At the Central Maryland Research and Education Center dairy farm, genomic testing is helping Brian Schnebly determine what heifers to keep.

"Genomics is going to hopefully help us select the ones that will be the least productive of the group, so we can move them on and make room and take better care of the heifers we want to keep," says Schnebly, the center's ag tech supervisor.

The need to do genomic testing comes from the fact that the farm has many more heifers, 110, than milking cows, 70.

"So, we've got more than we need," he says.

Testing the heifers
A total of 70 heifers, in two separate groups, were genomically tested earlier this year.

Schnebly says 40 heifers were initially tested, followed by an additional 30 heifers to get more information on the overall group.

"Plus, we wanted to do more because we figured we needed to cull somewhere between 20 and 30 before winter hits, and really only testing 40, we wanted to have a larger group to pull those 20 or so from," he says.

Tissue samples were taken from each heifer's ear and sent to an outside lab where DNA was extracted from the tissue. From there, technicians searched for individual markers in the DNA called single nucleotide polymorphisms (SNPs) where the DNA sequence can differ between animals. These SNPs are useful as they correspond to genes that determine a specific trait, such as color of the animal, or how much milk the animal will produce. Computer chips can identify more than 50,000 SNPs in a single animal,

The farm's managers worked with Victoria Baker of Zoetis with testing done using the company's Clarifide program. Within a few weeks they got results from the company.

The results
During a recent tour of the farm in Ellicott City, Md., Schnebly talked about the things he's learned about his herd using genomics.

He holds two pages of Predicted Transmitting Ability (PTA) numbers generated from the tests. PTAs are the predicted difference of a parent animal's offspring from average due to the genes transmitted from that parent.

So, what's been learned since testing was done earlier this year?

"There's a lot of variation," he says. "We got a lot of improvements to be made."

With genomics, farmers get a window into their animals' genetic potential within a span of a few weeks, vs. traditional progeny testing that can take years to complete.

While farmers breed animals for different characteristics, Schnebly says he breeds for production.

"We want cows that are going to be profitable, so this dairy wellness (trait) is kind of ideal because it incorporates several of the things we're looking for," he says, including quality of the udders, feet and legs.

But the tests also surprised him. Some of the heifers he thought were good replacements based on looks turned out to be ones that he likely will not keep.

"Just because they look good doesn't mean they're going to be profitable down the road," he says. "That can be eye-opening because you develop your favorites on how they look or based on their temperament, or even color. The red ones are favorites down here, but they might not always be the ones that will make us money down the road."

Baker says farmers should consider what genomics can do for their herd, but always start with setting a strategy.

"And that strategy can be different for every dairy," she says. "It might as simple to find the bottom animals and cull them or finding the top animals and do some embryo transfer or IVF (in vitro fertilization) and multiply the best animals to breed a better cow."

Changes in management
Schnebly says he's already seeing results from using higher artificial insemination genomic pools — all breeding is done via AI — to improve profitability.

"There were a few daughters (from the second group) of bulls from when I started doing genomic selection. When Vicky pulled up the numbers I could see a difference in the overall average of the whole group," he says. "The second group was higher than the first group. I've already started seeing progress and there was only a six-month gap there. We're moving in the right direction."

Baker says she focuses on reproductive and health traits on her own 80-head dairy farm in Scottsdale, Pa., as she tries to build that "invisible cow" of the future with great looks and good production.

When it comes to genomics, Baker says Holstein numbers are more reliable than other breeds since there are more animals in the overall pool to test. The reliability of PTA scores can also vary by trait, with production traits such as milkfat and protein having higher reliability scores in Holsteins than Jerseys or other colored breeds.

The company's Clarifide test, she says, costs $44 per head. It might be a little pricey for some farmers, especially considering the depressed milk prices, but Baker says it's worth paying more now to bank on a brighter future tomorrow.

"Genomics adds value no matter what breed you're using because it still increases the reliability," she says. "If I was going to the casino, I'd want to increase my odds."