which goes for weaned-rom-mama-but-not-from-milk calves, too, bc. mostly they come off their mamas before we’re ready for them to be weaned from milk, so they go from mama to the bucket) is as follows: newborns stay on mama for eight to twelve weeks, then they go to the bucket, about six quarts per day. Newborns that are bought in get a couple of feedings of saved colostrum, then go to two two-quart feedings of straight cow’s milk per day, but we add an egg, beaten in, into each feeding, as a preventive of scours. After a couple of weeks they are up to six quarts per day. All calves stay on milk for at least fourteen weeks; if there’s a lot of skim milk or whey around, they might get that for a bit longer. They always have access to water and good forage or hay. We take them down to a single feeding per day for about a week before we wean them altogether. When they come off milk, they are on grass alone.
If it’s July when they come off the bucket and the grass is mostly tought and lignous, they are going to be set way back, so don’t do it if you can help it; wean in April or May, if you can, or else when the fall grass starts to come in again.
If they are running with older animals in a rotational/management intensive situation, wonderful, but because competition is intensified in the smaller paddocks, it makes a big difference — on our farm, anyway — that we fence with a single strand of polytwine and just two or three joules on the charger. This means the little guys can slip out under the fence and graze in front of the rest of the group. They get the best forage available, but because they are only a little way in front of the herd, they aren’t doing any harm to the grazing sequence, since the mature animals will graze that spot the next day.
Understand, these are baby dairy bulls that are being raised for a life of grass. You do understand that by weaning from milk at three months we take away the natural advantage of mama’s later weaning (and bigger servings) without compensating for the calories with grain (a food that disrupts the proper development of their rumens). They are going to grow much more slowly than a Hereford calf on grain, silage, haylage, baleage, and whatever else, and somewhat more slowly than a calf that stays on mama for six months. It’s a trade-off, but it works for what we want, which is Jersey beef (delicious) that is all grass with no bought-in supplements.