news / april
What Genomics Can Do For You
From parentage verification to culling decisions,
genomic testing can serve a variety of purposes on-farm
by Abby Bauer, Hoard’s Dairyman Associate
“SNP chips are information powerhouses,” says
Tami Smith with Neogen Corporation. Smith addressed
the audience at the Dairy Calf and Heifer Association’s
annual conference last week.
A SNP (pronounced snip) is short for single-nucleotide
polymorphism, or a genetic variation in DNA due to
the sequence of nucleotides. Through genomic testing,
we can learn more about these differences and the genetic
make-up of an individual animal.
There are four main ways to use genomics on the farm,
Smith said. One is to confirm parentage. She has seen
farms with 2 to 3 percent of animals misidentified,
all the way up to 40 percent. “Genomics can help
clarify that,” she noted.
Another reason is to make earlier culling decisions.
AgStar estimates show it costs about $2,000 to raise
a dairy replacement. Therefore, a heifer will need
to produce about 32,000 pounds of milk and will likely
be in her second lactation before turning any profit,
“Knowing as much as you can know about animals
when they cost you the most helps you prepare for changes
in the market,” Smith explained. Genomic data
can help identify animals that may not become productive
adults and gives farms an opportunity to cull before
incurring all the rearing costs.
Other on-farm uses of genomic testing include mate
selection and identification of elite cows, Smith noted.
The best time to do genomic testing depends on your
farm’s animal handling abilities, she said. If
you are going to test all animals, testing early is
better because you can make culling decisions sooner.
If you wait a few months, you could do a visual assessment
of size and health and a records appraisal before genomic
testing. Then, you may have a better idea of what animals
you want to test and could be more selective, she said.
If you test on the day of birth, you won’t know
anything about health, performance or environmental
effects on the animal yet.
“How you use your data can change from year
to year,” Smith said, depending on milk price,
feed price and your own farm situation. No matter how
it’s used, she does believe that there is room
for growth in the benefit genomics provides on farms
in the future.
The author is an associate editor and covers animal
health, dairy housing and equipment, and nutrient
management. She grew up on a dairy farm near Plymouth,
Wis., and previously served as a University of Wisconsin
agricultural extension agent. She received a master’s
degree from North Carolina State University and a
bachelor’s from University of Wisconsin-Madison.