Brave New World

Accurately predicting the carcass potential of identified genetics typically has been as fast and easy as building a bunkhouse out of toothpicks. By the time a sire's carcass merit starts coming into focus - after some of his progeny are fed and harvested - users often discover they either have invested too much opportunity in a carcass dud or have sacrificed too much potential by not using a carcass dynamo hard enough.

Moreover, even when genetic carcass merit is established with Expected Progeny Differences (EPDs) built on progeny carcass information, the proof usually comes from limited data.

As an example, the American Angus Association (AAA) has the most extensive beef carcass data bank in the world. But John Crouch, AAA director of performance programs, explains: "In the Angus breed, we have growth data on more than 120,000 sires. Of that group about 18,000 sires are currently in use (at least one calf registered during the past two years). Of those 18,000, only 1,379 have carcass data on file. Of those, only 227 have more than 35 carcass records on file.

"So, in essence you have 227 sires semi-proven for carcass merit to choose from. But ultrasound technology offers the industry a non-destructive way to characterize the entirepopulation for carcass merit," Crouch says.

Picture The Future, Fast Crouch is referring to Centralized Ultrasound Processing (CUP). Pioneered by AAA and Iowa State University (ISU), the concept uses ultrasound measures of ribeye, outside fat and intramuscular (IM) fat in yearling bulls and females to build EPDs.

In a nutshell, CUP-certified technicians collect the ultrasound images using a common protocol and software, and then they send them to ISU where the images are interpreted via a standardized analysis. The idea is to minimize error and variation associated with data collection and interpretation so it can be used to calculate EPDs.

"Speed is the advantage. You can shorten the generation interval," says Gene Rouse, an ISU animal science professor who has spent the past 13 years sorting out ultrasound possibilities for beef cattle with fellow researcher Doyle Wilson. Where progeny testing requires three years to get a first snapshot of genetic carcass potential, Rouse says CUP data funneled into carcass EPDs can provide the same picture two years sooner.

"It's the most exciting thing I've worked with during my tenure with the Angus breed," says Crouch, who has been with AAA through the industry's performance evolution from ratios and estimated breeding values to most probable producing abilities and EPDs. Last fall, AAA released its first carcass EPDs calculated from CUP data. The organization offers these as well as those generated from carcass progeny data.

"In the last year, we have accumulated almost as much carcass information using ultrasound as we have in the last 25 years," says Crouch. He says progeny ultrasound data representing 2,153 sires were submitted in 1999, while progeny test data on 2,378 sires were submitted between 1974 and last year. And, that's just Angus. Ten beef breeds currently are involved with CUP.

According to Rouse, ISU's laboratory processed ultrasound images for approximately 50,000 yearling bulls and females last year, compared to about 10,000 in 1998. This year, he, Wilson and CUP manager Craig Hays project 100,000 head will go through the system.

"Demand has certainly increased and so has the number of technicians," says Lorna Pelton of Pride Livestock in College Station, TX, a CUP-certified technician who scanned almost 12,000 head herself last year. Producers used to only worry about scanning their bulls, but Pelton says about 40% of her work last year was on heifers. While seedstock producers used to be her only clients, she says about 10% of her customer base is now commercial producers.

Ultimate Accuracy Is The Key For all of the excitement, though, even some of the breeders collecting ultrasound data tend to be cautious or downright skeptical. They wonder whether or not EPDs built with ultrasound data are telling producers the same thing as EPDs built with actual progeny carcass data.

First, progeny carcass evaluations offer up marbling measured directly on the rail. With ultrasound, carcass quality is measured via a marbling estimate based on the IM fat measured with ultrasound.

Henry Bergfeld, manager of Summitcrest Performance Angus at Summitville, OH, sees the potential for ultrasound. But he wonders how an ultrasound EPD can be as accurate as a bull proven with lots of progeny data.

"I suggest very strongly that the actual carcass EPDs are extremely accurate. At this point in time, if you use bulls with high accuracy (0.8 and higher), you can take them to the bank," explains Bergfeld. "I have bulls with carcass EPD accuracies higher than the correlation between progeny data EPDs and ultrasound EPDs."

In round numbers, Rouse explains the correlation between the ultrasound and progeny data EPDs at AAA run more than 0.70 for fat, IM fat and ribeye. In essence, he says that means ultrasound is measuring the same traits as those with progeny data.

Moreover, Rouse compared the progeny data and ultrasound EPDs of the top 12 Angus bulls. Both evaluations ranked them the same way and the correlation between them was 0.84.

However, C.K. Allen of Woodland Farms in Savannah, MO, compared all of the bulls in the Angus sire summary that were at least 0.85 for accuracy on marbling in the progeny evaluation with the same bulls that were at least 0.70 for accuracy on IM fat in the ultrasound evaluation. He found some startling differences.

About 68% of bulls were on the same side of breed average in both evaluations. But, a substantial number of them were different in their rankings. And, 32% ended up on opposite sides of breed average between the two evaluations.

For instance, Allen studied a couple bulls he'd used in the past, one that ranked in the upper 5% of the breed for marbling with an accuracy of 0.98 and one that ranked in the bottom 5% of the breed for marbling with a 0.93 accuracy.

The preliminary ultrasound evaluation placed both bulls near breed average for IM fat with accuracies of 0.91 and 0.85, respectively.

"When you end up with antagonistic results between bulls, it calls the whole thing into question," says Allen. "My big concern is which evaluation is right and how do we know over time?"

Overall, with few exceptions, Crouch explains EPDs built with CUP data are ranking Angus bulls the same as with progeny data.

"There is no question ultrasound is as accurate as progeny test data," says Crouch. Plus, he explains progeny test EPDs can't account for the dam side of a calf's genetics, but their ultrasound evaluation model can. "With contemporary groups and animal modeling that is able to account for the dam side of the pedigree, it will make ultrasound even more accurate," says Crouch.

As well, Crouch emphasizes the preliminary ultrasound report issued by AAA last fall was just that, a preliminary snapshot that didn't include dams in the statistical modeling. Plans call for two more ultrasound evaluations this year that will include dam affect and give the association a chance to evaluate its procedure and results.

Still, for now, folks like Bergfeld and Allen, who each collect ultrasound data along with progeny carcass data, plan to use the progeny data for selection.

"We have commercial producers looking at our carcass EPDs, and they can see the differences in their calves. We can't turn them loose with the ultrasound data until we know they will see the same differences," Allen says.

Others, like Doug Hoff at Scotch Cap Angus Ranch in Bison, SD, founder of Angus America, believe, "Ultimately, I think the ultrasound EPDs will be a better tool than the progeny test EPDs because those have been established with so few cattle. I think it's like any tool. It's going to be good, but it's going to take a little time to work out the bugs."

In the meantime, Hoff says, "I definitely would caution people to look at the pedigree, the actual carcass data EPDs and the ultrasound EPDs and use them all in conjunction until the technology is proven. I wouldn't use a bull unless he was positive with both actual and ultrasound EPDs. I'll put my faith in the bulls that do well in both systems."

But, Rouse is bullish enough to believe that producers can use only ultrasound EPDs with confidence.

"We think the most powerful numbers a producer can use are EPDs. And, other than a very few cases, the ultrasound EPDs and progeny test EPDs will give you similar answers."

At least that's true of the Angus data, and it's the expectation for other British breeds. Fact of the matter is, Rouse says the later maturity pattern of Continental breeds - less fat at a year of age than British breeds - might make ultrasound evaluation of Continentals a tougher nut to crack, but the jury is still out.

Of course, the most accurate numbers in the world won't help someone who doesn't understand what they can and can't do. For instance, Pelton explains, "You can describe a bull's composition with individual data, but we like to use it more as a way to describe sire groups."

In other words, individual ultrasound information offers a ballpark description but has limited value when it comes to selecting for specific carcass progress.

Capturing Lost Opportunity Of course, just getting close might be worth the effort.

"What I've tried to tell producers over the years is if we can just eliminate the outliers, get rid of the small ribeyes that lead to Yield Grade 4 and 5 carcasses and get rid of the cattle so lean that they grade Standard, then I think the industry can live with Select and Choice carcasses," says Loren Jackson. He's director of herd improvement records for the International Brangus Breeders Association (IBBA).

Rather than establish EPDs with progeny carcass data, IBBA was one of the first organizations to embrace ultrasound-based EPDs five years ago. The organization continues to gather and analyze all of the data that flows into their system.

"We think if this (CUP) continues to grow, in three years' time, on all of the cattle that go to slaughter, we can reduce outside fat by 1/10th of an inch and maintain the same degree of marbling. Or we can increase marbling by one degree and maintain the same degree of outside fat," says Rouse.

Either way, he explains, the added value and cost savings of such a transition would be worth $1.36 billion to the beef industry each year.

Adds Crouch, "If we are going to improve our product, if we are going to achieve consumer satisfaction, we will have to be able to evaluate more cattle for carcass merit. If not with ultrasound technology, how? If not now, when?"

Fly control is a coordination game

Most cow/calf producers - about 81%, according to a 1997 report from the Animal and Plant Health Inspection Service (APHIS) - use some method of fly control. But only a small number have a well-managed program.

Cost, timing of control method and the inability to implement an adequate program due to lack of facilities or cattle spread out on range are the most common reasons cited for flies not being adequately controlled.

When setting up a fly control program for a customer, the first thing I show them is the fly number profile for the entire five to six months of the fly season. Although most producers realize that fly numbers peak in June, they don't realize there is also another peak in August, long after most control methods have been forgotten and the efficacy of the insecticide used has been drastically reduced.

In recommending programs, I try to coordinate the timing of the application of fly control to be as close as possible to June to give the best results. However, branding calves and sorting cows for the range may be done earlier, and producers do not like to handle cows and calves again just for fly control. Often, this timing is not possible because cattle are on range and away from adequate facilities.

Sanitation Is The Key Element In any fly control program, sanitation is the key element. Eliminating breeding places in manure, spoiled or rotten feed, and stagnant water is half the battle. Fewer adults means fewer eggs to turn into more adults. It takes stable fly larvae only 14 days to develop into adults. House fly larvae need only 10 days.

In proposing fly control programs, my first recommendation is to get an initial kill on the adult flies. If we don't knock down the adults, then the other methods will be overwhelmed and not give the desired results.

This is the major reason why most fly control methods fail. I recommend either spraying the cows or using pour-ons to achieve this initial kill. Buildings and corrals also may be sprayed to lower the adult population.

The next step is to determine another method of control. I always recommend at least two different methods. The use of a larvacide in a mineral is my method of choice for these fundamental reasons:

* Larvacides may be fed free-choice and may be used in most range conditions. Mineral feeders may not be allowed on some grazing permits, however.

* Larvacides fed in this manner do not require handling of the cattle.

* Larvacides act on a different stage of the fly life cycle (acting on the larva stage rather than the adult fly). No known resistance has been shown.

* I like to have some minerals available for both the cows and calves when the grass starts to mature later in the season and may be deficient in some vitamins and minerals.

Back Rubbers And Dust Bags Back rubbers and dust bags are also good methods of fly control that may be used around watering places and don't require much labor or expense. Mister-sprayers or foggers may be used around places where cows congregate to help reduce the adult flies. Fly tags may be used but need to be put on at the right time for best results. Be sure to use two tags instead of just one.

The 1997 APHIS study cited above found that of the 81% of cow-calf producers using some method of fly control, topical products (dust bags, dips, sprays, back rubs) were the most common form (61%) of fly control. Ear tags at 32% came next, then sprays/foggers (23%). Ranchers seldom used biological control, which reflects the transitory nature of the cow herd.

After initiating a fly control program, both the producer and I monitor fly numbers. Some producers think there should be no flies on the cows. Regardless of the methods used or the number of methods used, we will never be successful in eliminating all flies.

Our goal is to bring fly numbers below an economic threshold (generally fewer than 200 flies per animal). But we must take into consideration both the cost of control and the potential loss of production if no control is practiced.

One common misconception about fly control is that the insecticide itself may cause the flies to become resistant to insecticides. Mutant strains may develop but, as of now, are not commonplace.

Pesticide resistance may be better defined as the increasing ability of a pest population to survive exposures to the insecticide being used. This occurs when the more susceptible or weaker individuals in the population die, lea ving behind the stronger, more resistant individuals to produce eggs and further the more resistant flies. This is why producers should alternate insecticide types every year and use different types of insecticides within the fly control program.

Knocking down the adult fly population, practicing good sanitation, alternating fly tag and other insecticide types (pyrethoid or organophosphate), timing the control measures to coincide with both peaks of the fly population (June and August) and using multiple methods of fly control should be integral parts of setting up any fly control program.

Dave Wieland is a consulting nutritionist specializing in the cow/calf and feedlot segments. His client base is primarily located in the High Plains, Mountain States and Northwest. Based in Shepherd, MT, Wieland also publishes a subscription newsletter. For more information or answers to production questions, contact him at 406/373-5512 or e-mail at dwieland@mcn.net.