Feeding a calf, especially feeding it milk replacer from a bottle or bucket.
I looked through my car window and saw a young calf grazing in the grass.
As much or long as it likes and you want. Seriously, you can have your calf graze as much as you wish or it wishes, it's not like feeding grain to it and risking it getting bloat from feeding too much grain.
It all depends on the breed, the genetics of that calf, the health of the calf, and the quality/type of feed you're feeding it. Thus it could take anywhere from three months to eight to get a calf to be at that target weight.
Milk, and a feed called Calf Starter (or some similar name), which is a formulated feed meant for feeding growing bottle calves.
NOTHING can or should replace Colostrum when feeding a newborn calf. You MUST feed a new baby calf colostrum within 24 hours after it is born. There is nothing man-made or similar than can replace colostrum.
Such a generic term can lead to very skewed calculations as to how much grain is needed to raise a calf to the lucky number 400 lbs. What if that calf is already at 400 lbs and the questioner doesn't even know it? Breed, age, current weight, type of grain being fed and if there is other feed being fed (i.e., hay, silage, grass) are all things that must be known first and foremost before this question can possibly be answered.
A hand-fed calf is called a bottle calf. Yep, you heard me right, just like a baby with a bottle, these little moo-moos get their milk straight from a bottle instead of mama cow. So, next time you see one of these cuties, just remember they're basically the bovine version of a human baby with a bottle.
Pasteurized milk in the form of Homo, 2%, 1% and skim. You can kill a calf feeding that milk to it.
You can start to place grain out for a calf after the first week of age, but they will only take a few mouth fulls each day for the first few weeks. Around 45 to 50 days old they should be actively eating grain.
Baby dugongs are born after a gestation period of about 13 to 14 months. The mother typically gives birth to a single calf in shallow waters, where the calf can easily reach the surface to breathe. After birth, the mother helps the calf to swim and encourages it to start feeding on seagrass, which is their primary diet. The calf stays close to the mother for protection and nourishment during its early months.
Try to give her a kick-start by giving her a shot of Oxytocin (or an injectible hormone that is similar to encourage milk production) to help encourage her to start producing milk. If that isn't effective, cull her. I hope you are bottle-feeding the calf at this time, because the calf is more important now than the cow.
You will want to wean at about 5 months of age, be sure to gradually wean the calf, start mixing more water than starter until they are drinking just water, you can do this for about a week or even two. Be sure that the calf is eating forage and start feeding it a calf starter grain (if you haven't already) it is going to need more proteins than calves raised by their mothers.