Use EPDs for selecting best genetics to meet herd goals

DENVER — Using expected progeny differences helps cattlemen make sound selection decisions for their herds.

“We can use EPDs to compare bulls to one another and to see where the bull ranks in the breed,” said Darrh Bullock, professor at the University of Kentucky. “The great thing about EPDs is they include lots of information such as actual measurements of the bull, measurements of relatives of the bull and genomics information.”

Although EPDs are not perfect, they are a tool that provides cattlemen genetic information about bulls, said Bullock at a presentation during the National Cattlemen’s Beef Association 2021 Cattle Industry Convention Winter Reboot event.

For example, a cattleman might compare a bull with a 40-pound EPD for weaning weight to a bull with a 28-pound weaning weight EPD.

“When breeding cows to these two bulls, we’d expect the first bull to have calves on average weigh 12 pounds more than the calves produced by the second bull,” Bullock said.

“The beauty of EPDs is you can also look at maternal traits like milk,” he said. “We can get an estimate on not only how the progeny of the bull will be, but also how his daughters will perform if we put them in the herd.”

Bullock talked about two Angus bulls, one with a 33-pound milk EPD and the second bull with a 25-pound milk EPD.

“That’s not pounds of milk — it’s pounds of weaned calf,” Bullock said.

“If we breed a set of cows with both these bulls and take their daughters and breed them to equal bulls, the daughters from the first bull will raise calves that weigh eight more pounds at weaning than the daughters produced by the second bull,” he said.

“Looking at the percentiles, the 33-pound milk EPD for the first bull puts him in the top 10% for the Angus breed and the bull with 25-pound milk EPD is about breed average for milking ability,” he said.

Each cattleman should think about the economically relevant traits for their herd.

“Traits to one producer may not have any economic relevance to another producer,” Bullock said.

“If a producer is selling calves a weaning, marbling is a trait that doesn’t have economic relevance to that producer,” he said. “Whereas for someone who is selling carcasses, marbling has a high value.”

However, Bullock said, be careful of extremes.

“We need to match the genetics to our management,” Bullock said. “We often get that mental concept that more is better, but we need to think about putting the proper level of genetics into our herds.”

Labor is one consideration for cattlemen.

“How closely you can pay attention to your cattle during calving has a great impact on how much calving ease you need to put into the bull you’re buying,” Bullock said. “As you get more and more calving ease that tends to take away from other production traits, so you need to aim for the appropriate level for your particular situation which is different on every operation.”

Cattlemen should consider multi-trait selection when choosing bulls for their operation.

“We never want to focus on one trait,” Bullock said. “We need to keep in mind all the traits that have economic relevance as we make selection decisions.”

It is important to be aware of genetic correlations.

“As we put more growth into our cattle, if we don’t pay attention to the other traits, we tend to see calving ease start to drop,” Bullock said. “We have to monitor what is happening with other traits or we can get ourselves in trouble in traits we’re not focusing on.”

Genomics can help improve the accuracy of the parentage of bulls.

“Genomics help us to identify true parentage and the reliability of the bulls are greatly enhanced when we get the parentage right,” Bullock said.

“When we get a DNA sample on a bull, it is the same as if we had 24 birth records from that bull,” he said. “We can do this the day he is born and that is a great advantage because it enables us to make selection decisions much faster.”

Although there are many EPDs available to help cattlemen make genetic selection, the most important trait is profit, Bullock said.

“That’s what we need to focus on in selection decisions,” he said. “And profit is not equal to income, you have to remove the cost part.”

EPDs are expressed in units of measurement and indexes are expressed in dollars to give cattlemen an indication of profitability.

“Selection indexes combine multiple EPDs to give us one value to make selections,” Bullock said.

Several different selection indexes are available for each cattle breed.

“Find the selection indexes that are right for your operation and they will help you find the bull that will be the most profitable for your herd,” Bullock said.