aAa is arguably the single most effective breeding tool in the dairy industry today. The results of this “round vs sharp” mating strategy in herds all over the world is evident to any unbiased observer But what is the reason for the extreme imbalance of traits that we see in today’s sire population?
The 3 graphs on the right (see 2017 sire directory)  are taken from information from the Redbook bull database (Dec. 2016). We weighted the aAa traits of bulls according to the order of their first 3 numbers: the first aAa number trait gets 3 points, the 2nd number gets 2 points, and the 3rd number gets one point.
After compiling this information, the strength of each particular trait is emphasized. It is no surprise that the open ‘3’ trait is predominant in the breed at large while the style ‘6’ trait is almost nonexistent. What may come as a surprise however, is the resurgence of strength ‘4’ in the top 100 genomic TPI bulls. This shows the current trend of the Holstein breed; open up most major sire catalogs and you will see mostly 4-3-2 combination bulls. This is an obvious result of many generations of matings devoid of the “balanced mating” approach. Also we believe that the increased emphasis on health traits over the last decade has swung the pendulum dramatically towards strength over dairy character.
Now keep in mind, each aAa trait should be treated with equal importance; there is no one particular trait or number that we hold above another. It is the balance of all 6 numbers that we are looking for.
Takeaway: Single-trait selection will always result in an structural and functional imbalances which in turn is then met with an over-reaction. As the green bar graph (above) exemplifies, Triple-Hil Sires is dedicated to providing you with quality, deep-pedigreed sires to cover all your aAa needs.