Flat Water Gang Red Angus

Ross Knott


Ben Cooksley

The Cornerstone Cow

The Cornerstone Cow program is a tool for producers to utilize when selecting seed stock for their operation. The
word cornerstone is an architectural term meaning the first stone set in construction. The stone on which all the
building depends. For our purpose, the Cornerstone Cow is a measure of the following:





This scoring model ranks the components of fertility, production to weaning, and longevity, within a herd and age
group of females. The categories being scored are based on the actual data submitted to the American Red Angus
Association as a part of total herd reporting. Any cow scoring 90% or higher earns the title of a CORNERSTONE COW.

By scoring our cow herd we are attempting to provide you with an easy-to-understand value for each female in our
herd. The Table below summarizes the scores for each age group of cows in production:

Age of FemaleBest Possible ScoreTop 25%Top 50%
9 + years old3526.2517.5
8 years old3324.7516.5
7 years old3123.2515.5
6 years old2921.7514.5
5 years old2720.2513.5
4 years old2518.7512.5
3 years old2317.2511.5
2 years old2115.7510.5

Genetic Information


MOST PROBABLE PRODUCING ABILITY (MPPA) – An estimate of a cow’s future productivity for a trait (such as progeny weaning ratio) based on her past productivity. For example, a cow’s MPPA for weaning ratio is calculated from the cow’s average progeny weaning ratio, the number of her progeny with weaning record, and the repeatability of weaning weight.


The amount of time (days or months) between the birth of a calf and the birth of a subsequent calf, both from the same cow. *Calving interval of 368 or less is assigned to Donor females that are 6 years old and older. **Calving Interval of 376 to 397 is assigned to Donor Females that are 5 years old and younger.


The difference between the birth weight ratio within a known population to the weaning weight ratio within the same population of individuals.
The ratio change for this measure is the difference between the cow’s actual average birth ratio of all her calves and the weaning ratio of all her calves.


Cows can live for over 20 years, but on commercial farms, the age
at slaughter varies considerably. Farms with poor management, high-yielding
cattle or high disease rates will slaughter their animals at a much younger age,
normally after four lactations (around 5-6 years old), but sometimes after 2 or 3.
Cows should be able to consistently breed and rebreed through about 8 years of
age and performance should be maintained until around 12 years of age, that is
when you might see a steeper decline in reproductive performance.


These are the calves that are conceived either by artificial insemination or natural service. These calves are carried by the dam and raised by the dam within the population of the operation. The number of natural calves is an indicator of the cow’s ability to raise a calf and rebreed within their environment over a longer period.

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