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Feed Efficiency, RFI and the
Benefits for the Beef Industry
J.A. Basarab, P.Ag., Ph.D. Alberta Agriculture and Rural Development
Lacombe Research Centre, Alberta, Canada
Tiffin Conference, Cattle Gate to Dinner Plate
19 January 2012, Lethbridge, Alberta
Feed Efficiency in Beef Cattle: Why?
56-71% of total cost of production for cow-calf operations
is associated with feed, bedding and pasture
(Alberta Agriculture and Rural Development 2005)
65-75% of the total dietary energy cost in breeding cows
is required for maintenance (Ferrell & Jenkins 1985; NRC 1996)
Genetic improvement in feed efficiency - estimated:
$50-100 million annually to Alberta’s beef cattle industry
Energetic Efficiency in growing beef cattle
1. Feed Intake
2. Feed Conversion Ratio: DMI/ADG;
CV for DMI, 8-12%; CV for ADG, 16-20%
3. Partial Efficiency of growth: ADG/(avg. DMI-expected DMIm)
efficiency of growth after removing FI for maintenance
4. Relative Growth Rate: 100 x [log end wt – log start wt]/days on test
Growth relative to instantaneous body size
5. Kleiber Ratio: ADG/avg test period LWT 0.75
weight gain per unit of metabolic body weight
All measures are related to body size, growth
and composition of gain
Maintenance requirements of beef cattle is largely
unchanged over last 100 years (Johnson, Ferrell and Jenkins, 2003)
CH4 NH3 N2O GWP100
Chickens – layers -30 -36 -29 -25
Chickens – broilers -20 10 -23 -23
Pigs -17 -18 -14 -15
Cattle – dairy -25 -17 -30 -16
Cattle – beef 0 0 0 0
Sheep -1 0 0 -1
% Change in greenhouse gas emissions and global
warning potential achieved through genetic
improvement (1988-2007)
Sources: Project for DEFRA by Genesis Faraday Partnership and Cranfield University
(AC0204) from Hume et al. (2011), J. Ag. Sci., doi:10.1017/S0021859610001188 .
Pork 2.8-4.5 kg CO2e/kg pork; chicken 1.9-2.9 kg CO2e/kg chicken; Dairy 1.3 kg CO2e/kg milk
Beef 18-36 kg CO2e/kg beef
Calf-fed, Hormone FreeAn imal GHG emissio n s = 9 2 2 ,1 0 7 k g CO2 e
Figure 1. Breakdown of total greenhouse gas (GHG) emissions resulting from hormone free and growth implanted
calf-fed and yearling-fed beef production systems (CO 2 equivalents, 160 cow-herd assumed).
Calf-fed, growth implantedAn imal GHG emissio n s = 9 2 8 ,3 4 4 k g CO2 e
Yearling-fed, Hormone FreeAn imal GHG emissio s = 1 ,2 1 9 ,6 5 9 k g CO2 e
Yearling-fed, Growth ImplantedAn imal GHG emissio n s = 1 ,2 3 7 ,0 8 2 k g CO2 e
Total GHG emissions include methane from enteric fermentation and manure, nitrous oxide from manure, carbon dioxide from energy use and nitrous oxide from cropping.
Productive cow
70.0%
Productive cow
69.6%
Productive cow
53.0%Productive cow
52.2%
Feeder 15.1%
Replacement bulls 1.3%
Spring culled cows 3.9%
Fall culled cows 3.1%
Replacement heifers 3.4%
Herd bulls 3.5%
Feeder 14.5%
Replacement bulls 1.3%
Spring culled cows 3.9%
Fall culled cows 3.2%
Replacement heifers 3.4%
Herd bulls 3.6%
Feeder 35.4%
Replacement bulls 1.0%
Spring culled cows 3.0%
Fall culled cows 2.4%
Replacement heifers 2.6%
Herd bulls 2.7%
Feeder 36.3%
Replacement bulls 1.0%
Spring culled cows 2.9%
Fall culled cows 2.4%
Replacement heifers 2.5%
Herd bulls 2.7%
37 131
8 17 134
17560
9 316
049
3 61 827
1 16 328 9 8124
8 4 43 86 597
928 20 24
9 54 643 31 15 16
5 1 5
Bull ID
-5
-4
-3
-2
-1
0
1
2
3
4
RF
I, k
g a
s fe
d/d
ay
+RFI Mid RFI -RFI
Olds College; 96 British bulls (2003-05)
Cost difference: -RFI vs. +RFI
3.0 kg as fed/day x $0.15/kg x 140 days = $63
Diet (as fed basis): 76% barley silage; 30% barley grain & 3% beef sup. (32 % CP)
Residual Feed Intake (RFI) also called Net Feed Efficiency:
FEED INTAKE ADJUSTED FOR BODY SIZE AND PRODUCTION - growing cattle
is the difference between an animal's actual feed intake & its expected feed
requirement for maintenance of body weight, growth and changes in fatness.
- moderately heritable
(h2 = 0.29-0.46)
- reflects an animal’s
energy requirement
for maintenance.
Energetic Efficiency in growing beef cattle
148 steers from 5 genetic strains fed a finishing diet and gaining 1.52 kg/day . No relationship to slaughter
weight, hip height and gain in hip height (Basarab et al. 2003).
rp = 0.00
P = 0.99
rp = 0.00
P = 0.99
Selection for low RFI will:
1. Have no effect on growth & animal size Phenotypic (rp) & genetic correlations (rg) are near zero Arthur et al. 2001; Basarab et al. 2003; Crews et al. 2003; Jensen et al. 1992
2. Reduce feed intake by 10-12% at equal body size & ADG rp = 0.60-0.72; rg = 0.69-0.79 (Arthur et al. 2001; Basarab et al. 2003, 2007,
2011;Herd et al. 2002)
-2 -1.5 -1 -0.5 0 0.5 1 1.5
Residual feed intake, kg DM/hd/day
5
6
7
8
9
10
DM
I, k
g/h
d/d
ay
73 hybrid bulls
Olds College,
Fall 2006
rp = 0.64
3. Improve Feed Conversion Ratio (FCR) by 9-15% at
equal body size & average daily gain rp=0.53-0.70; rg = 0.66-0.88; Arthur et al. 2001; Basarab et al. 2003, Herd et al. 2002
148 steers
rp = 0.43
Lacombe
-5 -4 -3 -2 -1 0 1 2 3 4 5
RFI, kg as fed/day
3
4
5
6
7
8
FC
R,
kg D
MI/k
g g
ain
4. No effect on carcass fat provided RFI is adjusted
for fatness (Basarab et al. 2003; Nkrumah et al. 2007)
Phenotypic (rp) & genetic correlations (rg) are inconsistent
& near zero (0.20 to –0.20)
Classical Serial Slaughter Study: Total whole body composition (water, fat, protein, ash
& energy); MEI = Retained energy + Heat Production
Liver weight: 7.8% LOW RFI (P=0.007)
Stomach complex: 7.6% LOW RFI (P=0.004)
Heat production: 9.3% LOW RFI (P<0.001)
5. Lower heat production by 9-10% (MEI=RE+HP; HP=NEm + HIF)
Basarab et al. 2003; Nkrumah et al. 2007
1.00
1.20
1.40
1.60
1.80
2.00
2.20
2.40
2.60
2.80 8.5
- 9
.0
9.5
- 1
0.0
10.5
- 1
1.0
11.5
- 1
2.0
12.5
- 1
3.0
13.5
- 1
4.0
14.5
- 1
5.0
15.5
- 1
6.0
16.5
- 1
7.0
17.5
- 1
8.0
18.5
- 1
9.0
19.5
- 2
0.0
20.5
- 2
1.0
21.
5 -
22.0
22.5
- 2
3.0
23.5
- 2
4.0
Time (0.5 hr)
Oxyg
en
co
nsu
mp
tio
n (
L/
min
)
LOW or -RFI
MEDIUM RFI
HIGH or +RFI
6. Lower methane emissions by 15-30% &
manure production by 15-20% Okine et al. 2001; Arthur et al. 2002; Nkrumah et al. 2007; Hegarty et al. 2007
0.000
0.040
0.080
0.120
0.160
0.2009
.0 -
9.5
10
.0 -
10
.5
11
.0 -
11
.5
12
.0 -
12
.5
13
.0 -
13
.5
14
.0 -
14
.5
15
.0 -
15
.5
16
.0 -
16
.5
17
.0 -
17
.5
18
.0 -
18
.5
19
.0 -
19
.5
20
.0 -
20
.5
21
.0 -
21
.5
22
.0 -
22
.5
23
.0 -
23
.5
0 .0
- 0
.5
Time (0.5 hr)
Me
tha
ne
pro
du
ctio
n (
L/m
in)
LOW or -RFI
MEDIUM RFI
HIGH or +RFI
Three Cross Ranch – 2007 breeding season
Mating Grp 1 +RFI -RFI
X 123 cows
Mating Grp 2 +RFI -RFI
X 121 cows
Mating Grp 3 +RFI -RFI
X 48 cows
Morison’s Feedlot – Jun – Sep 2009 Feed Intake test, 240 feeders
20
12
0S
WK
29
SJ
B3
8S
JB
41
8S
WK
10
3S
11
SJ
B9
4S
74
8S
DC
25
S4
5D
C1
9S
DC
27
S5
2S
AL
13
9S
38
50
S1
09
S9
1S
77
S4
23
14
14
93
49
6S
14
S3
91
75
1 2 91
02
42
25
64
16
S4
03
32
51
08
S1
12
S4
20
S2
03
32
63
54
88
12
17
4S
18
06
7S
40
S1
11
51
23
S3
22
9A
L1
50
SJ
B1
01
SW
K2
0S
WK
98
SD
C2
4S
46
WK
11
4S
40
3S
JB
87
SJ
B6
8S
JB
24
S6
96
7
Bull ID
-2
-1.5
-1
-0.5
0
0.5
1
1.5
RF
I, k
g D
M/d
ay
Distribution of Residual Feed Intake (RFI) for TX BeefBooster
bulls tested from Dec 11/2006 to Mar 8/2007.
(barley silage:grain (60:40%) diet)
n=73, mean=0.00
SD= 0.506
R2 x 100 = 58.2%
9 -RFI
BULLS
9 +RFI
BULLS
7. No effect on bull fertility Wang, Ambrose, Colazo, Basarab et al., J. Anim. Sci. 2011
Traits n rp sign.
365-day SC, cm 404 0.01 NS
Front feet score 343 0.02 NS
Front leg score 274 -0.01 NS
Hind feet score 343 0.03 NS
Disposition score 343 -0.04 NS
Semen morphology 260 0.08 NS
Semen motility 260 0.14 *
Semen conc. score 260 -0.09 NS
Progeny produced (27 sires) 0.00 NS
Relationship (rp) between RFI and breeding
soundness in yearling beef bulls
No difference in culling reasons: 42.1% of +RFI & 41.5% -RFI bulls culled
3.7% reduction in DMI (0.35 kg DM/d/9.5 kg DM/d); cow 13 kg DM/d x 3.7% x $0.15/kg DM x 365 = $26/cow
-1.5 -1 -0.5 0 0.5 1
Sire phenotypic RFI, kg DM/day
-0.5
0
0.5
Average P
rogeny R
FI,
kg D
M/d
ay
y = 0.016 + 0.352x,
sire=13, R2 = 57.3%
0.352 kg DM/day x $0.30/kg DM x 150 days
= $15.84/hd
Relationship between sire phenotypic RFI and
average progeny phenotypic RFI (Three Cross Ranch)
Where r-square for growth curves was greater than 0.95 and progeny per sire is 2 or more.
Slope equal for slaughter heifers and steers.
Progeny performance Sires Sires
During finishing +RFI -RFI Sign.
Number of progeny 95 144
Progeny carcass weight, kg 366 372 NS
Progeny carcass grade fat, mm 11.0 11.3 NS
Progeny ribeye area, cm2 93.5 93.7 NS
Progeny marbling score 4.22 4.30 NS
Progeny yield grade 1.38 1.45 NS
Progeny lean meat yield, % 58.6 58.4 NS
NS, not significant, P>0.05
Effect of sire RFI on the carcass quality of their progeny
Individual Animal Feed Intake Facility, Lacombe Research Centre, AB, Canada
Cow productivity & reproductive fitness
56.6% barley straw:40.0% silage
3.4% Feedlot sup (32% CP)
ad libitum twice daily
30% straw:70% grass hay (DM basis)
9.6% CP, 8.75 MJ ME/kg DM
7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6
Age, mo
0
2 0
4 0
6 0
8 0
1 0 0
Cu
mu
lati
ve
% r
each
ing
pu
ber
ty
[-RFI] n=94
[+RFI] n=89
P = 0.03
P = 0.40
P = 0.34
P = 0.22
P = 0.29
P = 0.54
P = 0.99A.
8. No effect of RFIfat on age at puberty and pregnancy
A. Levels of significance are given for cumulative percent of heifers reaching puberty by
9, 10, 11, 12, 13, 14 and 15 mo of age. B. Levels of significance are given for cumulative
percent heifers pregnant by 2, 7, 12, 17, 22, 27, 32 and 37 d of the breeding season.
Adapted from Basarab et al. (2011).
0 1 0 2 0 3 0 4 0
Days from start of breeding season
0
2 0
4 0
6 0
8 0
1 0 0
Cu
mu
lati
ve
% p
reg
na
nt
(-RFI) n=94 (+RFI) n=96
P=0.49
P=0.76
P=0.47
P=0.68P=0.38
P=0.29
P=0.80
P=0.80
B.
0 1 0 2 0 3 0 4 0 5 0
Days from start of calving
0
2 0
4 0
6 0
8 0
1 0 0
Cu
mu
lati
ve
Per
cen
t (%
)
-RFI +RFI
9. No effect of calving pattern
RFI adj.
for fat
n= 75 n= 73
NS
NS
NS
NS
NS
Heifers exposed to breeding 98 92
Calving difficulty, % 6.7 9.2 NS
Total calf death, % 5.3 11.8
Calf death unknown, % 2.7 7.9
Weaning rate, % 71.4 71.7 NS
Birth weight, kg 36.6 36.5 NS
Pre-weaning ADG, kg/day 0.98 0.99 NS
Weaning weight, kg 251 255 NS
Heifer productivity, kg/hd/yr 186 191 NS
Heifer RFI fat
-RFI +RFI sign. Trait
Productivity traits in -RFI and +RFI first calf heifers
Basarab et al. 2011; improved early life survival 1) better uterine env. due to more available nutrients, and 2)
lower reactive oxygen species, proton leakage in mitochondria and oxidative stress at cell level.
LOW RFI cow J1042 (5 yr-old Hereford-Angus cow
in the spring of 2004; RFI adj = -2.64 kg as fed/day;
2003 weight at weaning =787 kg).
HIGH RFI cow E1245 (8 yr-old Hereford-Angus cow
in the spring of 2004; RFI adj = 2.83 kg as fed/day;
2003 weight at weaning = 755 kg).
10. No effect on pregnancy, calving or weaning rates
No effect on kg calf weaned/cow exposed to breeding (Arthur et al. 2005; Basarab et al. 2007)
Note: cow RFI was adjusted for conceptus weight
Long-term (1997 to 2006) ultrasound back fat thickness of cows that
produced -RFI and +RFI progeny
0 10 20 30 40 50 60 70 80 90 100 110 120
Months from January 1, 1997
0
2
4
6
8
10
12
14
16
18
Ult
ra
sou
nd
Ba
ck
fa
t th
ick
ne
ss,
mm
Progeny RFI <=-0.44 Progeny RFI >=0.44
W97
PC
PB
W98 PC
PB
PB
PB
PB
PB
PB
PB
PB
PC
PC
PC
PC
PCPC
PC
W99
W00
W01
W02
W03
W04
W05
W06
1997/98 1998/99 1999/00 2000/01 2001/02 2002/03 2003/04 2004/05 2005/06
1996/97
0 10 20 30 40 50 60 70 80 90 100 110 120
Months from January 1, 1997
550
600
650
700
750
800
850
Body W
eig
ht,
kg
Progeny RFI <= -0.44 Progeny RFI >= 0.44
W97
PC
W98
PC
PBPB
PB
PB
PB
PBPB
PC
PC
PC
PC
PC
PC
PC
W99W00
W01W02
W03
W04W05
W06
1997/98 1998/99 1999/00 2000/01 2001/02 2002/03 2003/04 2004/05 2005/06
PBPB1996/97
Long-term (1997-2006) body weight of cows that
produced -RFI and +RFI progeny
10 20 30 40 50 60 70
Cow age, mo
400
500
600
700
Bod
y w
eig
ht,
kg
+RFI -RFI
Relationship between RFIfat as a heifer and subsequent changes in body weight as a cow
PB1
MayPC1
Aug
PreCalf-1
Feb
PB2
May
PC2
Oct
PreCalf-2
Mar
PB3
May
PC3
Oct
begin swath grazing
at ~3.5-yr old
reduces winter feeding costs by 47%
Swath Grazing
10 20 30 40 50 60 70
Cow age, mo
400
500
600
700
Bod
y w
eig
ht,
kg
+RFI -RFI
Relationship between RFIfat as a heifer and subsequent changes in body weight as a cow
PB1
MayPC1
Aug
PreCalf-1
Feb
PB2
May
PC2
Oct
PreCalf-2
Mar
PB3
May
PC3
Oct
PreCalf-3
Mar
PB4
May
PC4
Oct
PreCalf-4
Mar
PC5
Oct
backfat, 4.5 vs. 7.4 at 59 mo
backfat, 10.0 vs. 12.0 at 68 mo
begin swath grazing
at ~3.5-yr old
Repeatability of RFI in heifers to cows
Peter Lawrence, 2012, University College Dublin, Ireland
RFI measured as a heifer
Traits High Med Low sign.
DMI, kg/day
12 mo of age 6.66a 6.07b 5.60c ***
24 mo of age 8.62a 8.12ab 7.68b *
36 mo of age 9.66 8.95 8.96 NS
RFI computed on post-weaned heifers offered grass silage ad libitum and
2 kg concentrate/hd/day, and grass silage ad libitum during 1st and 2nd parity
Feed savings:1 kg DM/cow/d x $0.15/kg DM x 365 = $55/cow/yr
Selection for low RFI-fat will:
Have no effect on growth, body size or
slaughter weight
Reduce feed intake at equal weight and ADG
Improve feed to gain ratio by 10-15%
Reduce net energy required for maintenance
Reduce methane production by 20-30%
Have no effect on carcass yield & quality grade
Little if any effect on age at puberty
No effect on calving pattern in first calf heifers
No negative effect on pregnancy, calving or weaning rate
Positive effect on body fatness/weight particularly during
stressful periods
Reduce feed costs - $0.05-0.10/hd/d feeders, $19-38 mil.
- $0.08-0.15/hd/d in cows; $54-110 mil.
Effect on feed intake on pasture??
Selection for low RFI-fat will:
Multi-trait Selection indices
Feedlot profitability Index (FPI): Increase genetic potential of market progeny for feedlot profit
(Crews et al. 2003)
FPI = 7.43 EBVRFI-fat + 37.38 EBVADG + -0.12 EBVWT365
RFI-fat =bull’s RFI adjusted for final off-test ultrasound
backfat thickness, kg DMI/day
ADG = bull’s post-weaning average daily gain, kg/day
WT365 = bull’s 365-day weight, kg
Also consider carcass grade fat thickness, ribeye area and marbling
Multi-trait Selection indices
Maternal Productivity Index (MPI): consistently wean heavy calves over a sustained herd life, while
controlling cow feed costs (Mwansa et al. 2002).
MPI = $3.00 EBVWWTd + $2.70 EBVWWTm – $0.49 EBVCOWT + $2.39 EBVSURV3
WWTd = direct weaning weight (30%)
WWTm = maternal weaning weight (26%)
COWT = cow weight (17%)
SURV3 = ability of a female to produce at least 3 calves given she
became a dam (27%)
Also consider heifer/bull RFI-fat adjusted, age at first calving, calving ease
and birth weight
Others (e.g. protein turnover, ion
pumping, protein leakage, thermoregulation,
stress (60%)
Feeding Patterns (2%)
Body composition (5%)
Heat Increment (9%)
Digestion (14%)
Activity (10%) Richardson and Herd, 2004
Herd et al., 2004
Biological Mechanisms Contributing to Variation in RFI
RFI, kg DM/day 1.25 -1.18 <0.001
Metabolic BW 89.0 93.8 0.48
ADG, kg/day 1.46 1.48 0.39
DMI, kg/day 11.62 9.62 0.01 17.2%
Fecal DM, g/kg DMI 272 234 0.24
Urine, g/kg MWT 56.3 45.5 0.25
Urine N, g/kg DMI 8.60 7.13 0.19
CH4, L/day 152.2 120.1 0.04 21.1%
CH4, % of GEI 4.28 3.19 0.04 25.5%
HIGH LOW
RFI RFI
Sign.
level Trait
Relationship of feedlot RFI with fecal DM, urine
and methane production in steers fed at 2.5x NEm.
LOW RFI: ME higher, HP lower, RE higher (kcal/kg MWT)
Feed intake tests favor later maturing heifers and bulls
-1.25 kg DM/d
individual
0.0 kg DM/d
contemporary group average
RFI h2
Estimated Breeding value A Simple Example
0.40
Bull RFI-p EBV = -1.25 kg DM/day x 0.40 = -0.5 kg DM/day
Cow RFI-p EBV = 0.00 kg DM/day X 0.40 = 0.0 kg DM/day
Expected Progeny Difference =
(-0.5 +0.0)/0.5 = -0.25 kg DM/day
Accuracy=40%
-1.5 -1 -0.5 0 0.5 1 1.5
RFI-fat, kg DM/day
0
50
100
150
200
250
300
350
Pr
od
uc
tiv
ity
, kg
we
an
ed
/ma
tin
g o
pp
or
tun
ity
Relationship between heifer post-weaning RFIfat and their
subsequent lifetime productivity
190.8 kg calf weaned/
mating opportunity
222 mating opportunities
86 heifers
191.8 kg calf weaned/
mating opportunity
224 mating opportunities
83 heifers
No difference in calf birth weight, pre-weaning ADG and weaning weight