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Predicting and Measuring "Doability"

Turkey Track Bar

Well-known member
In light of our recent discussion of pampered vs non pampered, doability (which I think is what we're all really getting at, IMO,) season of calving, profitability, etc. I saw these two articles from Beef Magazine, and thought they'd be "stimulating" reading...

Part 1: Predicting Doability
http://beef-mag.com/mag/predicting_doability/
By Bill Zimmerman

May 1, 2007 12:00 PM


There's something almost mystical about “doability” in cattle. We all think we know what it is when we see it — steers that keep gaining during a Panhandle snowstorm, cows that maintain body condition through a Dakota blizzard — but what really is doability? How is it objectively measured? Can we predict and select for it? Is it economically important?


These are among the questions that brought producers and researchers from across the U.S., Canada and Australia to a Feed Efficiency Symposium in Kansas City in December 2006, sponsored by the National Beef Cattle Evaluation Consortium (NBCEC) — learn more at www.ansci.cornell.edu/nbcec. NBCEC is an organization of animal breeding researchers at Colorado State University, Cornell University and the University of Georgia whose focus is on genetic evaluation of beef cattle.

“We believe that feed intake measures need to be included in national cattle evaluation,” says John Pollak, NBCEC executive director. He says the symposium's goal is to begin to set a national plan, identify existing resources and develop collaborations.

Doability & feed efficiency


Get 70+ beef producers and researchers in one room and you won't find consensus on too many topics. But everyone agreed doability is related to differences in feed efficiency.

Feed efficiency in growing cattle has traditionally been expressed as the feed-to-gain ratio or feed conversion ratio (FCR). FCR is commonly calculated on pens of growing or finishing cattle (total feed delivered to a pen divided by total gain = FCR).

When individual average daily gain (ADG) is computed within a pen of cattle of known sire groups, FCR for sires can be estimated relatively inexpensively. Individual feed intake is estimated using a regression equation accounting for an estimate of requirements for growth or production and body weight maintenance.

“FCR is a commonly reported, gross measure of feed efficiency, but selection for it is related to increased growth and mature weights, and therefore increased maintenance energy requirements,” says Denny Crews, University of Alberta professor in livestock genetics and genomics.

Gordon Carstens, Texas A&M University animal scientist, agrees. “Because FCR is highly correlated with postweaning ADG, yearling weight and mature cow size, it isn't very valuable as a selection tool, but residual feed intake (RFI) is more promising.”

RFI (also called net feed intake) is the difference between actual individual feed intake and the intake predicted by the regression equation. RFI data is very expensive to collect (equipment alone costs up to $175/head), but the potential returns may be significant.

RFI is moderately heritable (0.35 to 0.45) and has very low or no correlation to growth, reproduction and carcass traits. According to Carstens, “RFI is not correlated to ADG and is less influenced by compensatory gain.”

And Crews says, “When we select for RFI, our range in breeding values covers nearly all the variations. I can still find the full spectrum of frame size and ADG.” This allows selection for favorable feed efficiency without affecting other selection criteria important to your management and environment.

Feed efficiency in Australia


Feed-intake studies in Australia began with planned matings in 1992 at the Trangie Agricultural Research Station. The first calves were tested for feed intake in 1994.

Despite the station's location at the edge of the Australian Outback, more than 500 producers attended the first major field day in 1995. Though preliminary and not fully validated, the results “blew them away,” says Paul Arthur, director of the Elizabeth Macarthur Agricultural Institute in Camden, New South Wales (Table 1).

“After the field day, the whole concept took off,” Arthur says. “We didn't have a history of central performance testing in Australia, but the producers started to demand it — before we had reliable data on heritability, etc. So some aspects of the industry moved ahead of the research.”

The result was the development of central test stations, and automatic feeders for collecting individual animal intake data. In 1999, a standards manual (available at http://www.agric.nsw.gov.au/reader/net-feed-efficiency/nfesm.htm) was first developed with guidelines for testing beef cattle for Net Feed Efficiency to produce certified test records. Based on certified individual animal records from research and industry herds, the first trial estimated breeding values for Net Feed Intake (NFI) were released by Breedplan — the Australian and international beef cattle performance recording and evaluation scheme — in 2002 for Angus and Hereford.

Low and high NFI individuals were selectively mated to produce low and high NFI lines of cattle. The results of these selection studies confirm that selection for increasingly different NFI increases the difference between the low and high lines by 0.25 kg/day annually.

There were no differences between the lines in relation to growth traits (birth, weaning and yearling weights), scrotal circumference, pelvic measurement and linear body measurements. Carcass traits (retail beef yield, carcass fat and shear force) also showed no significant differences.

Similarly, maternal and reproductive traits were not different between the low and high NFI lines. Thus, it appears cattle can be selected for low NFI without sacrificing the high-value traits.

Arthur concludes, “The low RFI cows are likely consuming less feed to achieve the same level of productivity as the high RFI cows. At this stage, it looks very promising that selection for RFI works, and has the potential to reduce costs.”

Feed efficiency's role


Dave Nichols, Iowa seedstock producer and NBCEC advisory council chairman, is supportive: “I think this (feed efficiency) is so critical because we have had a paradigm shift in agriculture” as a result of the growth of the ethanol industry on the demand and price for corn.

“We have a couple of options in the cattle business — get serious about feed efficiency and management and the use of byproducts, or else have our conventions in about five years with the lobster fishermen because beef will become a special-occasion-only food. Whatever the cost, we as an industry have to address feed efficiency. The biggest cost we have in raising beef is the feed required for maintenance of the cow,” he says.

While cow efficiency wasn't addressed in the Kansas City conference, the cost savings for growing cattle are estimated to be substantial. Australian data from 1995 showed a AU$65/head advantage for bulls fed 120 days (Table 1.) Crews said data on 1,400 Charolais-sired steers in Canada indicated an average feed savings of 390 lbs. between the low and high RFI groups, with no effect on growth, gain or carcass traits.

“This is a big deal,” says Scott Moore of King Ranch. “While I can get paid some extra for marketing the right cattle on the right grid, with feed efficiency I get to keep 100% of the improvement.”

But not everyone agrees a new emphasis on selection for feed efficiency is warranted. Dorian Garrick, Colorado State University animal scientist, says the often-repeated statement that there's no way to improve efficiency with current EPDs isn't true. He says his work shows focusing on profit rather than biological efficiency using a dollar value index incorporating the current array of EPDs can optimize profit for the producer.

He disputes the contention that the industry must invest in developing an EPD for RFI.

“To me, you want to use all the information you can, not just the little piece that's unexplained by our current predictions (referring to RFI). If we're already doing all the other things right, let's try to fine-tune the last little piece… But, if we're going to invest a huge amount of money on that population to discriminate between differences in RFI, looking at the national industry, there are a whole lot of other activities that will give a much faster and easier return.” Those other industry investments, he proposes, should be focused on reproduction, carcass data, animal health and the healthfulness of beef.

Some individual breeders and genetics firms are already working to provide individual feed intake data on yearling bulls. The industry is at a point with feed efficiency similar to when it was searching for good “spread” bulls that would sire low-birthweight calves without sacrificing growth, Nichols says.

“I can't believe for a minute we won't find those outlier bulls, and we've got to get it done,” he adds.

Bill Zimmerman is a geneticist and purebred producer based in Milaca, MN.

Table 1. Which bull would you rather have? Trait Bull A Bull B
Age (days) 420 404
Start weight (kg) 398 386
End weight (kg ) 581 569
Growth rate (kg/day) 1.54 1.54
Rib fat at start (mm) 4 2
Rib fat at end (mm) 14 11
Expected feed intake (kg) 1,668 1,639
Actual feed intake (kg) 1,585 1,881
Feed Conversion Ratio 8.6 10.2
Residual Feed Intake (RFI) (kg) -82.0 +242.0
Difference in feed cost = AU$65/head on 120 day test.


About the consortium


The National Beef Cattle Evaluation Consortium (NBCEC) was formed in 2001 with congressional funding to improve genetic evaluation programs for beef cattle. NBCEC's six-member board includes animal breeding researchers from the consortium — Colorado State University, Cornell University, and the University of Georgia — with additional members from other universities and USDA. Cornell's John Pollack is the executive director.

An industry advisory board, a who's who of leading seedstock producers and breed association leaders, guides NBCEC's direction and management and is chaired by Dave Nichols of Bridgewater, IA. Learn more about NBCEC at www.ansci.cornell.edu/nbcec.

Part 2: Measuring Doability
http://beef-mag.com/mag/measuring_doability/

Measuring Doability

By Bill Zimmerman

Jun 1, 2007 12:00 PM


Read part one: Predicting Doability>


Most of the efficiency work underway today is focused on growing cattle. While cow feed costs are of overriding importance in integrated beef-production systems, the measurement of forage intake on large numbers of mature cows isn't practical.

“Expectations are that appropriate use of the feed-efficiency trait in growing cattle will generate progeny that are efficient in all segments of the industry,” says Gordon Carstens, Texas A&M University (TAMU). Some projects measure the individual efficiency of growing bulls or heifers, while others test progeny of sires.

While mathematical models, such as the Cornell/Cattle Value Discovery System, are being developed to predict feed intake, actual individual animal feed intake data over a 70+-day feeding period is the key number, along with the standard data on weight, gain, etc. Three different but related efficiency measures are derived from the data: feed conversion ratio, partial efficiency of growth, and residual feed intake (RFI). Discussions about standardization of collection, analysis and reporting of intake on beef cattle are being conducted through both the National Beef Cattle Evaluation Consortium (NBCEC) and the Beef Improvement Federation (BIF).

Two systems commonly used for individual feeding trials are the Calan Broadbent Feeding System and GrowSafe. In both systems, cattle are housed in small groups simulating group-feeding behavior in commercial operations.


The Calan system employs an individual feeding door that is unlocked by a wireless “key” each animal wears around its neck. Each animal has an individual feed trough and data on each feeding event is collected.

Meanwhile, GrowSafe equipment utilizes a shared feed trough in an integrated system that reads an electronic ID ear tag and collects data each time an animal has a meal.


Other systems for successfully collecting individual intake data vary from hand-feeding — using the always dependable, 5-gal. pail technology — to hybrid integrated electronic systems. In Australia, portable units dubbed “meals on wheels” are available for producers to do on-farm testing as part of Australia's national data-collection effort.

Based on an informal NBCEC survey, there's a one-time capacity of about 10,000 head — scattered across the U.S. and Canada — for individually feeding, collecting and analyzing data in growing cattle. Contrast that with an industry that harvests more than 400,000 head of fed cattle/week. Regardless of the system used, however, phenotypic feed efficiency data in cattle is expensive to collect and analyze.

The value of partnerships


Across the U.S. and Canada, partnerships between universities, breed associations, artificial insemination (AI) firms, feed companies and individual breeders make individual and progeny testing for feed efficiency happen. To make the best use of resources, most projects are multi-faceted and collect data on other traits in addition to feed efficiency.


The American Simmental Association (ASA) is in the second year of a multi-year progeny test being conducted at the University of Illinois (UI). Marty Ropp, ASA director of field services, says the feed-efficiency project is part of ASA's annual carcass-merit evaluation of Simmental sires. To date, ASA has data on 50 bulls from the Illinois study, with an average of 15 steer progeny/sire.

Sires are enrolled by ASA member breeders and it's used in large commercial herds that cooperate with ASA on the study. Data is returned to the sire owner and cooperator, and incorporated into the Simmental EPDs and dollar value indexes. The UI facility uses the GrowSafe system and boasts a 960-head capacity.

UI also is cooperating with the American Angus Association (AAA) in a multi-year study involving 800 fall-calving cows bred to Angus sires. The project will include individual feed-intake data on 450 progeny each feeding period and collect comprehensive data on performance, ultrasound, carcass and behavioral traits.

AAA is also in the second year of a five-year project with North Carolina State University (NCSU) on biological efficiency in the Angus cow. Using NCSU's Calan system, the effort is researching methods to identify bulls with efficient daughters and predict efficient replacement heifers. AAA's Bill Bowman says, “We hope these research projects will spearhead future practical data collection and analysis for genetic selection tool development.”

TAMU's Department of Animal Science uses both the GrowSafe and Calan systems, and it has partnered with the Beef Development Center at Millican, TX, to test more than 500 bulls and heifers. TAMU is also working with King Ranch, Camp Cooley Ranch and Kallion Farms in measuring efficiency in their calves, Carstens says. He's also worked with Denny Crews, University of Alberta professor of livestock genomics, in developing the RFI index being used in the TAMU projects.

In Canada, Crews, who also chairs the BIF committee on feed efficiency, conducts projects in cooperation with Canadian Charolais and Canadian Angus, and he relies on support from the Canadian Cattlemen's Association and Alberta Beef Producers, among others. Working with the Olds College bull test, they have nine years of efficiency data on steer and heifer progeny of the high-use AI bulls in Canada.

ABS Global, the most active AI firm in the U.S. in the feed-efficiency area, partners with Circle A Ranch in Iberia, MO, to market top graduates of the Angus Sire Alliance progeny profitability test. Now in its fifth year, this exclusive agreement seeks to progeny-test all Angus sires new to the ABS lineup using Circle A's Calan-equipped, progeny-testing facility. Feed-efficiency data and a related profitability index are available on many ABS Angus sires. Doug Frank, ABS Global beef product manager, says the goal is “to find the profitable outlier bulls for our customers through progeny testing.”

Some of those outlier bulls marketed by ABS carry the “Ironwood” prefix, the moniker for bulls from Wardens Farm in Council Bluffs, IA. One of the pioneers of feed-efficiency testing, Duane Warden has 25 years of data on his unique Angus genetics, and he recently partnered with the Iowa Beef Center (IBC) and others to develop a new hybrid feed-intake monitoring system. Using this system, he's testing 64 Angus bulls annually for feed efficiency.

Iowa State University's Daryl Strohbehn has worked closely with Warden on this new facility. “If producers want to get involved in developing an on-farm test, IBC is definitely available to consult with them and share what we've learned,” Strohbehn says.

Jorgensen Angus of Ideal, SD is another pioneer in feed efficiency. Starting 11 years ago by hand-feeding 21 bulls, Jorgensens now have an extensive on-farm test of their bulls utilizing the Cornell model to predict intake. Their validation work shows that the intake prediction is within 3-5% of actual intake, and the model consistently identifies the top and bottom outlier bulls correctly.


Cody Jorgensen says any breeder can set up an on-farm test, as the data required for using the Cornell model is “nothing you aren't already collecting.” Does it make a difference? “Absolutely,” he says. “By putting emphasis on cow families developed from our efficient sires, we have simply fed less feed — and improved other profit-making traits.”

Bill Zimmerman is a purebred producer based in Foley, MN, and program coordinator for the BEEF Quality Summit, set for Nov. 7-9 in Omaha, NE. Visit www.beef-mag.com for more information.

So, your thoughts?

Cheers---

TTB :wink:
 

Mike

Well-known member
"RFI (also called net feed intake) is the difference between actual individual feed intake and the intake predicted by the regression equation."

Will someone please explain to me exactly how this "Predicted Intake" and "Predicted Gain" is calculated? How accurate is this prediction?
 

Badlands

Well-known member
RFI = Residual Feed Intake =
Observed DMI – Expected DMI(Ŷ) = Y-Ŷ

Ŷ = Expected DMI|Midweight^.75,ADG


Ŷ = β0 + β1*MW^.75 + β2*ADG + εi

OK, OK, enough formulas!



Mike, it is a regression that accounts for body weight (Midweight^.75) which accounts for energy for maintenance and ADG, which accounts for energy for gain.

Basically, it puts downward pressure on FI so that an animal will have the same size and adg as would be expected, but eat less to do it.


Similarly, maternal and reproductive traits were not different between the low and high NFI lines. Thus, it appears cattle can be selected for low NFI without sacrificing the high-value traits.
This line is dubious. It depends if you use the strict scientific definition (alpha= 0.05) , or loosen the standard slightly for exploratory research (alpha = 0.10), or traits that have a larger effect on net profit (an unexplored, but important consideration, in my opinion). The p-value for the trait of interest in this study was 0.07, just outside the value of 0.05 to be considered statistically significant. So, they concluded that there was no significant effect. I take a different tact, and say there is a difference between statistical significance and economic importance, and especially so for the female traits.


Badlands
 

Jason

Well-known member
Mike these tests have been done with real weights. The feed is weighed and they have either individual bunk spaces that will tell which animal is there, or they are in seperate pens, or other methods that you can be assured only the target animal's consumption is measured.

I have seen the plotted graph from The Beef Development Center of Texas where feed consumption vs adg is.

Some of the high gainers were the high consumers, and some were the low consumers.

Some of the low gainers were high consumers and some were low.

Now it has been shown that using the right gain with low consumption results in this trait being passed on. The article says they can identify the high and low outliers, but I don't think they can give exact feed intakes, just close guesses, much as we do now when feeding the cows... they should eat this many bales over this length of time.
 

Mike

Well-known member
Jason said:
Mike these tests have been done with real weights. The feed is weighed and they have either individual bunk spaces that will tell which animal is there, or they are in seperate pens, or other methods that you can be assured only the target animal's consumption is measured.

I have seen the plotted graph from The Beef Development Center of Texas where feed consumption vs adg is.

Some of the high gainers were the high consumers, and some were the low consumers.

Some of the low gainers were high consumers and some were low.

Now it has been shown that using the right gain with low consumption results in this trait being passed on. The article says they can identify the high and low outliers, but I don't think they can give exact feed intakes, just close guesses, much as we do now when feeding the cows... they should eat this many bales over this length of time.

I know how "Feed Efficiency" tests work. We use the "Calan Gates" for measuring feed consumed. I have had the most efficient bull (Ratio wise)on test many times.

My question is.... If the "Net Feed Intake" is based on his actual efficiency minus the "Predicted Efficiency", and as you say, there are outliers and exceptions to the rule, how am I to trust the "Predicted Intake Number"?
 

Northern Rancher

Well-known member
I find a study on doability that is conducted in a feedyard enviroment to kind of be an oxymoron-most good ranchers have done a pretty good job of identifying and propagating the genetics that can function under their management systems. In fact probably your cows with the most doability have big appetites-they are able to cram enough of whatever they are faced with eating into themselves to thrive. If you have the discipline to cull what falls apart mother nature is a pretty good helper at sorting time.
 

Badlands

Well-known member
The predicted intake can be calculated from expectations based on NRC for the weight, gain and type of the animal, or it can be based within the pen of animals that the measurements were taken on. The 2nd method is the one that the tests have used that were referenced in the articles.

The regression equation is fit for all of the animals simultaneously. So, there is an average for each measurement and each animals' predicted intake is a deviation from that average based upon it's own performance.

It is an adjustment, but rather than a WW adjustment based on the whole breeds' averages from historic data, and used on each animal, this would be using the performance within that group to make the adjustments.

Badlands
 

Badlands

Well-known member
I find a study on doability that is conducted in a feedyard enviroment to kind of be an oxymoron-most good ranchers have done a pretty good job of identifying and propagating the genetics that can function under their management systems.

"Doability" was a terrible name for the articles.

In fact probably your cows with the most doability have big appetites-they are able to cram enough of whatever they are faced with eating into themselves to thrive.

It's not that simple. A lot of the high-appetite cows are that way because they are very inefficient at converting grass to performance. A lot of them are good converters, though. The point is that there are both kinds of animals in the mix of appetite. This indicates that there is NO distinct pattern between appetite and "doability".

Badlands
 

Northern Rancher

Well-known member
Doability encompasses so many things though-soundness is a major factor the ability to graze efficiently and travel etc. I just find it hard to see that kind of research coming back to a commercial rancher and truly giving him any benefit. I suppose appetite is a bad term but most of easy doing cows I see have alot of capacity to take in the lower quality feed that they sometimes get by on. MARC did some intertesting stuff on what cows could get bred on the lower quality rations if I remember right Red Polls came out pretty good. probably the best doability research would be to drop a group of cows off and come back in ten years and see what's left-or would that be more evolution than selection.
 

Badlands

Well-known member
Red Polls kicked butt!

They were the ONLY breed that actually got more efficient as they became more nutritionally challenged.

There are a number of "minor breeds" that have been totally steam-rolled that have some real usefulness beyond that of some of the more popular breeds.

Badlands
 
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