Deciding when to harvest steer is part science, part art and plain old luck

SPRINGFIELD, Mo. – How do you determine when to harvest steers that have been on feed? That’s a tough question to answer with a real specific guideline, according to Eldon Cole, University of Missouri Extension livestock specialist located in Mount Vernon.
“There are many subjective and objective measurements, old wives tales and observations. Plus, we always factor in prospects for a price rise or decline along with gut-feeling notions.
“It sure isn’t an exact science made simple with pop-up timers, like there are in turkeys which tell you when they’re done,” said Cole.
Frame size. One of the guidelines that helps pick the proper endpoint is frame size. The government grades for feeder steers are broken into large, medium and small frame sizes.
Theoretically, the large-framed steers should reach 1,250 pounds and more before reaching the Choice grade. Medium framed steers should reach Choice form at 1,100 pounds to 1,250 pounds, while the Small framed feeder steers would be ready for harvest under 1,100 pounds.
Using the more specific frame score chart, the large cattle have frame scores of 5.5 and up while the smalls are 4.5 and down.
Marbling. Even within frame sizes, genetics play a big part in fat deposition.
“The ideal genetic package will have cattle deposit nice amounts of intramuscular fat, which is referred to as marbling, with fairly small amounts of outside fat cover. These fat deposits are difficult to determine visually so cattle feeders resort to other indicators,” said Cole.
Among the visual indicators, Cole said fat shows up in the scrotal area (sometimes referred to as the cod), the brisket, the flank and around the tailhead.
A keen eye will detect differences that indicate the steer is ready to harvest without being so fat as to fall into a Yield Grade 4 carcass.
“If cattle are being run through the chute for a check weigh, some persons have an ability to palpate fat thickness over the loin and rib area and predict fat thickness amounts,” said Cole.
According to Cole, a growing number of lots use ultrasound to estimate both marbling and external fat.
“These objective values are certainly more accurate at predicting carcass merit than the naked eye,” said Cole.
Rate of gain. Two other points that feeders may consider are rate of gain and feed intake.
Some feedlots track rate of gain at various stages of the feeding phase. When growth rates drop below 85 percent of their first 90 to 100 days’ gain, the cattle are considered ready.
Monty Kerley, a University of Missouri beef researcher, said in feedlot studies when cattle gains for the previous three week period drop below 2.2 per day, they go.
Part of this slow up could be related to a reduced feed intake that shows up as cattle approach their endpoint.
Cole said that with $3.50 to $4 a bushel corn, cattle feeders are anxious to keep their lots current and market cattle when 60 percent to 70 percent appear to be able to produce a carcass that grades low Choice or better.
Genetics. Some marketers may choose to feed cattle for longer periods, hoping to capitalize on the premium Choice markets such as Certified Angus Beef.
However, Cole feels that unless you know the genetics behind the cattle, putting an extra 30 days of feed in them may not be that profitable because they may not marble sufficiently to make average Choice and higher.
“There’s a little art, some science and a lot of luck in striking the happy balance to achieve the optimum quality grade, yield grade and feedlot profitability when feeding out cattle,” said Cole.