Funston looks at developing heifers
With beef cattle numbers in the United States continuing to dwindle, input costs rising and calf prices at record highs, scientists are putting more emphasis on finding ways to replace those valuable cows at an economical cost. With beef demand on the increase, the industry is concerned with how they will replenish the factory and maintain the supply of beef.
“The price of admission into the beef industry right now is pretty prohibitive, especially with the economic recession we are currently in,” according to Rick Funston, beef cattle reproductive physiologist with the University of Nebraska. “Despite that, we are producing more beef with a cow herd the size it was in the 50s. That trend can’t continue forever. We need to replenish our cow herd or shrink our industry.”
“We already have excess space in the packing plants and feedlots,” he added.
Low cost development
One possibility Funston shared, during a recent University of Nebraska webinar on developing replacement heifers, is developing replacement heifers at a lower cost.
“Rather than take a significant discount on a heifer at weaning, there is the potential of making a larger profit by growing that heifer,” Funston explained. “The price between a heifer and a steer at slaughter is at a premium for a heifer on a grid because the heifer will grade better. There is the potential to make additional profit by feeding those open heifers.”
The heifers can be developed and bred early, he explained. The open heifers can be sold at a premium in the fall as yearlings.
“Many times, those open yearling heifers can be worth just as much as a bred heifer in the fall,” he said.
Selecting replacements
When selecting heifers to keep for replacements, Funston said producers should cull daughters from the “bad mark” cows.
He considers “bad mark” cows as those that need assistance calving, calve later than 42 days, fail to wean a calf or wean a lightweight calf and have big teats or attitude problems.
He encouraged producers to consider selecting daughters from the oldest cows in the herd.
“Many people think the best genetics are in the younger animals,” he explained, “but the older cows in the herd have the best fertility.”
Traditionally, producers have been told heifers need to be at least two-thirds of their mature weight going into breeding, or there could be problems getting them bred. However, Funston shared some trial data indicating that heifers at 50 to 55 percent of their mature weight can conceive, if they are on an increasing plane of nutrition at breeding.
“Do the math,” Funston said. “At 60 percent of mature weight at breeding, starting with a 500 pound weaned heifer calf, which is not large by today’s standards, we have a lot of time to get them to the target weight. A heifer rarely needs to gain more than 1.5 pounds per day. You don’t have to push them to get them bred.”
Management
Funston was interested in how the management imposed on these developing heifers influenced their longevity in the herd.
Looking at a USDA Meat Animal Research Center study, Funston said the developing heifers that were more challenged during development had more of them still in the herd when they were five years of age.
He explained, “If you expose the heifers to whatever they will have to live on as a cow as early as possible, it will make them a better cow. What they are fed when they are developed is important to their longevity in the herd.”
Research conducted in Minnesota studied heifers that were fed until they reached a body condition score of seven or five, restricted until they stopped cycling, and then fed until they started to cycle. The fat heifers had to achieve a full condition score greater than the heifers that were maintained at a moderate condition before they would cycle.
“If heifers are over fat at first breeding to achieve a high reproductive rate, they may be dependent on a certain amount of fat to breed back as a two- or three-year-old. They may not breed back at all,” he explained.
Low input heifers
In their research in Nebraska, Funston said every heifer is kept and has an opportunity to be in the herd, but they have to do it on a low input development system and a short breeding season.
In a trial comparing heifers developed in a drylot with those developed on cornstalks, the heifers developed in a drylot were 110 pounds heavier at breeding. The heifers developed on cornstalks gained just under a pound a day, but when they all went to grass, the cornstalk heifers gained 0.4 pounds more a day than the drylot heifers.
“With the drylot heifers, you put more feed and yardage into them, but they don’t do as well when they go to grass,” he said. “Green cattle perform better on green grass.”
“When we pregnancy checked these heifers, their pregnancy rates were similar. However, the stalk heifers gained more weight during the summer grazing period. In the end, we put a stalk heifer into the system for a $100 less,” he said. “That is a considerable savings given today’s feed costs.”
“Cattle were put here to graze,” Funston continued. “These heifers will go on to be better foragers. They will graze better in the summer, and producers will get better performance from them than the heifers that were developed in a drylot.”
Consider synchronizing heifers
University of Nebraska Beef Cattle Reproductive Physiologist Rick Funston urged producers to take advantage of heifer synchronization methods to put even more value into replacement heifers.
In a University of Nebraska trial, heifers were developed on winter range or corn residue with minimal supplementation. In the spring, the heifers were synchronized with natural service. The bulls were turned in, and five days later, the heifers were given an injection of prostaglandin.
In a cycling herd, 25 percent should be pregnant by the time the prostaglandin is given.
“Giving the prostaglandin will not make the pregnant cows abort, provided they are five days or less pregnant,” Funston stressed.
The remainder of the cows will cycle over a five-day period. With this synchronization system, bull-to-cow ratios are similar to non-synchronized systems.
“In our work, we use one to 20 for yearling bulls, and one to 25 for older bulls,” he said.
Synchronization with natural breeding can also be a good intervention for ranchers who don’t start calving until May or June. Funston has seen a decrease in pregnancy rates in challenged animals, like heifers, that graze year-around and don’t calve until May.
“I think part of the problem is that feed quality drops off later in the breeding season, so the heifers quit cycling,” he said. “By synchronizing these heifers, more of them will breed in the beginning of the breeding season when the feed quality is likely to be greater.”
“If cattle are not cycling, synchronizing with an injection of prostaglandin will not be effective. Other interventions such as supplemental nutrients, like protein and possibly an ionophore, may help correct a nutrient deficiency in forages declining in quality,” Funston added.
If producers synchronize their heifers and use natural service, they could have the advantage of cows that will calve earlier in the calving season.
“If a cow calves within the first 21 days the first nine years of her life, she will have the equivalent of 1.5 to two more calves than her later calving counterparts,” he explained. “The factory costs the same, but the output can be very different.”
“A single shot of prostaglandin can return $50 today, and possibly allow for a shorter breeding season,” he said. “With today’s low cow numbers and high cattle prices, it is not advisable to greatly shorten your breeding season, but rather have your veterinarian identify later pregnant animals and market them. A pregnant animal is generally worth more money than a non-pregnant animal, regardless of breeding date. An exception may be an open yearling heifer.”
For more information, Funston can be reached at 308-696-6703 or rfunston2@unl.edu. Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
