Transcript Using Ultrasound for Nutrition Genetics and Management

Applying feed intake monitoring
systems into producer testing
programs
Dr. Daryl R. Strohbehn
Extension Beef
Specialist
Iowa Beef Center @ ISU
Why Feed Efficiency?

With everything else equal or even less wouldn’t
you rather have a more feed efficient sire?
Why Feed Efficiency?

Feed cost represents 60% of
the total cost in finishing cattle.
(Fox @ 2002 BIF)



Feed cost represents 63% of
total financial cost to run a
beef cow. (Strohbehn, IA SPA results 2000-04)
A 10% improvement in feed
efficiency can improve feedlot
profits 43%. (Fox, et.al. 2001)
65-75% of total dietary energy
cost in breeding cows is
required for maintenance. (Ferrell
& Jenkins 1985; NRC 1996)

A 5% improvement in feed
efficiency has an economic
impact 4 times greater than a
5% improvement in ADG. (Gibb &
McAllister 1999)
Why Feed Efficiency?
Environmental friendly
cattle
 Selection for improved
feed efficiency will:

– Lower methane
emissions by 9 to 12%
(Okine, et.al. 2001)
– Reduce manure N, P and
K production by 15-17%
(Arthur, et.al. 2002)
Why Feed Efficiency?
It’s a heritable trait.
Trait
Heritability
Feed conversion (f/g)
.36
Feed efficiency (g/f)
.42
Feed intake
.41
Koots, et.al. 1994
Efficiency Traits – Let’s get our definitions straight
Feed Conversion =
Feed Intake / Animal Gain
Example - 4:1 or 8:1 (lbs of dry matter / lb gain)
Feed Efficiency =
Animal Gain / Feed Intake
Examples: .25 lbs gained / lb feed or .125 lbs gain / lb feed
(usually expressed in units of 100% dry matter)
Later on I will talk about RFI, NFI and NFE.
I remember when….1960-70’s
 Individual
fed bulls in separate pens
– Example: Wye Plantation in Queenstown,
Maryland
 Daily
hand kept written records
 Very, very high labor
 No animal peck order, thus no impact
from competition
Technology Advancements
<-PinPointer 4000
system
Technology Advancements
Calan Electronic
Feed Gates 
- Each animal has
its own space and
daily written
records
System at Circle A Angus, MO
GrowSafe
System, Canada
Feed Conversion testing with
on the farm/ranch systems

Don’t take this job lightly
– It’s like milking dairy cows, methodical daily
duties.
Requires attention to feed and
management details, regardless of
intake monitoring system utilized.
 Requires meticulous record keeping,
both with feed intake and weight gains.

Record analysis assistance
may be needed.



Feed conversion is just
not feed intake divided by
gain.
Most tests are equal time
on feed, thus bull weights
while on test vary a great
deal.
BIF method: account for
differences in average bull
weights during test.
Range in off test weight: 974 - 1541
BIF Methodology

Adjusted Feed Conversion uses metabolic
weights.
– ( W.75 / Wi.75 ) x ( Feed / Gain )
– W is the mid test weight; the average of the initial
weight and final weight.
– This method adjusts feed/gain of heavier than
average bulls downward and lighter than average
bulls upward.
Question ???

Two bulls have the same Feed Conversion and 3.5 lb ADGs on
120 day test.
– 6.5 lbs feed to 1.0 lb gain
– Bull A and B have off test weights of 1300 and 1200, respectively.
– Are they the same for Feed Conversion?

NO !
– After adjusting for differences in body weight
– Bull A’s average test weight was 1090 lbs, Bull B’s average test weight
was 990 lbs
» Bull A Adjusted FC=6.27
» Bull B Adjusted FC=6.74
Beef Improvement
Federation Guidelines
Duane Warden
Warden’s Ironwood Angus
Council Bluffs, IA
24 years of feed
efficiency testing
using PinPointer
system
Warden’s Adjusted Feed Conversion 1995-2004
y = -0.2021x + 7.6846
R2 = 0.3845
8
7.5
7
6.5
6
5.5
5
4.5
4
1995
1997
1999
2000
2001
2002
2003
2004
Warden’s Adjusted Feed Conversion 1995-2004
New
Level
bull
701
bull8
0350
bull
8 + 7.6846
-0.2021x
y 4= Point
bull2
R = 0.3845
7.5
3303
bull
7
6.5
4333
bull
6
5.5
5
4.5
4
1995
1997
1999
2000
2001
2002
2003
Influence sires – Past and Present
2004
Warden’s Adjusted Feed Conversion 1995-2004
New
Level
bull
701
bull8
0350
bull
8 + 7.6846
-0.2021x
y 4= Point
bull2
R = 0.3845
7.5
3303
bull
7
4333
bull
6.5
6
5.5
5
Warden Smarts
4.5
Sire
4
701
1995
1997
1999
2000
2001
2002 New 2003
Level
Adj Feed Conversion
5.84
2004 5.02
0350
5.18
4 Point 8
4.82
3303
5.21
4333
5.18
Warden’s Adjusted Feed Conversion 1995-2004
New
Level
bull
701
bull8
0350
bull
8 + 7.6846
-0.2021x
y 4= Point
bull2
R = 0.3845
7.5
3303
bull
7
4333
bull
6.5
6
5.5
Warden Smarts
5
Sire
4.5 RFI
701
-.70
New Level
4
-2.20
1995
0350
-1.33
4 Point 8
-2.61
3303
-1.06
4333
-2.50
1997
1999
2000
2001
2002
2003
2004
Over 40 Years Ago


Dr. Robert Koch, U of
Nebraska research and
reported on a new system
that adjusted feed intakes for
body weight and growth.
Splits feed intake into two
portions
– 1. feed intake for a given level
of growth & size
– 2. a residual portion
Data from:
-Lincoln, NE
-Fort Robinson, NE
-Fort Reno, OK
Breeds:
Angus
Hereford
Shorthorn
Thus was born RFI
(Residual Feed Intake)

RFI is also known as:
– NFI: Net Feed Intake
– NFE: Net Feed Efficiency
RFI is the difference between a bull’s
actual feed intake and its expected feed
intake based on its size and growth.
 RFI = actual DMI – expected DMI
 Heritability estimates 29% to 46%

RFI
(Residual Feed Intake)
Used to identify animals that are either
+ or – from their expected ME intake.
 -NFE = high efficiency
 +NFE = low efficiency

Individual
Bull Expected
DMI
Individual
bull DMI
ADG
-NFE
Wt.
Studies indicate RFI is an
independent trait
Warden data
no correlation
between Off
Test Weight and
RFI
6.00
r = -.02
4.00
2.00
RFI

Relationship between RFI and Off Test Weight
Warden Data: 1987-2005 (n=316 hd.)
0.00
-2.00900
1100
1300
-4.00
-6.00
Off Test Weight
1500
Studies indicate RFI is an
independent trait
Relationship between RFI and ADG
Warden Data: 1987-2005 (n=316 hd.)
5.50
Warden data no
correlation
between ADG and
RFI.
r = -.01
5.00
4.50
ADG

4.00
3.50
3.00
-6.00
-4.00
2.50
-2.00
0.00
RFI
2.00
4.00
6.00
Studies indicate RFI is an independent trait,
but related to Adjusted Feed Conversion
Warden data .46
Relationship between RFI and Adjusted
Feed Conversion
correlation
between Adjusted
Feed Conversion
and RFI
10
r = .46
9
8
AFE

7
6
5
4
-5.00
-3.00
-1.00
NFI
RFI
1.00
3.00
5.00
Studies indicate RFI is an independent
trait, but related to Dry Matter Intake
Warden data
.55 correlation
between Dry
Matter Intake and
RFI.
34.00
r = .55
32.00
30.00
28.00
DMI

Relationship between RFI and Dry
Matter Intake
26.00
24.00
22.00
20.00
-5.00
-3.00
18.00
-1.00
1.00
RFI
3.00
5.00
Other relationships were
evaluated….

A significant correlation
between RFI and ultrasound
fat cover existed (.17)
– Means fatter bulls were less
efficient

No significant relationships
existed between RFI and
other performance
parameters.
– EPDs (BW, WW, YW, Milk) and
ultrasound REA
Dilemma with calculating RFI




Requires doing a regression
analysis of the data to develop an
equation called Expected Dry
Matter Intake.
Expected Dry Matter Intake is then
used against Actual Dry Matter
Intake to develop the RFI.
Not many producers have the
expertise and knowledge of
statistics to do this exercise.
Going to require serious expertise
involvement either from Extension
Service or Breed Association.
Warden-Beedle
information
gathering system
using off the shelf
electronic
components.
Joint project with
the Iowa Beef
Center, Miraco,
ID-ology, and
Rice Lake Scales
Our Future…..Let’s Hope.
A view from Australia on the possibilities
Angus NFI Percentile