There's a trick to breeding stock selection and in the future it will likely involve more emphasis on cardiovascular health to keep up with increasing growth rates and on making cows more efficient, according to speakers at a leading breed association convention held in Colorado Springs in mid-September.

There’s a trick to breeding stock selection and in the future it will likely involve more emphasis on cardiovascular health to keep up with increasing growth rates and on making cows more efficient, according to speakers at a leading breed association convention held in Colorado Springs in mid-September.

The annual meeting of the Red Angus Association of America — now headquartered in Commerce City, Colorado — drew 266 participants from two countries and included a free commercial cattle’s symposium to kick off the event.

Colorado State University veterinarian Tim Holt threw in a few magic tricks to add some fun and humor to his presentation on high altitude disease and why it’s important beyond the intermountain region.

Holt travels the country — and the world — testing cattle for PAP, which stands for pulmonary arterial pressure.

A high reading indicates susceptibility to brisket disease, also called high altitude sickness. The condition happens when vessels in the lungs begin closing off and restricting blood flow, leading to hypertension and causing blood to back up into the heart, which then swells.

Holt’s work shows the problem is beginning to appear more frequently in cattle at lower elevations. The phenomenon is also being observed in other species of livestock, particularly poultry, where the animals have been bred to grow so fast that their hearts and lungs can’t keep up.

“Pigs can withstand huge pressure and not die, but all of sudden that is changing too. Now I’m seeing pigs with hypertension,” he added.

Future studies will examine how PAP scores relate to feed efficiency, growth rate and other performance factors in the feeding phase.

“In our feedlots, cardiac disease is skyrocketing,” Holt said. “I’m going down to Texas Tech to do some more work on this. I think it is something to be aware of. There’s no need to panic about it right now, but if we had started looking at this 30 years ago, we would be ahead of the curve today.”

“In feedlots, we are seeing increasing inflammation of the lungs and that could be tied together with this,” he added. “If the heart is failing, you get pulmonary edema or pneumonia. They go hand-in-hand.”

Some commercial breeders have started offering PAP scores along with other performance data. The test costs about $25 a head and is best done when the animal is 12 to 14 months of age. The trait is highly hereditary, Holt said.

If a herd bull candidate has a high PAP score, the buyer might want to ask whether it is worth bringing him into the gene pool, he said. It’s also a potential consideration when choosing replacement heifers.

In recent years, “stayability” has become a new buzzword in genetic selection. The term refers to the length of time a cow remains a productive part of the herd. Holt said cardiovascular fitness could have some influence on it, joining a constellation of other important traits that are contributing factors.

Oklahoma State University beef production specialist Bob Lalman is an expert on selecting cows that make optimal use of available resources and offer the best returns over time.

Speaking in Colorado Springs, he applauded the industry for progress on post-weaning performance but noted cows have room to improve.

“Over the last 30 years we’ve focused a lot on carcass traits, but in next 20 years I think we’ll see dramatic improvements on the cow side,” he said.

Looking at overall industry trends, some important production traits, like calving ease, have improved dramatically, while others, like fertility, have remained about the same, he said.

Stayability has been a mixed bag.

“Since 1995 this trait has declined or gone sideways for the industry overall, but it looks like the Red Angus breed has improved over that time,” he said.

That is likely due at least in part to moderate cow size. As weaning weights have climbed, so too have mature cow weights. Coupled with increasing milk production, the result is often cows with high feed and maintenance requirements, Lalman observed.

“For every 100 pounds of added cow weight it costs you $54 a year in additional carrying costs for that cow,” he said. “Studies show you get six pounds in additional calf weight per 100 more pounds of cow, and even though some figures put that up closer to 20 pounds, that still won’t pay for the extra cost of that cow.”

“Why not start with a target carcass weight and back up from there?” he added. “Begin with the end in mind, in other words. It’s possible for 1,200-lb cows to give you 1,400-lb fed cattle. As the length of the stocking period changes, you might need a larger cow.”

Milking ability is another piece of the puzzle.

Since 1984, when the average commercial cow was producing 12 pounds of milk a day at peak lactation, that figure has climbed to 31 pounds or more within some herds, he said.

It takes 2 pounds of high quality forage to produce every extra pound of milk, so excess milk production drags down cow condition and fertility when forage resources are limited, he said.

Using a crossbred cow is another trick to improving longevity, fertility and overall performance, one which he believes is currently underutilized by the commercial industry.

“It increases cow productivity by upwards of 30 percent,” he said.

In the way of parting recommendations, he offered a straightforward list: match the cow to the environment, keep only early born and early bred heifers as replacements (and buy bulls out of cows that calved early in the calving period) and look for a breeding stock supplier who manages the cattle the same way you do.

“Ride around with them for a day and find out how they do things. I think that’s important, and we probably haven’t emphasized it enough,” he said.