A New Tool for Your AI Program:
USDA Will Release Sire Conception Rate Evaluation in August 2008

Dr. Bob Welper - Global Director - Product Development

Einko Topper - Global Director - Production & Quality Control

How much genetic improvement do you make in the absence of a pregnancy? None. How much milk will be created without a pregnancy? None. How much money will a dairy make without milk? None.

So, getting cows pregnant is obviously one of the most important functions on a progressive dairy. Perhaps THE most important one. A pregnancy is the source of a new lactation and a genetically superior heifer replacement. The management challenge, therefore, is how to maximize the number of pregnancies created on a weekly or monthly basis.

Progressive dairy producers will get a new tool to rise up to that challenge this summer, when the USDA releases a new evaluation called Sire Conception Rate (SCR) in August 2008. It promises to be a more accurate evaluation of male fertility, and it will provide valuable new information that you can use to improve the economic returns from your selection strategy.

The Goal is Pregnant Cows
The breeding program on a progressive dairy is first and foremost focused on creating pregnant cows. However, there are several factors that affect the likelihood of a cow becoming pregnant.

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. This relates to such things as cow comfort, nutrition, transition cow programs, and people on the dairy. In comparison, genetics account for 4% of the variation in fertility. The fertility of the female accounts for 3%, while the service sire fertility is 1%.

Drilling down to the farm level on a progressive, large herd shows a more detailed and wide range of performance on a sire by sire basis.

Sire Fertility Varies on the Dairy
If you have ever generated a bredsum (DairyCOMP) by sire, you will have noticed that sire fertility can vary significantly. Figure 2 is from an actual dairy that shows an average conception rate of 35%. The range around that average is from 30% to 44% - or 14% points!

It is important to note that this is data from a single dairy where the management and environment conditions are the same for all the breedings. So the influence is a constant, and relative differences are owing to sire fertility (and assuming the random breeding of cows with high versus low fertility themselves, which is not an unrealistic assumption).

Sire Conception Rate (SCR)
The USDA’s August release of Sire Conception Rate (SCR) is a researched effort to report the fertility performance on individual bulls marketed by AI companies. It will replace the Estimated Relative Conception Rate (ERCR) model for evaluation. Table 1 compares SCR and ERCR to show the main differences that matter to dairy producers:

With the SCR comes a more accurate approach to sire fertility evaluations – over 20% more accurate than ERCR! Finally, the evaluation will be based on KNOWN PREGNANCY STATUS. And the evaluation will use 100% of the data available and eligible, including data from cows undergoing multiple breedings.

Alta shows leadership through ConceptPlus program
In short, the AI industry is catching up to how progressive dairy producers actually determine sire fertility on their own farms – actual pregnancy exams! For Alta, this is nothing new, as we have been evaluating sire fertility in the ConceptPlus program exclusively on the basis of vet-check exams. This method of evaluation started with the inception of the Alta Advantage® program in 2001, the industry now follows.

How can SRC be used?
Like all sire proof information, SCR is another piece of information that can be taken into account when setting up your AI program. Clearly, you can make SCR part of your sire selection strategy.

Relatively high fertility sires can give your reproduction program an added boost that is simple to implement. To show how this works, let’s assume that the industry average SCR is 35%, and that is the same average for your dairy.

Table 2 below shows the predicted effect of using two different bulls, one with SCR +3.0 and SCR -3.0. The impact is 3% points higher pregnancy rate, when comparing high SCR vs. low SCR. This equates to 3 more pregnancies per 100 eligible cows for every 21 day cycle.

SCR: Show me the Money!
High fertility represents “real” economic value. As we said earlier, 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 fertility is high.
Alta estimates the economic value of 1% higher conception rate to be $3.33 per dose of semen. So +3% SCR means an extra value per straw of $10 !!
These values follow from an estimated economic return to a typical dairy of $20/cow/year for a 1% improvement in Pregnancy Rate, and assuming a 50% Service Rate, a $10/cow/yr return for a 1% improvement in Conception Rate.

The economic value of better fertility is tremendous, and sometimes very simple to achieve. However, is it the only thing to focus on?

Pregnancies = The Power of Genetics
While important, high fertility should not be the only selection criteria you use in your breeding program. That singular focus will leave a huge economic return on the table and untouched. The fact is that genetics create the heifer replacements that 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. Combining the production, health and type criteria important to you with higher fertility is a winning and profitable solution.

A Big Step Forward
With SCR, the AI industry is paying attention to more accurate evaluations of sire fertility that will benefit producers. Just as we no longer have to look at conformation to guess whether daughters will last (see Productive Life), we can now measure the fertility of bulls directly by analyzing their actual fertility in the AI pens on progressive, well managed dairies. This is a backbone method of fertility evaluation in the ConceptPlus program that originates in the Alta Advantage® young sire program, and now the industry is descending on the same approach.

The Take Aways:

• USDA will release the Sire Conception Rate evaluation in August 2008
• SCR is 20% more accurate than existing evaluation (ERCR) as it is based on KNOWN PREGNANCY STATUS, all breedings, adjusts for inbreeding, and includes sire-age and stud*year effect.
• SCR should be part of your sire selection strategy
• High sire fertility delivers significant improvement in pregnancy rates and profitability
• Sire fertility AND genetic merit should be combined in your AI program strategy
• With introduction of SCR, the industry follows Alta Genetics ConceptPlus approach, where the quality of the data in ConceptPlus is still superior with Advantage being the source.

Posted Jul 31st

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