The proof is in the numbers

Genetics Matter…

And there’s proof in genetics as one of the cheapest investments you can make to improve the profitability and efficiency of your herd. While the numbers on a proof sheet may sometimes seem unrealistic or unclear, once you break it down to see how they translate on a herd-level basis, it becomes very real.

Using herd management software programs, we can create a genetic assessment of any given herd to see if their animals truly live up to their genetic potential.

Are 2-year-olds giving 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 look into these analyses, it’s important to note that we take into account just first-lactation animals in order to minimize environmental effects. Phenotype equals genetics plus environment, so when environmental influences are completely minimized, more of the actual performance is attributed to genetics.

We can compare cows with additional lactation’s in the same way, but we have to realize the results will be biased. Non-performing cows, regardless of sire, will likely have been culled before reaching later lactation’s. The most accurate and precise genetic comparisons with the fewest outside factors come from comparing first-lactation animals.

So for a better grasp at how the numbers on the proof sheet translate to more pounds of milk, more pregnancies and fewer stillborn calves, we look to a Dairy Comp 305 analysis of a real 1,500-cow herd for answers.

The proof in genetics: PTA Milk (PTAM)

We start with PTAM, which indicates how many more pounds of milk a first-lactation animal will produce compared to herdmates on a 305-day ME basis. This farm’s data gives us the proof in genetics, showing that selection for higher PTAM sires truly converts to more pounds of milk in the tank and more dollars in the bank.

In this first example, we compare actual 305-day ME milk records against sire PTAM values to see if daughters in this herd are producing to their genetic potential. To do this, we sort all first-lactation animals with a known Holstein sire ID, solely on their sires’ PTAM values.

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: Effect of selection for PTA Milk on actual 305-day ME production
# of cowsAvg. Sire PTAMAvg. 305ME Production
Top 25% high sire PTAM178150844080
Bottom 25% low sire PTAM171-3341418
Difference15412662
This means that for every pound of milk this herd selects for, they realize 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?

In most on-farm genetic assessments, the 305ME values closely match the predicted difference based on sire PTAM. In this example, the production exceeds what’s expected by more than 1,100 pounds. Many attribute this to 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 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 because some cows whose real sire information would put them in the bottom quartile will actually appear in the top quartile and vice-versa.

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Polled genetics – Examine the pros and cons

The polled gene in dairy cattle is dominant over the horned gene

Polled dairy cattle trace back at least as far as pedigree records have been kept. The polled gene in dairy cattle is dominant over the horned gene. Yet horned cattle are still much more prevalent in the global dairy population because few producers ever chose to select for polled cattle as part of their breeding program. This is because the real, economic paybacks of selecting for production, health and conformation traits has traditionally trumped the desire for polled genetics.

Genomic selection has allowed polled enthusiasts to focus on high ranking polled animals to propagate the polled population. However, producers stressing genetic improvement in other traits are also advancing their genetics at an equally rapid rate.

You can add polled as a criteria to your genetic plan, but must keep in mind the financial repercussions of that decision in terms of the pounds of milk and components you’ll give up, and the health and fertility you may need to sacrifice, just to avoid dehorning.

The more recent public awareness about dehorning cattle has made it another hot button topic in the industry. The naturally hornless cattle have gained popularity in recent years because of consumer opinion on the dehorning process, and the side effects they feel result from it. This perception has driven producers to create more naturally polled animals than ever in the past.

The pros of polled genetics

Despite the genetic and performance sacrifices made by selecting for polled animals, many producers do see the opportunity to incorporate polled genetics into their breeding program.

  • Avoid dehorning

You can save dollars, time, and labor, and also minimize stress on your calves by foregoing the need for dehorning. The average dehorning cost varies from one farm to the next based on the chosen method of dehorning, and there is a chance of causing additional stress on the calves during a crucial growth time.

However, it’s important to remember that modern dehorning methods done properly, and at an early age, will nearly eliminate stress on the calves, and will minimize your time and costs.

  • Cater to consumer perceptions

It’s a fact that consumer perception directs many aspects of the dairy industry’s reality. Animal rights activists have criticized dehorning for years, but it hasn’t been until recently that the general public has joined the activists’ view on dehorning as a detrimental process. With increased awareness about this common farm chore also comes increased consumer demands on how they feel farmers should handle it on their dairies.

We clearly don’t want animals with horns running around dairies, so the question is whether to dehorn calves or breed for polled genetics. Unless consumers are willing to pay a premium for milk from naturally hornless cattle, you will likely be leaving dollars on the table by selecting exclusively for homozygous polled sires if you want to ensure no animals are born with horns.

  • The polled gene is dominant

The basics of genetics tell us that since the polled gene is dominant over the horned gene, animals with one copy of the polled gene and one copy of the horned gene will not have horns, and a naturally hornless animal can be created in one generation. It also means it is easier to make more polled animals faster than if the polled gene was recessive.

An animal can have one of three combinations for the polled/horned gene:

PP = homozygous polled means this animal has no horns, an all offspring from the animal will be born without horns
Pp = heterozygous polled means this animal does not have horns, but offspring may or may not have horns depending on their mate
pp = born with horns

If you’re starting with only horned animals in your herd, the figures below demonstrate your results mating cows to a polled sire. The table on the left shows that a homozygous polled bull bred to a horned cow will result in 100% hornless offspring. The table on the right illustrates that a heterozygous polled sire bred to a horned cow will result in only 50% polled offspring.

Punnet square to demonstrate the resulting offspring when a homozygous polled sire is mated to a horned dam
A homozygous polled sire mated to a horned dam results in a 100% chance of polled offspring.
Punnet square to demonstrate the possible resulting offspring when mating a heterozygous polled sire with a horned dam
A heterozygous polled sire mated to a horned dam results in a 50% chance of heterozygous polled offspring and a 50% chance of horned offspring.

The downside to polled genetics

While eliminating the need for dehorning may seem like the right choice for your dairy, the genetic sacrifices you will make in order to get to that point cannot be overlooked. Whenever you add extra selection criteria to your genetic plan, you will sacrifice in other areas. Here are just a few reasons to think twice about selecting exclusively for polled genetics in your herd.

  • The continuous need for polled sires
    Like mentioned above, the polled gene is dominant, so you can create a polled offspring in just one generation. What many producers tend to forget is that, at this point, maintaining a population of polled cattle in your herd is much more difficult.

As the images above show, using a heterozygous polled bull will not yield 100% polled offspring. To get to the point of a completely polled herd, and to maintain it once you’re there, you continually need to use only homozygous polled sires. This may not seem difficult, but it leads to the next shortcoming of using exclusively polled sires.

  • Limited availability and variation on polled sires
    Since the prevalence of polled animals within the various dairy breeds is still low, it will still take many generations to genetically eradicate horned animals from your herd if you want to maintain reasonable inbreeding levels.

Even though the number of polled bulls in active AI has increased substantially over recent years, the total number of sires providing that polled gene is still limited. AI companies will only bring in bulls at genetic levels high enough to help you make progress in your herd. And since selection for polled animals has only recently gained popularity, many of the polled bulls are closely related – either from a small group of elite polled cow families or with sires in common.

Yet even with selection standards in place for the elite polled animals of the dairy population, the genetic levels don’t yet match up.

  • Genetic sacrifice and compromised future performance
    Most importantly, at this point in time, polled bulls don’t yet live up to the genetic levels of their horned counterparts. With polled as a strict selection criteria, you will miss out on from the best sires, regardless if you select from the genomic or daughter-proven lists. When you figure the amount of production, health and conformation that could be lost by limiting your options to only polled sires, dehorning calves becomes even less of an issue.

Review your pros and cons for polled genetics

As you set your genetic plan keep in mind the pros and cons of selecting exclusively for polled genetics. At this point, the overall genetic and performance levels of horned animals still outpace those of polled cattle. Modern dehorning methods minimize stress on calves, so when performed correctly and at the proper time, it should be almost a non-issue.

On the flip side, you could make a case for exclusively polled sire selection if your milk plant is willing to pay more for milk from polled cattle, or if consumer perception drives your decisions.

Regardless of your selection decision, make sure it aligns with the customized genetic plan you put in place so the genetic progress you make on your farm is in the direction of your goals.

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Inbreeding: manage it to maximize profit

Inbreeding has become a hot topic in recent years…

Producer concern is on the rise over whether genomics is creating too much inbreeding in the dairy cattle population. The worry is that there will soon be limited options to which a herd can be bred to avoid negative effects of inbreeding. Mating an animal to her father or brother is certainly not desirable, but we need to ask what the real goal is in terms of inbreeding. Should we aim for zero percent inbreeding or rather manage it to maximize profit?

The linear effect of inbreeding depression

As animals become more related to each other, inbreeding depression or sub-par productive performance can occur. Inbreeding depression is not ideal, but it should still be weighed against the potential added value from genetic gain.

A common misconception is there is a magic level of inbreeding that we should never go beyond for any given mating. In reality, numerous studies over time have shown the effects of inbreeding depression to be linear.

For every 1% increase in inbreeding for a mating, you will realize $22-24 less profit over the life of the resulting offspring. The same cost, or loss, is predicted when going from 9% to 10% inbreeding as is expected between 1% and 2%.

Genetic progress

It’s well-documented that inbreeding has been on the rise since the mainstream adoption of AI. Despite this increase, dairy cattle have made significant strides in production traits like milk, fat, and protein. It’s safe to say that producers would not trade today’s high producing cows for the less inbred, but also lower producing, cows of the 1960’s.

Inbreeding and milk production graph

Real-world examples

Let’s look into the records of a random cross-section of 10 upper Midwest dairies averaging 1,500 cows, who implement a mating program on their farm. This analysis shows how cows with superior genetics are more productive than cows with inferior genetics, despite the more highly productive group also being more inbred.

In this analysis, cows born between 2005 and 2010, with at least one lactation on record were included. Each individual herd was first analyzed separately, and cows were split into quartiles based on their individual level of inbreeding.

Total # of cows% InbredNM$Milk Deviation1st Lact 305-Day MilkPTA DPRAvg. 1st Lact Preg RatePTA PL
25% MOST inbred from each herd38107.0158649282580.422.51.4
25% LEAST inbred from each herd37844.5121296278750.422.60.9

Here, you can see the difference in genetics, 1st lactation milk production, and NM$ between the top 25% most inbred from each herd and top 25% least inbred animals from each herd. The most highly inbred quartile of cows was also the most genetically superior group of cows in each of these ten herds.

Despite the elevated inbreeding in the most highly inbred quartile of each herd, the genetics more than make up for that when their actual performance is measured. The NM$ levels, pounds of milk and milk deviations were all favorable for the more highly inbred, but also more genetically superior group.

This is not to say that selecting a mating resulting in a 25% inbreeding level is the best option, but rather that when managed properly as part of a program, excellent genetics can more than make up for predicted inbreeding depression.

What many producers also don’t realize is that current proof values of a bull already account for the level of predicted future inbreeding. Adjustments are made in favor of a bull that is considered an outcross sire, and a bull that is more closely related to the average population will see a negative impact on his PTAs because of these adjustments.

Manage inbreeding to maximize profit

To manage inbreeding, we look to an example to see how managing, rather than avoiding inbreeding is the best route.

The example below shows three options to use for a mating in your herd. Sire 1 and sire 2 both offer high Net Merit $ levels. However, their 8% and 6.5% inbreeding levels would be above the suggested 6.25% industry standard, which would eliminate them as potential mating sires in many breeding programs. Sire 3 would be a logical outcross mating in this example, resulting in a mere 1% inbreeding.

Sire OptionSire NM$Inbreeding % with cow being bredEconomic loss due to inbreedingAdjusted NM$ for level of inbreeding
18548.0184693
28456.5150695
36051.023582
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The genetic guide to healthier cows

Industry buzz has been booming about new genetic programs that promise to create healthier cows.

That means it’s the perfect time to revisit the impact that selection for Productive Life within your genetic plan can have on the overall health and longevity of your cows.

 

The Productive Life (PL) number that appears for any given sire on your proof sheet is defined as the number of months longer (or shorter) that his daughters will be productive in your herd as compared to herdmates. If a bull is 7.0 for PL, his daughters within a given herd are predicted to live seven months longer than the average cow in that herd. If a bull is -2.0 for PL, his daughters are predicted to live about two months less than the average cow in that given herd.

PL is often associated with old cows. However, if you think about which cows live longest in your herd, it would be those that have no troubles calving, fewer incidences of mastitis, no respiratory issues, fewer hoof problems, and so on.

Four-event cows

In reality, genetic selection for PL doesn’t just mean more old cows; it predicts which cows are toughest, healthiest and easiest to manage. We call those the four-event cows. If you look at a cow card on your herd management software program, a four-event cow has only four events listed throughout her lactation: 1-fresh; 2-bred; 3-confirmed pregnant; and 4-dry.

If those four events are the only major things a cow experiences throughout her lactation, chances are she’s trouble-free, making you money, and will stick around for several lactations.

Any time an event takes place, such as milk fever, a displaced abomasum, retained placenta, mastitis, pneumonia, or any other disruption to the normal progression of a cow’s lactation, milk is lost. In addition to lost milk production, vet and treatment costs add to the dollars lost.

The proof is in the numbers

Selection for Productive Life propels you toward the goal of a herd full of four-event cows. Since the actual measure of PL is not calculated until after a cow leaves the herd, we can use other ways to see if higher PL bulls actually create healthier and more trouble-free cows.

Productive Life Table Chart

Table 1 breaks down the events within a real 2,400-cow Holstein herd on all first lactation animals with known sire ID’s. Based only on the animal’s parent average or Productive Life, this shows the extreme difference in health events between cows with a high PL pedigree versus those with a low PL pedigree

These are real numbers, recorded on this farm’s herd management software program. Keep in mind, management is consistent throughout the herd, and no preferential treatment is provided for any given cows.

As the table clearly illustrates, far fewer of the high PL cows had issues after calving and throughout their lactation. Fewer cows from high PL group were coded as ‘do not breeds’ (DNB) and therefore, fewer of the high PL cows died or were sold. This means more cows from within that high PL group claimed the title of trouble-free, four-event cows.

On your dairy, how much does a displaced abomasum decrease a cow’s profitability over her lactation? How much of your milk check is sacrificed with every case of mastitis? How many dollars are lost for every lame cow or case of pneumonia? If you put a dollar value to the lost production and treatment cost associated with each extra health event experienced by the group of low PL cows it adds up significantly.

Want healthier cows? Let Productive Life get you there

While environment, cow comfort and overall management practices all play an integral role in the health of any given herd, genetic selection can also aid your quest for a herd of healthy, trouble-free cows. To do that, keep these points in mind.

  1. Genetic selection for PL will help you create longer living cows.
  2. Despite new genetic programs promising added immunity or greater health during a cow’s transition period, PL remains the standard for breeding tougher, healthier cows with fewer issues throughout their lactations.
  3. Include selection for PL as part of your customized genetic plan in order to build your herd of the profitable, four-event cows.
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A Q&A on DWP$ and WT$ – Dairy Wellness Profit $ / Wellness Trait $

Dairy Wellness Profit $ and Wellness Trait $ indexes

The Dairy Wellness Profit $ and Wellness Trait $ indexes may have you wondering whether you should adjust your genetic plan to include this new information. Here we have answers to 14 questions to help you decide what’s best for your dairy to make the maximum genetic progress in the direction of your goals!

What is Dairy Wellness Profit $ (DWP$) and Wellness Trait $ (WT$?)

WT$ is a combination of the Wellness Traits (Ketosis, Displaced Abomasum, Retained Placenta, Metritis, Mastitis and Lameness). This means it is an index analogous to a 0-100-0 index, with 100% weight on health traits. However, those weights are divided between the various Wellness traits that Zoetis calculates.

Do each of the Wellness Traits get their own evaluation?

Yes. They are then combined into a Wellness Trait $ index to combine the expected impact.

How is Dairy Wellness Profit $ (DWP$) compiled?

Dairy Wellness Profit $ (DWP$) is a genetic selection index that equates to a genetic plan of 34% Production – 56% Health – 10% conformation. This differs from TPI (46-28-26) and the overall NM$ index (43-41-16).

The breakdown of the weight on health is different as well. DWP$ puts 30% of the weight on WT$, leaving 26% for the CDCB evaluated health traits of PL, DPR, SCS, DSB, DCE, CCR, HCR.

Are the Wellness traits developed by Zoetis?

The WT$ calculation is not a new concept, as it was first published in 2004, however this is the first routine evaluation and first genomic prediction for those traits.

Did Alta test all bulls for DWP$ and WT$?

No, but we tested the sires that we predicted would do well on the respective indexes based on their health trait values and how they rank on a 34% Production-56% Health-10% Conformation index. We are listing the top ten DWP$ sires and top five WT$ bulls in each of three categories: G-Stars, FutureStars and daughter-proven sires.

What is Alta’s testing plan going forward?

This will be dependent on the feedback from the customers and the demand for this information. In the short-term we will continue to test those sires that rank well on a traditional 34-56-10 index.

How can we predict which sires will do well on these indexes?

Because the correlation between DWP$ and a traditional 34-56-10 index is very high, we can predict quite well which sires will rank well on the DWP$ index.

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