Net feed intake, residual feed intake, residual gain, feed per gain — however you define it, feed efficiency in beef production becomes more critical as feed and other input prices rise. And researchers, seedstock breeders and commercial producers have taken notice, with growing emphasis on producing cattle that will do more with less.
As the industry strives to identify genetic lines of efficient cattle, differences in the ways efficiency is defined and measured can complicate the selection process. One issue is that efficiency alone does not translate into productivity or profits. Think of cattle like employees. Say, for example, a worker finishes in one hour what his coworkers do in two hours. Sounds efficient, but if that’s the only work he does for the day, his employer, who pays him for eight hours, won’t be happy. But if he puts in eight hours and produces 12 hours worth of work, he’s providing a good value.
Likewise with cattle, an animal that eats and gains like a French supermodel won’t make money regardless of how efficiently it turns its meager intake into beef.
For these reasons, Colorado State University animal scientist and genetics specialist Denny Crews, PhD, says he prefers the terms “feed intake” or “feed utilization” rather than “feed efficiency,” which people tend to associate with feed-conversion ratios alone.
Crews and other researchers measure and study feed intake and feed utilization at CSU’s Feed Intake Unit, opened in 2009, with a capacity to monitor individual feed intake on 200 yearling cattle using 24 feeders in six pens. Researchers have completed four tests, with about 750 cattle. “What we’re looking for,” Crews says, “are animals that perform as well or better than others but do so on less feed.”
Among private seedstock operations measuring feed efficiency, they use varying approaches toward applying the information to EPDs and bull selection. Nick Hammett, commercial marketing manager at Circle A Angus, Iberia, Mo., says Circle A has been collecting progeny data for feedyard intake and average daily gain for more than 10 years and using that information, along with data for other traits, in its Angus Sire Alliance selection index.
Rather than use residual feed intake, the efficiency portion of the index combines intake and gains to identify animals that perform well with good feed-conversion ratios, eliminating those with little gain and little intake or high gain and high intake.
Circle A uses a GrowSafe system with a capacity to individually measure feed intake on 200 head of cattle. While Circle A uses that information internally, Hammett points out that the Angus Sire Alliance focuses on progeny testing rather than individual intake measurements to calculate breeding values used in the selection index.
The operation calculates EPDs for post-weaning average daily gain and daily dry-matter intake, but incorporates the calculations into an overall profitability index rather than presenting them individually. In addition to those traits, the index includes breeding values for birthweight, weaning weight and carcass characteristics.
Circle A’s bull customers, Hammett says, are aware the index includes measures of efficiency and are willing to pay premiums for bulls with high ratings for profitability. Most are not retaining ownership through finishing; however, their selection for high-profit calves, including efficiency, adds value at weaning. Many capitalize on the calf buy-back program through Circle A’s cattle-feeding division and know that the operation pays premiums for progeny of their proven bulls.
Leachman Cattle of Colorado, a seedstock producer based near Wellington, Colo., has measured individual feed intake and gains on bulls since 2004. Manager Lee Leachman also says he focuses on intake and feed per gain, looking for animals that combine performance and efficiency. “In any group of 100 or more bulls, we have bulls that eat as much as 31 pounds of dry matter and as little as 15 pounds of dry matter compared to an average daily dry-matter intake of 23 pounds,” he says. “This is a variation of plus or minus 34 percent from the mean. Conversion, measured in terms of pounds of feed per 1 pound of live weight gain, ranges from 4:1 to 10:1.”
Because of the variation in intake and conversion, Leachman says RFI is not the only trait you want. “RFI is a good number in that it makes selection neutral for growth. However, we want growth.” By measuring and selecting for both lower feed intake and higher growth, he says, the system identifies the most profitable cattle that eat less and gain more. “In our model, lower intake cattle get credit for having lower feed costs. Higher growth cattle get credit for having higher output and revenue. We don’t just want feed-efficient cattle; we want profitable cattle. To accomplish this, we select for our $Profit value. This single number is proven to improve revenue and lower costs — thus improving profit. It’s just that simple.”
Passing it on
Geneticists have shown that feed efficiency is a moderately heritable trait, and it seems logical that progeny of efficient bulls — steers in the feedlot and their heifer mates on pasture — should be more efficient.
Measuring cow intake on forage, however, presents a significant research challenge, Crews says. In a couple of studies, researchers have measured performance of steers through finishing, then gone back to group cows based on the efficiency of their calves, looking at maternal traits such as reproduction rates and stayability, or in one study, monitoring intake levels of pregnant cows fed in a drylot setting. In these trials, Crews says, researchers did not find major differences in fertility or other measures between mothers of efficient versus inefficient calves. So, while it is difficult to show a clear advantage for cows on forage, research indicates selection for intake utilization at least has no negative effects on cow performance.
In another trial, Australian researchers collected individual intake-utilization data on yearling heifers, put the heifers into a breeding herd, then brought them in for repeat testing as 4-year-olds. In this trial, efficient feed utilization in yearling heifers correlated well with efficiency in mature cows, suggesting that testing cattle at a young age can predict future performance.
Some evidence suggests selecting for RFI could relate to later heifer puberty. The key point, Crews says, is to avoid selecting for a single trait but rather to include desirable, economic traits in a group of selection criteria.
Progeny testing in feedyard steers is easier to measure, and the benefits of including efficiency measures in genetic selection become clear.
Hammett says that as Circle A finishes calves it buys back from bull customers, feed-to-gain ratios in the feedyard have improved over time, as including efficiency in selection gains influence in customer herds. Pounds of feed per pound of gain averages “in the low 5s,” he says, with gains around 3.5 pounds per day. Among cattle from the buy-back program, 98 percent grade Choice or Prime, with 40 percent qualifying for the Certified Angus Beef program.
Leachman Cattle of Colorado recently completed a large progeny feeding trial with Decatur County Feed Yard, Oberlin, Kan., involving 450 Angus steers. After a 70-day warm-up period, the feedyard weighed and sorted into sire groups. After 84 days, the feedyard weighed the calves again and calculated gain, dry-matter intake and feed to gain. Leachman then compared the feedyard results with the sire EPDs for feed efficiency and their accuracy, which were calculated before the progeny data were available (see table below).
Using a multiple-sire set of 198 Angus calves without feed efficiency EPDs as a baseline, the data show how progeny of known sires compare. “As you can see, our feed-per-gain EPDs line up extremely well with the actual feed-to-gain results,” Leachman says. “In fact, this is almost uncanny and probably is beyond what we can actually expect on an ongoing basis.”
The value differences in cost of feed are in the final column of the table. Leachman notes these are based on feeding a 600-pound steer to a 1,250-pound finished weight. The figures assume a current dry-matter ration cost of $315 per ton. Between the progeny of the most efficient sire, Leachman Paradigm, and those from the least efficient sire group in this test, there is a difference of $164 per head.
Need for more data
Crews says the national database of cattle tested for feed intake and utilization totals around 15,000 to 20,000 head, but ultimately that tested population will need to grow and data become standardized for the measure to become more widely used in selection indices. “Ideally,” he says, “EPDs for RFI or some measure of intake utilization will be incorporated into a selection index with other economically important traits.”
As producers consider efficiency data in their bull selection, Crews advises them to know where their income and costs come from. For a producer who sells calves at weaning and purchases replacement heifers, feed intake probably isn’t the highest priority in bull selection. Eventually, the market could evolve to offer premiums for calves carrying certification of their genetic potential for efficient feedlot gains. But for now, the best opportunity is for producers who retain calves through finishing to capture more value in lower cost of gain. For producers who raise their own replacement heifers, he adds, including RFI among their selection criteria might allow them to run more cows on the same acreage or feed less supplements.
In any case, Crews believes savings over time will more than pay for collecting the data and building intake utilization into a comprehensive selection strategy. One piece of evidence that’s hard to ignore, he says, is that some of the most progressive ranches, run by the most astute managers, are on top of this. They’re already fully engaged in building better intake utilization into their herds.
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