Predicting Mature Weights

[tonyb]

A few questions about growing calves for beef:

1. Are there any rules of thumb for estimating mature weight in calves?
2. What is the normal age to start weaning calves?
3. If a cow raises a weaned calf at 50% of her weight, how much could it weigh at one year? How much could it weigh at finish?

I'm not sure if these are impossible questions to answer; just looking for generalities. For the sake of conversation, maybe assume a common British breed like Angus or Hereford (unless breed doesn't matter??), 1100 lb cows, moderate sized bull...

[ramiller5675]

The mature weight of a calf is going to be determined by the weight of both the cow and the bull.

You can wean a calf at about 3-4 months if you have to, but I typically wean at about at least 7 months. It all depends on how much grass you've got left, what the cow looks like, and what the market wants.

A steer will grow quicker than a heifer. A healthy heifer should hit about 65-70% of her mature weight at about 13-15 months. So, a heifer that will be about 1100 lbs. at maturity should be at least 750 lb. at around 15 mo.

Steers grow a lot quicker and are fed differently than heifers, so depending on what kind of feed/forage is available, a steer will either be a little heavier or a lot heavier than a heifer of the same age. And, a steer isn't finished at a certain age, he is finished at a certain weight. When he is getting close to 90% of the weight of the cow, he is just starting to get finished. So, a steer from a 1100 lb. cow might be finished at 1000 or even higher depending on how much fat you want..

[Bret]

I have a target weight for the few steers I produce. I use a weigh tape from Tractor Supply. By putting the tape around the body(not mine) just behind the front legs and measuring in inches, then comparing to the three body types, you can get a close idea.

[Wanda]

The biggest variable is nutrition of the cow up until the calf is weaned and how the calf is fed. This can be used to your advantage to achieve a larger or smaller mature weight.

[CIW]

If a cow doesn't wean 50% at 240 days, she probably is too expensive to keep, and should be looked at for culling.
If you can't get 3.6 lbs. per day gain weaning to processing, that cow (second calf and beyond) should be looked at for culling and you should rexamine the statistics from the bulls that you're using. There are some breeds; Maine Anjou, Red Angus, Limusine and Black Angus that are showing daily average feedlot gains of over 4 lbs. daily. In thier steers.
Heifers will usually run about 3% less than steers on a similar ration.
That being said. replacement heifers that are grown on the slender side tend to mature faster, have healthier lives and have less problems catching in their first cycles. The other side. Fat sells.
Breeding before 2 yo. can put off final mature size and/or even stunt final size.
There are alot of variables that will add or subtract from this. Just a general overview.