Since the 1950's and 1960's seedstock and commercial cow herds have used a scale to evaluate the individual performance of animals in their herds.
At first, the weights taken at weaning were actual weights without any standard age like 205 or 210 days. The age of dam and sex of the calf were not considered according to Eldon Cole, livestock specialist with University of Missouri Extension.
"It seemed the important thing was to know what the actual weight was and use it to impress neighbors and perhaps potential customers," said Cole.
Over the years, various groups made progress in standardizing the weights to 205 and 365 days of age. Contemporary groups were promoted to compare calves or yearlings more accurately to other progeny within the herd.
According to Cole, herd ratios were becoming accepted as the best method to get a quick snapshot of whether an animal was average, above or below.
A weight ratio of 100 percent indicated an average animal while larger numbers showed above average growth within the herd. Ratios below 100, of course, were those with below average performance.
"These ratios are still valuable today in genetic evaluation within a herd under comparable genetic and environmental conditions," said Cole.
A most probable producing ability (MPPA) was adopted as an excellent cow herd selection tool. The MPPA uses weaning weight ratios and numbers of herd records to accurately compare cows of varying numbers of records.
In the early years, computation of data was handled by University Extension programs and beef cattle improvement association's (BCIAs). Breed associations gradually entered the picture as calculators of performance data at least for registered cattle. Some computed data also existed for commercial herds.
As bred associations climbed on-board, the performance evaluation efforts evolved thanks to computers, into estimated breeding values (EBVs) and expected progeny differences (EPDs).
"This enabled cattlemen to make herd comparisons more accurately than previously," said Cole.
Many of the EPDs and within herd comparison begin with an individual weight written down on a report sheet or entered in a computer.
"In spite of the simplicity of weighing an animal it's amazing how few cow herd owners develop a performance program that involves individual weights. The major excuse is not having a scale. This might be a good time to invest in a scale," said Cole.
Cole notes that the current cattle market indicates the value of one big steer calf or yearling could pay for a scale.
"If you only have a few cattle, perhaps consider buying a portable scale with a friend or neighbor. If you have a scale, you'll be pleasantly surprised at how much you use it for more than genetic evaluation," said Cole.
Source: University of Missouri Extension