Bull selection more than just getting the winning bid

by Thayne Cozart

February 26, 2008 10:52 am

— Selecting the best bull for your beef enterprise is a lot more complicated than getting the winning bid, writing the check, and letting the new bull out of your trailer at home.
Twig Marston, KSU Extension beef specialist, told cattlemen attending a crop and livestock school in Cottonwood Falls, Kan., recently that bull selection requires careful evaluation if the bull is to make a positive impact on your bottom line.
“First, you’d better understand your enterprise’s profit center,” Marston said, “and that means you’d better know where you are and where you want to go with your beef business.” He was talking about such things as cow size, grazing management, and end use of the calves—whether you sell them as weaners, background them a bit, feed them out in a feedlot, or sell them as purebreds.
Marston advised to consider the “total package” of the bull and its source. You need to know the answer to such questions as: What breed will work best for you? What’s the breeder’s reputation? What kind of genetics and expected progeny differences are ideal?
“Breeds are different. Some excel in traits you might need, others do not. You need to evaluate breeds that offer probable genetic advancement on the traits you need in your cows and calf crop,” he said.
Bottomline, match the genetics to your needs and resources.
Breeder reputation plays a role in bull selection, according to Marston. How long has the breeder been in business? Has the herd made steady genetic progress through several generations of cows? What’s the demand for the cattle the breeder produces? What about breeder integrity? Does the breeder offer live guarantees, buy back arrangements, delivery services?
“Remember in buying genetics, 90 percent of all genes are the same among breeds. It’s the 10 percent genetic difference that affects selection criteria,” Marston pointed out. “That’s where the EPDs, the performance data, the genetic defects, hair and hide color, and horned/ polled are expressed.”
Marston said cattlemen can have confidence in EPD figures. “A noted Kansas cattleman, Tom Ohlde, maintained that EPDs can make fools out of liars real quickly,” he joked.
He stressed that while EPDs accurately show genetic differences, the biggest EPD bull or most extreme EPD bull may not be the best bull for a specific enterprise.
Marston offered several reminders for cattlemen to keep in mind when evaluating the relative values of EPDs. First, learn the units of measurements of various EPDs. Some are in pounds. Others are in percentages. Still others in dollars.
Also, remember breed associations can vary in the ways they express EPD, but in recent years most associations have used a base year for EPDs, not a floating average. This makes one years’ EPDs easier to compare with other years.
Another index being used is ERTs—Economically Reliable Traits, which are expressed in percentages. Still another is Selection Index, which is listed in dollars.
Marston showed an example where one bull’s selection for a 15-pound weaning weight advantage would add $360 per year in added genetic income for every 20 cows in the herd.
Another example showed selecting a bull with a five percent difference in calving ease EPD saved $75 per year in calving cost per 20 cows.
In a third example of selection for dollars of carcass value, one bull with a $20 advantage in carcass value, improved profit $400 per year for every 20 cows.
Using the same 20 cow example, Marston showed a properly selected bull could affect profits on a sell-at-weaning enterprise versus a retained ownership enterprise. The right bull selected for a positive weaning weight EPD, on the weaning enterprise could add $1,740 in genetic value to his calves, using the bull through four breeding seasons.
By contrast, a bull selected for positive carcass value and feedlot performance could add $1,900 to the bottomline, again used over four breeding seasons.
A relatively new factor in bull evaluation and selection is DNA testing or gene marking. It’s a part of the beef business still in its infancy, Marston said. Three new companies in the field are Gene Star, IdentiGene and MMI. Each company has its own criteria for identifying important commercial genes, he said.
In cow herds producing crossbred calves, Marston said the importance of bull breed selection takes on added significance. A rule of thumb for hybrid vigor is that the widest genetic disparity between the cows and the bulls will express the most hybrid vigor.
But, he cautioned, there are many more factors to consider when buying a bull for crossbreeding, such as mature cow size, birthing ease, ability to utilize forages, etc.
When comparing EPDs generated across breeds, use Angus as a baseline of zero, with other breeds indexing above or below the Angus baseline.
Marston noted there is a difference between heritability and heterosis for various traits. Reproductive performance is low in heritability, but high in heterosis “kick.” Growth rate is medium in both heritability and heterosis. Carcass value is high in heritability, but low in heterosis “kick.”
In general, bull selection, plus crossbreeding, work together to elevate overall performance in the herd.
While genetics are important in bull selection, so too is physical appearance and attributes. Marston advised to “check under the hood before you buy.” Important conformation traits for the new bull is a semen test, deformities, feet and legs, eyes, and the udder of the mother cow.
Testing for high quality semen can really affect conception rates in cows. In one test, satisfactory classified semen resulted in an average 60 percent conception on first service versus an average 30 percent rate on bulls with unsatisfactory quality semen.
Scrotal circumference is one of the best indicators of a bull’s ability to produce quality semen. At 12-14 months, a large scrotal measurement is 35 cm and a small measurement is 30 cm. At 15-20 months, those comparisons were 36 cm and 31 cm.; at 21-30 months, 38 cm vs 32, and for mature bulls 39 cm vs 34. Larger scrotal size bulls are usually more fertile and tend to sexually mature at an early age.
In managing an adolescent bull, factors Marston said to consider is that the bull weighs 60-70 percent of mature weight, so you’ve got to manage the bull to both grow and serve cows, while maintaining good fleshiness and health.
Prior to the breeding season, manage the young bull to gain 1.5 to two pounds per day for at least 60 days. Expect a weight loss of 100 to 200 pounds during a 60-75 day breeding season. After the breeding season, feed the bulls to regain weight at two to 2.5 pounds per day and to acquire a body condition score of six.
Marston advised that a mature bull in good physical condition can serve from 25-30 cows. A young bull can serve from 15-20 cows. “Don’t just turn your bulls out and forget them,” he said. “Watch the bulls work throughout the season. Replace problem bulls immediately before they can do more harm to your profits.”
For his closing thoughts on bull selection and management, Marston reminded: (1) there’s strength in numbers when considering genetic values; (2) managing for a better end product is desirable if it’s cost effective. and (3) in general, “good cattle are those that do everything well.”

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