The economics of feed efficiency — the case for RFI


Source: Alberta Agriculture and Forestry,

Feed costs represent up to 70% of the production costs in a beef operation and it only makes sense that feed efficient cattle should be more profitable. Residual Feed Intake, or RFI is a trait that explains the difference between what an animal is expected to eat and what it actually eats for a given body weight, growth rate and body composition. Because RFI is moderately heritable (35-40%), we can make genetic progress by selecting for cattle with negative RFI who also have desirable growth, carcass merit, fertility and lifetime productivity. This allows us to get paid for the outputs of calf or yearling weight and/or meat yield, yet allowing us to save on feed costs, especially for our females back at the ranch. It’s a win-win! We’ll produce efficient, productive cattle on fewer feed related resources plus those cattle with negative residual feed intake (-RFI) are known to produce less manure and have lower methane emissions making them more environmentally sustainable, a definite benefit for our social license.
Profit drivers for the cow ranch and the feedlot are closely related. For the cow herd, how much she eats, early season breeding, her calf weaning weight and stay ability are very important. The top factors affecting profitability of feedlot calves are related to feed to gain ratio (43%), market or grid value (39%), carcass weight (18%) and animal health (1%), so you should be just as concerned over feed efficiency as you are with the market price.

The Feed Efficient Sire

In animal breeding, response to selection is based on intensity of selection (i), accuracy of selection (r), genetic standard deviation (SD) and generation interval (L) or genetic change = (i x r x SD)/L. The annual rate of genetic response, when we consider the entire herd over many generations, is over-estimated, since cattle breeders will select for multiple traits or use multi-trait selection indices. Keeping this in mind, let’s look at some simplified examples:

Compared to an average bull with RFI=0, Bull A will sire calves that eat less while Bull B will sire calves that eat more for their performance when mated to the average (not selected for RFI) group of cows. With simplified calculations for an estimated breeding value (EBV), you may expect:

These calves will, on average, eat 0.30 lbs less feed on a dry matter basis each day. On a typical 2014 priced forage based backgrounding ration for 115 days, costing $0.065/lb/day or $0.14/kg/day DM basis, this set of calves saves you $2.24/head in feed. Replacement heifers retained from this sire save you the $2.24/head during the backgrounding phase, plus an additional $7.12/head/year in feed meaning these heifers were $9.36/head cheaper to raise to first calving in feed costs alone compared to an animal with EBV for RFI=0.

Compared to Bull A, the replacement heifers of Bull B cost you $16.22/head more to feed from weaning to first calving.

The Feed Efficient Replacement Heifer or Bull Calf

As a breeder, if you have selected for feed efficient females, like a daughter from Bull A, and you mate her to a –RFI bull, more genetic progress in feed efficiency will be made resulting in additional savings in feed costs. Remember, this is not about single trait selection for feed efficiency, rather, you need to consider RFI as an additional trait with your typical breeding goals.

Bull C RFI= -1.06 x 0.4 heritability = -0.42 lbs DM/day

Replacement Heifer (purebred daughter of Bull A) RFI= -0.29 x 0.4 heritability = -0.12 lbs DM/day

Progeny expected (average of the parents) -0.42 + -0.12 = -0.54/2 = RFI -0.27 lbs DM/day

This calf will save you $1.84/head in feed costs starting at weaning to raise it to a yearling. Plus, each year they are in the herd (feed savings of $6.40/head/year) and are mated with superior feed efficient animals you continue to realize feed savings over cattle not selected for RFI.

The Feed Efficient Feeder Calf

Being able to source cattle with improved Feed:Gain as a result of selection for -RFI parents will yield significant feed savings in the feedlot or backgrounding lot. Because RFI is not correlated to growth,( ie ADG) you will not have to give up gain for the reduced feed intake.

Using actual calf RFI values and 2014 feed prices with barley worth $165/tonne on a 77 day backgrounding ration with an ADG of 2.15 lbs/day the most inefficient calf in the pen (RFI= +2.8) cost $29.58 more to get to 700 lbs than the most efficient calf (RFI= -3.6). While those are the extreme RFI values in a group of calves, the following example using actual data also yields impressive results in feed savings at $7.40/head over the 246 days or $11.35/hd/year (taken from J. Basarab, Alberta Beef Industry Conference, Red Deer, 2014).

Pen 1. 600 head on feed for 246 days average RFI= -0.082 kg dry matter/day with average feed costs of $1.95/hd/d and Feed:Gain = 6.80 lbs or 3.10 kg

Pen 2. 600 head on feed for 246 days average RFI= +0.068 kg dry matter/day with average feed costs of $1.98/hd/d and Feed:Gain = 7.13 lbs or 3.24 kg

The Feed Efficient Cow Herd

Feed cost savings will be realized after years of purchasing –RFI bulls and retaining superior RFI heifers for breeding. Additional benefits from improved RFI cattle that speak to your social license and environmental sustainability include: reduced methane emissions of 20-30% and reduced manure production of 10-20%, in addition to improved Feed:Gain by 10-15%.

1.Cow on left RFI= -2.64 kg as fed/day

2. Cow on the right RFI= +2.83 kg as fed/day

These 730 kg (1600 lb) cows are expected to eat about 2.2% of their body weight on a dry matter basis. Their feed consumption on a typical forage based ration would amount to 18.8 kg (41.4 lbs) as fed.

1. If you selected for the –RFI cow and her progeny and have other females like her in your herd, plus purchased –RFI bulls to breed her and her progeny to, you would have realized;
Estimated breeding values in a simplified way to determine the genetic effect of the parents
Cow RFI= -2.64 kg x heritability of 40% = -1.06 kg/d
Bull RFI= -1 x heritability of 40% =- 0.4 kg/d; therefore the progeny are expected to perform at
(-1.06 + -0.40)/2 thus EPD RFI=- 0.73 kg/d
2. If you selected for the +RFI cow and her progeny and have other females like her in your herd and you did not search out –RFI bulls, thus RFI=0 on your bulls.
Estimated breeding values in a simplified way to determine the genetic effect of the parents
Cow RFI= 2.83 kg x heritability of 40% = 1.13 kg/d
Bull RFI=0 x heritability of 40% = 0; therefore the progeny are expected to perform at RFI= +0.57 kg/d
-0.73 + 0.57 = 1.3 kg/head/day less feed for the -RFI selected herd in 2014 feed prices with forage based cow rations priced at $0.12/kg multiplied by 365 days = $56.94/cow/year

The feed differences in the two scenarios would mean a significant feed savings of close to $60/cow/year. Put another way, this 5 to 10% improvement in feed efficiency translates into having your current land and feed resources but being able to run 5 to 10 more cows for every 100 cows you now have.

The above actual real Alberta examples show that finding a breeder who has RFI tested cattle has economic benefits. After setting your typical breeding goals for your cow herd plus looking at bull conformation, semen test, EPD’s and expected purchase price in addition to RFI, you can make improvements on the ranch that include reduced feed costs and improved feed:gain in the progeny regardless of being backgrounded, put on pasture, retained as replacement heifers or put in a finishing lot.

The Value of the RFI bull test

If you breed purebred cattle and want to measure feed efficiency in your superior conformation and performance bull calves, a standard bull test for 20 head costs about $7000.00 or $350/head at the Cattleland National Bull Evaluation Centre, in Alberta (based on 2011 costs from Cattleland Feedyards Ltd).

The bull test for RFI requires at least 70 days on the GrowSafe individual feed intake monitoring system in addition to approximately 3 weeks on a start up ration. Costs are estimated at 2011 values to be $590/head based on a 20 head minimum. The difference of an RFI test over the standard bull test is about $150 – $250 depending on services provided during the test.

Through an RFI test, not only have you identified the superior genetics of the feed efficient bulls to build more efficient cow herds, but –RFI bulls are likely to sell for a higher value compared to the feed inefficient bulls. The Midland Bull Test Station in Columbus, Montana, which can test over 1200 bulls per year, collected data from their annual sales of RFI tested bulls over many years and found –RFI bulls brought up to $300 per head more than bulls with +RFI scores.

Sourcing RFI tested cattle for genetic improvement in your herd and culling the bottom 25 to 30% of your inefficient cattle will take you a long way to saving feed costs, increasing live animal value and building a more sustainable cattle population.

This is the second in a series of fact sheets written by Dr. Susan Markus, the other titles are:

“Making Progress with RFI” and “Frequently asked Questions about RFI”

For further information on feed efficiency go to Alberta Agriculture and Rural Development’s home page to search for RFI curriculum for cattle producers. Additional information can be found at and


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