Getting cows pregnant is one of the most important functions on a progressive dairy, perhaps the most important one. The degree of profitability is highly correlated with the velocity of pregnancy creation on a given dairy. This is mainly because a pregnancy is the source of a new lactation and a genetically superior heifer replacement.

The A.I. industry offers a variety of selection tools to give the progressive dairy producer an edge in the challenge to get a cow pregnant. What tools are available? What should you know about them? Is it worth anything? This article helps you to answer these questions.

Economic value of a pregnancy
A pregnancy is the source of both a fresh lactation of milk for harvesting and a heifer replacement. So it is not surprising that the economic value of a pregnancy is high. Reproductive specialists and dairy economists have combined to estimate the economic value of a new pregnancy. Researchers have recently estimated the value to range between $200 and $278 per cow.

While highly valuable, there are several factors that affect the likelihood of a cow becoming pregnant on your dairy. Figure 1* illustrates that the chance of getting a cow pregnant is influenced by a range of factors. The most significant is management and environment, but sire fertility and daughter fertility also have an impact as well. And within a given dairy the impact of sire and daughter fertility have a significant impact.

Sire fertility evaluations
So how do you take advantage of sire fertility? Every A.I. company offers some form of “high fertility” product line. The designation of high fertility bulls is based on a standard evaluation method of some sort. There are two main methods of sire fertility evaluation: non-return rates and palpated pregnancy exams. The key difference between the two evaluation systems, along with a description of how a sire’s fertility evaluation goes up or down for each system, is defined in Table 1*.


In both methods of fertility evaluation, it is the relative ability of a sire to get cows pregnant that is measured and compared. Sires that have above-average conception rates (and, conversely, below-average rates of open cows) are considered to offer high fertility. But what measure is more accurate? And what should you consider when choosing from the various marketing lists?

How do you measure fertility?
Accuracy is a huge issue in the A.I. industry. We must strive to provide accurate sire evaluations in order to create value for the progressive dairy producer. Fertility evaluations are no different.

I have never been to a dairy that decides which cows are pregnant by counting the animals that don’t come back for service. As every progressive dairy manager would know, there is simply too much room for error in this indirect method. Instead, you would want to measure a bull’s performance on the basis of how efficient he is in getting cows pregnant, compared to other bulls used. It’s that direct measure of fertility that counts most and is most reliable. And it’s the exact same method you use on your dairy today.

An example from a 3,000-cow dairy from our progeny testing program, AltaAdvantage, in Table 2* shows how the data is measured. This data results from the breeding and routine vet check records. Under the same management and environment conditions found on this dairy, Bulls 2, 5 and 7 are proving to be above average in terms of fertility. Given a 55 percent service rate for the herd, we would expect these “high fertility” bulls to contribute to between 1 percent and 5 percent higher pregnancy rates. This equates to an efficiency gain of about $10 to $50 per cow, resulting from more milk, lower breeding costs and more replacements.

The power of genetics
While important, high fertility should not be the only selection criteria you use in your breeding program. The single focus will leave a huge economic return on the table. The fact is that genetics create the heifer replacements you will milk in the future. So you should pay attention today to invest in the genetics that create the cows you want to milk in the future. In previous articles, we have shown the value that selection for health and production traits have returned to the dairy.

Pregnant profits
The A.I. industry is paying closer attention to select directly for what dairy producers want. We no longer have to look at conformation to guess whether daughters will last; we have Productive Life, which actually measures how long the cow is productive in the herd.

We can also measure the fertility of bulls directly by analyzing their actual fertility in the A.I. pens on progressive, well-managed dairies. This is a backbone method of fertility evaluation in our program, and the same method is used by other companies like Agri-Tech Analytics (ATA).

Being more efficient at creating pregnancies is correlated with the profitability of the dairy. Dairies that create pregnancies quicker also have higher profitability. Sure, sire fertility might only have a 1 percent influence on whether a cow gets pregnant, but progressive dairy managers want to take full advantage of the power of 1 percent. And it’s one of the simplest things you can do to increase efficiency and profitability on your dairy.

There are many tools available to you to help boost fertility on your dairy. We focused on sire fertility evaluations in this article and pointed out the different methods to evaluate sire fertility that you should be aware of. It’s up to you to decide which system you will be confident to use. PD

References omitted but are available upon request at

Figure and Tables omitted but are available upon request to