Describe your perfect cow. Maybe words like productive, healthy, fertile or efficient come to mind. Or, maybe your perfect cow can simply be described as profitable. While those are nice descriptors, it’ll take a more specific goal to really make progress toward your perfect herd.

You’ve bought in on the value of genetics. You know that using good bulls makes a clear impact on your bottom line. And, you know the straws of semen in your tank today become your future herd, making an impact for generations to come.

So, how do you pick which straws you put in the tank?

Spoiler alert – there’s not one right answer

If there was a single answer to creating the perfect herd, there would be just one single genetic selection index used by every dairy producer around the world. But, that’s not the case. Instead, a variety of acronyms like NM$, TPI or DWP$ exist. You’ll find many standard index options that come with their own set of pros and cons.

The pros of the standard indexes are that they get you the overall genetic progress you’re after in a more well-balanced way than the age-old single-trait selection plan. They also help you pick which straws to put in your semen tank more effectively than using strict filters on a given trait or traits.

But, the cons of standard genetic indexes are that they make some assumptions. Regardless of which index acronym is first in your vocabulary, it assumes that if you’re farming in Wisconsin, you have the same goals as a dairy producer in Florida or New Mexico.

Plus, many of the dairies I start working with don’t realize which traits and how much emphasis make up their index of choice. Do you know what amount of emphasis is put on each trait in your genetic plan?

Also, the standard indexes don’t guarantee consistency. It takes some attention to distinguish which bulls on any given ranking actually fit best with the goals you want to achieve on your dairy.

Take this trio of industry bulls, for example. Compare your options. Which bull do you think ranks highest on your index of choice? How many index points or dollars do you think separate the best from the worst?

It may come as a surprise that just two Net Merit dollars separate Bull A, Bull B and Bull C. On first glance, it seems almost impossible that bulls this different could have essentially the same index value. But, that’s simply because each bull has different genetic specialties that contribute to their index value total.

If you’re picking from these three bulls, I’m guessing you probably looked first at the traits that matter most to your bottom line. If you’re farming in a fluid market like Florida, you may have immediately discounted Bull B for his low pounds of milk. Whereas, if your milk is made into butter, that same bull may appear as a lucrative option because of his extreme value for pounds of fat.

So, even if you’re confident that your genetic index is aligned with the goals on your dairy, it still takes diligence to know which bulls will best address your needs.

There’s another half to the equation

Let’s say you’re confident in the genetic index you use on your dairy. Maybe it’s a straight-up standard index. Maybe it’s completely customized to your goals. Or, maybe it’s fine-tuned somewhere in between. With your index in place, your herd’s performance will take off with flying colors, right?

Not so fast. Even with the right genetic plan, there’s still another part of this equation:

Phenotype = Genetics + Environment

Or, in simpler terms, a cow’s actual performance is determined by a combination of her genetic makeup and the environment where she lives. But, it’s not an even 50-50 split between genetics and environment, and that split is not the same for every trait.

There’s no question that the actual performance of cows born in 2015 is superior to the performance of cows born in 2010. Between those two groups of cows, some of the difference in their performance is attributed to genetics and some of the difference is attributed to management factors.

As part of the April 2020 base change, the Council on Dairy Cattle Breeding published those figures – you’ll find them in the chart below for five key traits in Holsteins.

From this graph, you’ll notice that cows born in 2015 produced 1,077 pounds more milk than cows born in 2010. And, of that 1,077-pound improvement, more than 90% is attributed to genetics. Genetics also hold the majority share of impact on the 71-pound increase in fat, the 49-pound gain in protein and the 2.66-month improvement in productive life (PL), although the impact is not quite as extreme for these traits.

It’s daughter pregnancy rate (DPR) where environment/management takes over the leading role, leaving the influence of genetics on a cow’s ability to become pregnant at less than a 20%.

Now, this does not mean that you stop selecting for DPR. The genetic contribution of DPR on your herd’s overall reproductive performance is still there, and it’s still impactful. The takeaway from this is simply saying that if you’re looking for a pregnancy rate upgrade, your best bet is to first address management factors for a quick improvement. Then, supplement those management changes by including DPR in your genetic index to create a future herd of more highly fertile cows.

Let your genetic advisers help

With all this talk of standard or customized indexes, trait differences and genetics versus environment, it’s hard to know what’s right and what’s important.

Turn to your genetic advisers. They should be having a conversation with you on a yearly basis, at minimum, about how you choose which straws to put in your semen tank. It’s their job to stay on top of the ever-progressing world of genetics. So, put them to work!

If you choose to use a standard genetic index, your advisers should help you understand the details whenever there’s an index update and how the update affects your selection decisions. And, if you customize your genetic index, it’s your advisers’ role to ensure your plan continues to align with your current plans and future goals. They should review your herd’s actual progress and help you navigate the road ahead to your perfect future herd.

Creating your perfect future herd can be as simple or complicated as you want to make it. So, keep these three key takeaways in mind as you pick which straws to put in your semen tank.

1. There’s not one right answer to the perfect index. Explore your options and have your answer ready to describe your perfect cow. Then, understand your index of choice so you can choose your genetics based on what best aligns with your ideal.

2. There are two parts to the performance equation. Remember that genetics and management both play key roles in your herd’s actual performance, and the impact of that role is different per trait.

3. Lean on your genetic advisers for guidance. It’s their role to help you to understand the details behind your genetics and navigate the path to your best future herd. A strong partnership with your genetic advisers will keep your genetics aligned with your current plans and goals to create your perfect future herd.