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|
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.