DNA Sampling Tips

Mistakes Lead to Slow Responses, Bad Results

Victoria G Myers
By  Victoria G. Myers , Progressive Farmer Senior Editor
Tissue sampling units (TSUs) are the gold standard when it comes to collecting DNA samples on the farm today. (Photo courtesy Neogen)

A lot has changed since DNA testing started in the cattle industry. Hair samples were a beginning. They were fine for what they were. But genetic testing has taken some huge leaps, and Neogen's Stewart Bauck says it's time producers move to Allflex tissue sampling units (TSU).

"These units are the only way to collect high-quality DNA samples today. That is important for a consistently fast turnaround, with the best possible data. TSUs are self-contained, have a bar code, and are highly amenable to automation and robotics. Because that improves turnaround time, it helps lower costs."

Bauck notes Neogen doesn't own shares in Allflex, nor does the company benefit in any way from promoting the use of TSUs.

"Our benefit is that we get a good sample that we can automate," he explains. "We need cattle producers to buy into a good quality system, because it helps the industry as a whole."

Bauck speaks from experience. He says Neogen's lab in Lincoln, Nebraska, still gets hair samples in bags. Often the hair is pulled out of a tail switch, with manure still attached. These samples sometimes have no follicles—important because that's where the DNA is.

Blood cards are often no better. Sometimes wet, they often don't have enough blood to test. Some samples come in contaminated with tattoo ink or chemicals that were applied to animals as they were processed.

Two things happen when a lab gets a bad sample. First, DNA testing is delayed. Second, results can be off. Both defeat the reason for testing in the first place.

Jackie Atkins, director of science and education with the American Simmental Association (ASA), says producers who want the best turnaround times need to send all required information when ordering these tests. Short cuts often lead to confusion and delayed results.

"This means we need to send follow-up emails or make phone calls to get the necessary information here at ASA," she says. "Misidentification is common when this happens because samples go to the lab without proper identification and paperwork and they go into a mystery box, to be deciphered by the laboratory and ASA staff later."

Like Bauck, she says poor sampling techniques are another sure way to have testing fail. That can add weeks to months to a timeline.

Common reasons Atkins and Bauck report for failed DNA testing include:

· Cross-contamination between animals

· Fecal matter and dirt in a sample

· Insect repellent contaminating a sample

· Heat exposure to samples

· Extended storage of samples

Neogen's Bauck says he has one guarantee when it comes to DNA samples. It's a 100% guarantee.

"Send me a bad sample, and I'll send you a bad result. Send me a good sample and I'll send you a good result."


Victoria Myers