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aAa analysis example for a 4,6,2 cow

Mary Weeks Dransfield Published on 24 August 2015

dairy cow

This cow’s functional problems are lameness and high SCC. Her daughter will function better than she does if the sire brings aAa qualities 4 - Strong, 6 - Strong, 2 - Tall to the mating.



A cow with aAa quality 4

When I look at this cow, I see her small forelegs, shallow chest, swollen front udder, pointed teats, sick hocks, swollen pasterns and pointed feet. She needs a bull who brings aAa quality 4 (Strong). A bull with aAa quality 4 (Strong) will sire large forelegs, a deep chest, a healthy front udder, plumb teats, healthy hocks, healthy pasterns and short feet.

With a deeper chest, this cow’s daughter will have plenty of room for her heart and lungs to take in air and pump blood to all areas of her body, supporting a healthy immune system and allowing her to grow larger and be more vigorous than her dam – who has a great will to milk but lacks the physical health and vigor to support her natural production potential.

A cow with aAa quality 6

This cow has a flat loin, square thurls, open hocks and small pasterns, so she needs a bull who brings aAa quality 6 (Style). A bull with aAa quality 6 (Style) will sire an arched loin, central thurl placement, neat hocks and large pasterns.

With central thurls and more substance of bone, this cow’s daughter will stand with her rear legs placed squarely under her pelvis and have the substance of bone to walk on concrete for many years without developing lameness and chronic pain like her dam – who has a wide, open pelvis but may be culled prematurely due to mobility problems.

A cow with aAa quality 2

This cow also has a short head, short forelegs, low loin, meaty front udder, low rear udder and cocky tailhead. She needs a bull who brings aAa 2 (Tall). A bull with aAa quality 2 (Tall) will sire a long head, long forelegs, a high loin, an elastic front udder, a high rear udder and neat tailhead.


With a high and elastic udder, this cow’s daughter will be more easily milked than her dam – whose high SCC may be due in part to her low-hanging udder with its abundance of excess udder tissue that can harbor bacteria.

This article originally appeared in print with Breeding for balance with aAa analysis.