Mon Dec 12, 2011 10:37 AM CST: http://www.dtnprogressivefarmer.com/dtnag/home
By Boyd KidwellContributing Editor
Heifers are at the heart of Alan Graybeal’s cow-calf operation. And breeding replacement heifers to calve as 2-year-olds is key to the commercial cattleman’s profits.
Every year, Graybeal develops 40 to 60 heifers as replacements on his farm, near Radford, Va. The goal is to get these heifers bred at 12 to 13 months of age and to calve at 2 years. He breeds some heifers as early as 10 months of age to calve at 19 months.
Calving this early is an unusual management technique, but it works in Graybeal’s case. Here, the cow herd is divided into spring- and fall-calving groups. Heifers bred to calve at 19 months become replacements in the fall-calving herd. Heifers bred at 10 months have a 75% pregnancy rate, while those bred at 12 to 13 months have a 92% pregnancy rate. Graybeal notes the younger set of heifers doesn’t have increased calving difficulties.
Graybeal’s emphasis on early calvers has research behind it, proving the profits are there. A 15-year study out of Oklahoma shows when a heifer calves as a 2-year-old, it means an additional 300 pounds of beef is produced over that cow’s lifetime, compared to calving first as a 3-year-old. Those extra pounds add up for Graybeal’s herd of 350 SimAngus cows.
Laying the Foundation
The groundwork for developing these early calvers begins long before heifers are even weaned. Graybeal uses artificial insemination (AI) and selects sires for balanced traits and moderate frames. He chooses bulls with Expected Progeny Differences (EPDs) for moderate growth and milking ability in their daughters. His goal is moderate-framed heifers that give adequate milk and rebreed with nutrition coming from pastures and hay.
“We avoid extremes in AI sires. If we select EPDs for extremely high growth rates, those heifers may be too large-framed to make it in our grass-based operation. If we select for extremely high milking ability, we may not have the nutrition needed for heavy milk production and on-time rebreeding.”
As Graybeal looks over 160 heifers trying to choose 60 replacements, he leans heavily on the performance records of cows already in his herd.
“We keep many of our heifers from cow families we know have done a good job over the years,” he says.
Graybeal also gives preference during the selection process to the AI-sired heifers, saying these replacements speed up genetic progress of the herd.
Developing on Forage
At weaning time, replacements enter a 45-day preconditioning program along with those calves destined for the feedlot. After this phase, replacement heifers go on pasture, depending solely on forage and high-quality alfalfa hay.
As breeding season approaches, Virginia Tech veterinarian Dee Whittier performs reproductive tract exams on the heifers. Each one receives a reproductive tract score measuring physiological readiness. A score of 1 indicates the heifer has an infantile reproductive tract and isn’t ready for breeding. A score of 5 indicates the heifer is cycling. Heifers with a score of 4 are cycling or probably will be in a few weeks. To conceive early in the breeding season, 12-month-old heifers should have scores of 3 to 5.
Heifers in the Feedlot
While Graybeal relies on forages and hay to prepare replacement heifers, in other regions, feedlots are key in developing replacements. Because of short grazing seasons, Wes Dvorak, of Manning, N.D., develops heifers in his feedlot. He starts at weaning, sorting large-framed heifers from his 250-cow herd. They are finished in feedlots with steers. He evaluates the remaining heifers, keeping 40 for his herd and developing the rest to sell as bred heifers.
“In selecting replacement heifers, I look closely at the performance of the dams and the bloodlines of the sires. Then we cull based on conformation and temperament,” says the North Dakota cattleman.
Dvorak uses a high-roughage ration and shoots for moderate weight gains that allow a heifer to reach a target weight of 60 to 65% of mature weight by breeding season. Ultrasound is used on the heifers after AI to see which are bred and to sex expected calves. Marketing heifers as groups that will have either all bull or all heifer calves is a good sales tool in today’s replacement market.
Advice From a Pro
Patsy Houghton, of McCook, Neb., founded a custom heifer-development facility called Heartland Cattle Company 21 years ago. After managing 80,000 replacement heifers for rancher/clients, the PhD in ruminant nutrition is nationally known as the guru of heifer development.
Here are Houghton’s tips for selecting replacement heifers:
— Match weight with appropriate frame. Depending on feed resources, heifers should mature into cows weighing 1,100 to 1,300 pounds. A heifer that matures at 1,150 pounds should have a high 4 frame score.
— Boost fertility with medium-framed heifers. Taller, larger-framed heifers have a longer growth curve and tend to reach puberty later.
— Take advantage of hybrid vigor. A planned crossbreeding program pays dividends in fertility, growth and longevity.
— Establish a uniform cow herd. Houghton prefers black- or red-bodied heifers. White faces are fine, and pigment around the eyes reduces the chances of pinkeye.
— Select calm heifers. Cattle with quiet dispositions exhibit better fertility, immune response, weight gain and meat quality.
— Vaccinate heifer calves for brucellosis prior to 10 months of age. Heifers vaccinated after 10 months run a risk of showing positive titers for brucellosis as young cows.
— Schedule reproductive soundness exams 35 to 45 days prior to breeding. Houghton finds approximately 5% of otherwise good-looking heifers flunk reproductive soundness exams and should be sent to feedlots.
— Feed to meet target weight and Body Condition Score (BCS). A heifer should reach a target weight of 60 to 65% of her mature weight at the time of first breeding. For heifers that will weigh 1,300 pounds as adult cows, the target weight is 780 to 845 pounds with a BCS of 5.75 to 6.00.
— “Develop your heifers on a high-roughage, limit-fed ration. Heifers developed on a high-roughage diet have a better chance of breeding back under ranch conditions,” Houghton advises.
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