Genetic selection of beef cattle has evolved considerably in recent times with many more tools available for making breeding decisions, according to University of Nebraska Extension beef genetics specialist Matt Spangler.By Jennifer Bremer from High Plains Mid West Ag Journal.

"Throughout history, we have been able to select our cattle by using many different tools," said Spangler during a meeting at the Nebraska Cattlemen's Classic in Kearney, Neb., recently. "We started with using pedigrees and phenotype, then added performance records, followed by EPDs (expected progeny differences), but now you need to know if you are selling phenotypes or genetics."

He said the primary source used when buying bulls continues to be visual appraisal for both commercial and seedstock beef producers. EPDs are generally the second tool producers will use.

"Producers believe in EPDs and economic indexes, but they still want their animals to be sound, structurally and reproductively," said Spangler.

In a breeding program, he suggested selecting bulls that complement the cows. That means if the cow herd lacks a characteristic that a producer wants to improve on, a bull having that characteristic should be selected.

"Each breed has characteristics that are important for furthering the cattle industry," he said.

Knowing and having an end goal for your calves is important when selecting cattle to remain in your herd. Determining how to get to the end goal is important for producers to determine, also.

"Heterosis--crossbreeding--can improve a lot of herds by increasing calving rate, survival rate, and cow longevity. The longer a cow is in a herd, the more calves she will have, and the more profitable the herd can be," he explained.

Spangler said with heterosis a cow herd can combine traits from both breeds and become more profitable in the long run. "Multiple-trait selection is a good tool to use to get the best you can out of your animals," he said.

DNA testing has also become a more prevalently used tool, as it can be used when an animal is very young to find out important information regarding hide color, horned versus polled genes, and the presence of genetic defects. These are all complex trait tools that can be used to market cattle.

Currently, Spangler expects to see more use of DNA for gathering marker-assisted EPDs. Marker-assisted selection should be seen as a tool to assist with and not as a replacement for traditional selection techniques.

The potential benefits from marker-assisted selection are greatest for traits that have low heritability, are difficult or expensive to measure, or cannot be measured until after the animal has already contributed to the next generation.

With current EPDs, he said it is important to look at accuracy values and know if they are economical. "Accuracy is especially important when selecting reference bulls to use in your herd."

Spangler said it is important to know how to read the EPDs and to realize they can be more highly heritable and accurate than actual weights. "By using weights alone to determine performance, producers can be led down the wrong path," he said. "But, these weights are still important to help determine EPDs; therefore, it is important to use a scale and turn in all the records you collect.

"All of these tools can help breeders and their customers meet their ultimate breeding objective," he concluded.