Many of us in the dairy industry are thinking about the same thing these days: How do we make the right number of heifers for our operation and create the most value from the rest of our calf crop? Clearly, the market is signaling that we need to stop trying to make as many heifers as we can and change our strategy on types of pregnancies we are creating.
Scott Metzger

Low milk prices have collided with impacts of sexed semen and better calf and heifer development systems to create a perfect storm of excess heifers. While in the past this may have been viewed as an opportunity for some dairymen to create an additional revenue stream, that is not the case today, with prices for open heifers and springers well below what it costs to raise them. At the same time, value of dairy bull calves has fallen to near zero in some places.  

The answer for many dairymen has been to incorporate targeted use of sexed semen, along with beef semen, while minimizing or eliminating use of conventional dairy semen. The strategy is certainly sound and has potential to lower heifer-raising costs while creating additional revenue by capturing a premium for beef-dairy cross calves over dairy bull calves.

There are many factors to consider when moving to a more targeted strategy for your herd. These include current herd size and anticipated growth, cull rate, heifer loss, age at first calving, calving interval and conception rate of different reproductive products. With all these variables, the calculation can become somewhat complex in fine-tuning a strategy to ensure you produce the number of replacements needed for the target herd size. Fortunately, a number of tools have been developed by genetics companies and universities to help producers develop a plan and have confidence they won’t be in an unanticipated situation nine months down the road.

Breeding for genetic gain

One of the most important issues to consider when changing a herd’s breeding strategy is how the future herd replacements will be created. The goal should not only be to make the right number of heifers, but also to ensure these heifers have the highest possible genetic potential.

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Let’s look at an example of one Holstein herd we work with that has focused on using top A.I. bulls for many years. The lifetime net merit (NM$) of their cows and breeding age heifers ranges from 802 to -167, with an average of 383. If they were to randomly pick females from across the herd to breed for replacements and used 900 NM$ bulls, the resulting heifers would have a parent average of 642 NM$. However, if they targeted only the top 50 percent of the females to breed for replacements, the resulting heifers would have a parent average of 703 NM$. Not a bad gain by simply being deliberate about who gets bred for replacements.

Accelerating genetics with embryos

Taking this a step further is the opportunity to incorporate embryos as part of a strategy to significantly increase the genetic level in a herd. In the herd example above, they could choose to make replacements out of the top 25 percent of their females using sexed semen, with the resulting heifers having a parent average of 736 NM$. They could then use another 25 percent of their herd to produce pregnancies from sexed embryos that have a minimum NM$ of 850. This strategy would give their resulting replacements an overall average genetic level of 800 NM$ or greater. This is a huge jump in genetic potential from the original scenario, even in a herd that has used top A.I. bulls for years. Herds with a lower baseline of genetics will see an even greater improvement in genetics using embryos.

This is a simple example that assumes the procurement of commercially priced, high-merit female embryos, but it clearly shows the rate of genetic progress can be dramatically increased by incorporating embryos as part of a herd’s breeding strategy. The correlation of genetic predicted transmitting abilities (PTAs) to actual performance in a herd is a topic that could fill a whole separate article, but suffice it to say that in well-managed herds, the differences in performance are often significantly greater than what the numerical PTAs predict. Thus, the use of embryo technology can dramatically change the productivity of a herd in a single generation.

Along with accelerating the rate of genetic progress, embryos have many other potential applications as well. For example, F1 Holstein-Jersey embryos could be incorporated into a breeding strategy to maximize and maintain heterosis in a herd. For herds that utilize crossbreeding, this could simplify the breeding program and increase herd uniformity as well. As consumer demands change, embryos could also be used to shift an entire herd in one generation to producing A2A2 milk, being polled or even change them from Holsteins to Jerseys.

Other advantages of using embryo transfer

Other possibilities include use of beef embryos in a portion of the herd not being used to create replacements. The resulting pure beef calves will compete quite favorably in the beef feeder market, even as dairymen see more variation in prices they receive for beef-dairy cross calves. Beef embryos could also be sexed male to produce steers to command maximum value in that market. The ability to procure a consistent, year-round stream of feeder calves with known genetics has led to a great deal of interest in this concept from the feedlot sector.

With all these potential applications of embryos, the need to consider the factors we originally discussed becomes even greater. Dairymen should consult with an adviser who has tools to help them develop a plan for incorporating embryos into their herds. As with the use of sexed semen, the goal of this next step in technology should be to ensure you produce the number of replacements you need while maximizing their genetic merit, increasing revenue from other pregnancies and ensuring costs are justified by the additional value created.

As long as we milk cows, we will need to freshen cows. Every pregnancy we create in order to do so has the potential to be a value-added calf if the right strategies are developed for producing that next generation. While it is a challenging time in the dairy industry, it is also an exciting time, as dairymen have more tools than ever to ensure their herds have a genetic advantage in efficiently producing dairy and beef products that consumers demand.  end mark

PHOTO: Photo by Jenna Hurty-Person.

Scott Metzger