Reprinted from Semex's Balance: Winter 2012
By Brad Sayles, Semex Alliance Vice President Global Marketing

Selecting bulls that will help your herd accomplish your production, longevity and profitability goals has become more complicated with the introduction of genomic testing of both males and females. However, deciding how to successfully incorporate genomic tested young sires into your breeding program has a lot to do with first deciding how much risk you are willing to accept.
In order to make the best breeding decisions, it is important to develop a basic understanding of the difference between young sires, genomically tested young sires and progeny proven bulls.

A general rule of thumb when trying to understand these differences is the 30-60-90 reliability rule. This rule is certainly not an exact science. However, it is an easy to understand reference that can be used when thinking about the differences in reliabilities.

• Young bulls with no genomic information and only Parent Average (PA) are known to have a 30-35% reliability
• Genomically tested young bulls are known to have a 60-65% reliability
• Progeny proven bulls with 100 daughters will have a 90% reliability
  

Although some genomically tested bulls can have published reliabilities in the 75% range for production traits (for example in the US system), these high reliability levels have not yet been supported by most validation studies. Therefore, you aresafer to keep using the 60-65% rule above. When thinking about sire selection and utilizing genomics, it’s important to understand that genomic information is a great tool to help you pre-select bulls. And, although the corresponding reliability is quite a bit lower than for a progeny proven bull with 100 daughters, it’s also quite a bit higher than for a young sire with no genomic information and only a parent average.

Having said that, there are ways to utilize genomically tested sires in your breeding program that will have a minimal impact on reliability across the herd. Semex and its Genomax™ lineup have always endorsed using a group or team of genomically tested sires in a herd. This group concept is recommended over the use of just an individual genomic tested sire. For example, using 10 doses from five genomic sires on average will increase that group of bulls’ overall reliability to nearly 90%. Essentially, what you are doing by using a group of bulls is spreading or managing your genetic risk. Consider that if one or two of the five bulls doesn’t meet expectations, the chances are high that the other two or three may exceed your expectations. This will bring the bulls’ progeny proven average very close to their genomic numbers. By contrast, however, if you’re using just one bull, you have to accept a fair bit of risk that the one individual will not achieve the results you expected.

The Semex Genomax™ line-up carries some of the industry’s leading young bulls. At Semex, we strive to include our highest Lifetime Profit Index, Total Performance Index, Net Merit and Type sires in the lineup. At the same time, Semex will always have Genomax™ sires that also carry official Calving Ease and fertility data to give you more confidence when incorporating these bulls into your breeding program.

Semex Genetic Consultants are trained to help you best manage your genetic risk, selecting the very best group of bulls to use in your program. The use of Semex genomic tested Genomax™ sires and SEMEXX™ gender sorted semen gives dairymen more tools, and more power than ever, to incorporate into their genetic strategy and increase profitability.

To read more from the most recent Balance magazine click here.