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The proof is in your numbers

Let us show you…

We can show you the proof that genetics are one of the cheapest investments you can make to improve the profitability and efficiency of your herd. Proof sheet numbers may seem unclear or unrealistic. So we break them down to see how they translate within your own herd.

When you use a herd management software program, we can create a genetic assessment of your herd to see if genetics really work on your farm.

Do your 2-year-olds give as many pounds of milk as their sires’ proofs predict? Do these cows become pregnant as quickly as their sires’ DPR numbers suggest? And do daughter stillbirth numbers prove to be accurate indicators of DOAs?

When we do a genetic assessment for your herd, it’s important to realize that we only take into account first-lactation animals in order to minimize environmental effects. Phenotype equals genetics plus environment. So when we eliminate – or at least minimize – environmental influences, the actual performance differences we see are due to genetics.

We want to show you how those proof numbers translate to more pounds of milk, more pregnancies and fewer stillborn calves. So here, we take one of our real DairyComp 305 analyses of a real 1,500-cow herd for answers.

The proof in genetics: PTA Milk (PTAM)

We start with PTAM, which tells us how many more pounds of milk a first-lactation animal will produce compared to herdmates on a 305-day ME basis. We set out to find if higher PTAM values on this farm actually convert to more pounds of milk in the tank.

In this example, we sort all first-lactation animals with a known Holstein sire ID, solely on their sires’ PTAM values. We then compare that to their actual 305-day ME milk records.

As Table 1 shows, based on genetics, we expect the top 25 percent of first-lactation heifers to produce 1,541 more pounds of milk on a 305ME basis than their lower PTAM counterparts. In reality, we see a 2,662-pound difference between the top PTAM animals and the bottom in actual daughter performance.

Table 1: How does selection for PTAM affect actual 305ME performance?      
  # of cows Avg. Sire PTAM Avg. 305ME Production
Top 25% high sire PTAM 178 1508 44080
Bottom 25% low sire PTAM 171 -33 41418
Difference   1541 2662

This means that for every pound of milk this herd selects for, they actually get an additional 1.69 pounds of milk. So these first-lactation animals are producing well beyond their genetic potential.

Why do they get more than expected?

When we do most on-farm genetic assessments, we find that the 305ME values closely match the predicted difference based on sire PTAM. However, in this example, the production exceeds what’s expected by more than 1,100 pounds.

We often attribute that bonus milk top-level management, where genetics are allowed to express themselves. This particular herd provides a comfortable and consistent environment for all cows. All of these 2-year-olds are fed the same ration, housed in the same barn and given the same routine. At more than a 40,000-pound average 305ME, this is certainly a well-managed herd, which allows the top genetic animals to exceed their genetic production potential.

Perhaps even more importantly, the identification in this herd is more than 95 percent accurate. Without accurate identification, this analysis simply won’t work. That’s because some cows whose real sire information puts them in the bottom quartile will actually appear in the top quartile and vice-versa.

The proof in genetics: Daughter Pregnancy Rate (DPR)

Our next example from the same 1,500-cow herd shows the benefits of selecting for DPR as part of a customized genetic plan. In the same way as the previous example, we sorted the first-lactation animals, this time based exclusively on their sires’ DPR values, to compare the top versus bottom quartile of 2-year-old cows.

Table 2. How does selection for DPR affect actual pregnancy rates?      
  # of cows Avg. Sire DPR Actual 21-day preg rate
Top 25% high daughter pregnancy rate 176 2.1 25%
Bottom 25% low daughter pregnancy rate 173 -2.2 19%
Difference   4.3 6%

An increase of one point DPR is equivalent to a one-point jump in pregnancy rate, or in other words, four fewer days open. In this herd, we’d predict the top DPR cows to have a pregnancy rate about four points higher than the low DPR group. This means their top DPR cows, on average, become pregnant about 17 days sooner.

What this well-managed herd actually realizes on their first-lactation animals is once again, beyond expectations. Top DPR cows have a six percent higher pregnancy rate than the low DPR group. That six percent difference equates to 24 fewer days open – more than one full heat cycle!

The proof in genetics: Daughter Stillbirths (DSB)

Calves born dead are an economic loss to a dairy. With this in mind, we set out to determine wanted to find proof in DSB figures in this herd. To clarify, a bull’s DSB value tells us how likely his daughters are to give birth to a stillborn calf. A higher DSB means a higher probability for future stillbirths.

Table 3: How does selection for DSB affect actual DOA rates?      
  # of cows Avg. Sire DSB DOA%
High daughter stillbirth 183 10.4 13%
Low daughter stillbirth 146 5.1 3%
Difference   5.3 10%

We know this farm takes extra care in keeping accurate and thorough records on calving ease and DOAs. Because of that, we know their genetic assessment on DSB’s should be accurate.

Here, we sorted all first-lactation animals based on their sires’ DSB values. In this herd, the females with the lower, more favorable DSB values gave birth to 10 percent more live calves than the first-lactation animals out of high DSB sires!

Genetics are real

In well-managed herds with accurate records, we can analyze additional traits. We can break down the differences to show your own herd’s genetic proof in productive life, protein, fat and sire stillbirths.

The proof in genetics is real, and it’s powerful. But farms cannot see this proof if their animals are not identified correctly. True analysis of how genetics work in your herd cannot be done without accurate and precise identification and records.

The traits we’ve analyzed in this example can make a great financial impact for your farm, with very little investment. Each of these examples clearly demonstrates the following:


  1. The proof in genetics is real.
  2. In well-managed farms with herd management software programs, we can show your own herd’s proof of performance from genetics.
  3. When you provide a consistent, comfortable environment, and maintain accurate identification records, you may see animals produce and perform well beyond their genetic expectations.
  4. Work with your Alta advisor to set your own customized genetic plan with emphasis on the traits that match your current plans and future goals. By doing so, you will maximize the proof in genetics through increased herd profit and efficiency.

Source: Alta Genetics

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