With August 2017 proofs Holstein Association USA (HA USA) will make updates to TPI, Udder Composite (UDC) and Foot & Leg Composite (FLC). The following information will help you understand these changes and how they may affect sire ranks.
As with any index changes, sires will re-rank. We can attribute most of the re-ranking to the fact that stature is being added to the calculations for UDC and FLC.
Industry standard index changes remind us how important it is to set your own customized genetic plan. While we review the changes being made to Udder Composite and TPI for the upcoming proof round, keep your own genetic plan in mind to ensure it continues to match your farm’s current goals and future plans.
Udder Composite changes
The biggest change that will take place within UDC is that stature is now incorporated with a negative emphasis to promote a more moderate sized frame on Holstein cows of the future. While all individual trait weights within UDC will adjust slightly, stature will now have a relative weight of 17% of UDC. This change comes mostly from the reduced emphasis on udder depth.
A comparison between the previous and new versions of UDC is shown in Table 1 below, with major changes in bold.
|TABLE 1||Previous percent weight within UDC||August 2017 percent weight within UDC||% Change|
|Rear udder height||16%||19%||3%|
|Rear udder width||12%||16%||4%|
|Front teat placement||5%||3%||-2%|
|Rear teat placement (now called Rear teat optimum)||7%||4%||-3%|
|Teat length (now called Teat length optimum)||-||4%||4%|
The other change taking place with udder traits is that both rear teat placement and teat length will now be two-way traits, and be called rear teat optimum and teat length optimum, respectively.
The rear teat length and placement of the Holstein breed has evolved to a shorter and closer average. By adjusting to an intermediate optimum, rather than a close and short ideal, is intended to help get the breed back to a more desirable norm.
The new Foot & Leg Composite
As with UDC, the main difference in the new FLC comes from the addition of stature to the index. Table 2 shows that stature is added mostly from the reduced weight now placed on foot angle and rear leg side view.
|TABLE 2||Previous percent weight within FLC||August 2017 percent weight within FLC||% Change|
|Rear legs rear view||19%||17.5%||-1%|
|Foot and leg score||50%||58%||8%|
|Rear leg side view||8%||-||-8%|
In addition to the UDC and FLC updates, the TPI formula will also be revamped. While the weights within the production, health and conformation categories remain the same, the individual trait weights within the production and health buckets will change.
The biggest change to the new TPI formula is found within the production category as a new protein to fat ratio. You can see all changes in Table 3 below.
|TABLE 3||Previous weight within TPI||August 2017 weight within TPI|
|Somatic Cell Score||-5||-5|
|Daughter Calving Ease||2||2|
|Foot & Leg Composite||6||6|
HA USA reweighted protein, fat and feed efficiency, and therefore adjusted the fat to protein ratio. Starting in August, there will be 6% less emphasis directly on protein, 5% emphasis added to feed efficiency and 1% more emphasis on pounds of fat.
For your reference, feed efficiency is calculated as follows. Please note that Body Weight Composite within this formula is the new calculation to replace Body Size Composite.
Feed Efficiency = (-0.0187 x Milk) + (1.28 x Fat) + (1.95 x Protein) – (12.4 x Body Weight Composite)
In addition to the adjustment on the production bucket, HA USA will now incorporate livability as part of the TPI formula. The 3% weight on livability will come directly from that same reduction in emphasis on productive life.
What do these changes mean?
The new addition of stature to Udder Composite and Foot & Leg Composite, along with the TPI updates, are in place with an overarching goal to aid producers in creating more moderate sized, efficient and profitable cows.
Industry standard indexes can change at any point. These changes reinforce the importance of setting your own customized genetic plan. Work with your trusted Alta advisor to review the weights you place on each individual production, health and conformation trait. We want to help you ensure your plan always aligns with your farms current situation and future goals.