Understanding aAa® and Weeks® Analysis Numbers

For a cow, aAa® and Weeks®  Analysis numbers show the qualities she needs, in order of priority, from left to right. The numbers 435, for example, show that a cow needs  aAa® and Weeks® qualities 4 Strong, 3 Open, and 5 Smooth.

For a bull, aAa® and Weeks®  Analysis numbers show the qualities he adds in a mating, in order of priority, from left to right. For example, the numbers 435216 show that a bull adds  aAa® and Weeks® qualities 4 Strong, 3 Open, 5 Smooth, 2 Tall, 1 Dairy and 6 Style.

Closely matching a cow’s aAa® and Weeks®  analysis numbers with those of a bull will increase the odds of improving the next generation and of getting an above average daughter of the bull used. For example, when a cow is analyzed as needing  aAa® and Weeks®  435, Strong, Open and Smooth, consider using bulls with aAa® and Weeks® 435, 453, 345, 432, 543, 354, or 534 as his first three numbers.

From its initial introduction until the present day, the principles of aAa® and Weeks® Animal Analysis have never changed, although the format has been simplified and refined. As his own experience evolved,  Bill Weeks simplified his original “round and sharp” analysis into the six aAa® and Weeks® numbers we know today:  1 Dairy, 2 Tall, 3 Open, 4 Strong, 5 Smooth, and 6 Style.

Bill Weeks  stated that these six numbers and the qualities they represent are of equal importance and they are all essential to the vital functions and performance of a dairy cow. The ideal dairy cow would achieve a perfect balance of these six qualities. Each of the six qualities is a combination of positive characteristics. Dairy breeders can bring these qualities and characteristics into balance by using the information provided by aAa® and Weeks® Animal Analysis.