Transcript Lean Growth Modeling

The Concept of
Lean Growth Modeling
AnS 320
Fall 2006
Priority of Nutrient Usage
IV. Fat
III. Muscle
II. Bone
I. Maintenance
What Is a Lean Growth Model?
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Mathematical model designed to attempt to
accurately quantify the daily nutrient requirements
of pigs during the grow-finish stages of production
based on inputs that effect performance
Mathematical model to identify means to improve
efficiency of lean pork production
Integration of current knowledge of genetic
potential, nutrient intake and environmental
conditions on pig growth
3
Why the Interest in Lean Growth
Modeling by the Pork Industry?
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Feed industry perspective
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Old nutritional approaches did not
adequately meet the needs of today’s
pigs
Base nutrient level recommendations
are not appropriate in all situations
Need for a structured method to
design feeding programs for specific
situations
4
Why the Interest in Lean Growth
Modeling by the Pork Industry?

Producer perspective
–
–
Efficiency of production is a key to competitiveness
Decisions on the implementation of cost-effective
management changes to optimize expression of genetic
potential for lean tissue growth

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The number of diets fed and the composition of the diet
Diet changes for different seasons
Target slaughter weight or weights
Choice of genotypes
Split-Gender feeding and management
5
What measurement encompasses all
of these variables?
Weight
health
Disease
Temperature
=
Protein
deposition
rate
Space allowance
6
Variables Required for Accurate
Lean Growth Modeling
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Daily protein (lean tissue) accretion rate
Partitioning of energy intake over
maintenance between protein and lipid
accretion (lean to fat ratio)
Daily feed intake
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Major hindrance to implementation is accurate,
economical means to estimate these
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Factors Affecting Rate of Protein
Accretion
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Genetic Type
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Major differences are:
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overall mean protein accretion rate
rate of decline after 200 lb
Related to maturity patterns
Genetic capacity sets the maximum
rate, but many other factors
contribute to the realized rate of
protein accretion
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Under “Ideal Commercial Conditions”
80% of Max can be achieved
8
Measuring On-Farm Protein
Deposition

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Using ultrasound equipment, we can
measure protein and fat deposition as a pig
grows.
Select a sub-sample of pigs and scan every
three weeks from 50 lb to market.
Based on the protein and fat accretion, we
can then back-calculate a lysine requirement
and feed intake.
9
Real-time Ultrasound
10
Measuring On-Farm Protein
Deposition
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By calculating the changes in:
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Weight
Loin muscle area
Backfat thickness
We can develop mathematical equations to
calculate daily protein and lipid accretion
11
Estimated Protein Deposition Using
Serial Ultrasound Measurements
Farm 1
Protein, g/d
140
120
Farm 2
100
80
60
50
75
100
125
150
175
200
225
250
Weight, lb
12
Lysine, %
Lysine Requirement
1.40
1.30
1.20
1.10
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
Farm 1
Farm 2
50
75
100 125 150 175 200 225 250
Weight, lb
13
Factors Affecting Rate of Protein
Accretion
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Genetic Type
Gender
Health Status and Environment
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herd health status and management level
interaction of health status x genetic type
14
Protein Accretion Rate: Genetic Type
Effects
160
Protein Accretion (g/day)
140
120
100
80
60
Line 1
Line 2
Line 3
Line 4
40
20
0
50
110
140
165
190
Live Weight (lb)
220
260
275
Factors Affecting Protein
Accretion Rate
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Gender Effects
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Gilts exceed barrows in protein accretion even
at lighter weights and the differences increase
with weight.
Basis for split-gender feeding and phase
feeding as the differences in overall rate of lean
growth and the rate of lean growth decline are
different for barrows and gilts.
16
Gender Effect on Growth Rate:
Commercial Conditions
2.5
2.4
2.3
2.2
2.1
ADG
2
(lb/day)
1.9
1.8
1.7
1.6
1.5
Barrow
Gilt
5
26
Live Weight (lb)
0
23
0
20
0
17
5
13
0
10
65
Schinckel and Delange
17
Gender Effect on Protein Accretion
Rate: Commercial Conditions
Protein Accretion (g/day)
130
120
110
100
Barrow
Gilt
90
80
70
60
5
26
0
23
0
20
0
17
0
13
0
10
65
Schinckel and Delange Live Weight (lb)
18
Modeled Impact of Gender and
Farm on ADG
2
ADG (lb)
1.75
1.5
Barrow-Farm A
Barrow-Farm B
Gilt-Farm A
Gilt-Farm B
1.25
1
50
75
Tokach, et. al, 1997
100
125
150
175
200
225
250
Live Weight (lb)
19
Modeled Protein Accretion:
Barrows and Gilts
Protein Accretion (g/day)
135
115
Barrow-Farm A
Barrow-Farm B
Gilt-Farm A
Gilt-Farm B
95
75
50
75
Tokach, et. al, 1997
100
125
150
175
200
225
250
Live Weight (lb)
20
Modeled Percent Lysine Needed
Based on Protein and Lipid Accretion
Percent Lysine
18
16
14
Barrow-Farm A
Barrow-Farm B
Gilt-Farm A
Gilt-Farm B
12
10
50
75
100
Tokach, et. al, 1997
125
150
175
200
225
250
Live Weight (lb)
21
Health and Management Effects on
Protein Accretion Rate
Protein Accretion (g/day)
150
130
110
90
Ideal
Above Average
Average
Below Average
70
50
Live Weight (lb)
310
265
220
180
130
85
45
Schinckel, 1996
22
Commercial vs Optimal
Environmental Conditions
Environment
Commercial Optimal
Daily gain, lb/day
1.61
2.28
Days to 260 lbs
192
160
Daily fat free lean gain, g/day
240
342
Daily Fat Gain, g/day
240
353
Daily feed intake
5.39
6.6
Feed/gain
3.29
2.85
Feed/lean gain
10.39
9.30
Backfat, in
.98
1.08
Schinckel, 1997
% of comm.
142
83
142
148
122
87
90
12%
23
Commercial vs Optimal
Environmental Conditions
Average Daily Gain (lb/day)
2.5
2.4
2.3
2.2
2.1
Optimal
Commercial
2
1.9
1.8
1.7
1.6
1.5
5
26
Live Weight lb)
0
23
0
20
5
16
0
13
0
10
65
Schinckel, 1997
24
Commercial vs Optimal
Environmental Conditions
1
Lean Gain g/day
0.9
0.8
0.7
Commercial
Optimal
0.6
0.5
0.4
0.3
5
26
Live Weight (lb)
0
23
0
20
5
16
0
13
0
10
65
Schinckel, 1997
25
Commercial vs Optimal
Environmental Conditions
Feed Intake (lb/day)
9
8
7
6
5
Optimal
Commercial
4
3
Schinckel, 1997
65
100
130
165
200
Live Weight (lb)
230
265
26
Partitioning of energy intake over
maintenance between protein and lipid
accretion
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Genetic Type
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High lean growth lines require less energy to
achieve the same lean growth rate as moderate
genetic types.
However, high lean growth lines are more
affected by situations where energy intake is
limited and respond with larger absolute and
percentage drops in lean growth rate when
compared to other genotypes
Schinckel and Delange
27
Importance of Feed Intake
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Voluntary feed intake is a driven by
the pig’s requirements for nutrients
Feed intake is reduced as a function
of constraints imposed on the
animal
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Diet characteristics
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Environment
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bulk density, fiber content, nutrient content,
etc.)
thermal, social, physical, disease
Pig’s physical capacity to ingest feed
Schinckel and Delange
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Feeding Paylean

Paylean® Technical Manual
 “Swine feed premix containing
ractopamine which directs nutrients to
increase the amount of quality meat in high
value cuts and improves production
efficiency”
 Beta-Andrenergic Agonist – Mode of action
is the stimulation of beta-receptors (Beta-1
type) in the cell
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Paylean Effects on the
Pig
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Production Effects (Asset Utilization)
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Increased Average Daily Gain
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Improved Feed Efficiency
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Reduced feed cost/lb of gain (lean)
Decreased Carcass Fat
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Potential to increase throughput if pigs available to fill barns
Potential to market at heavier weights (> pounds/space/year)
Reduces fat deposition
Increased Carcass Muscle (loin, ham, etc)
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Increases muscle development
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Paylean Effects on the
Pig
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Higher Percent Lean (less fat, more muscle)
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Opportunity to obtain higher lean premium
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Higher Dressing Percentage
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Depends on packer merit system
Heavier carcass at a standard weight
Potential to increase frequency of Slow and
Downer Pigs
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Heavier muscled pigs more susceptible to stress
Physiologically more muscle may put stress on tendons,
ligaments, etc.
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Paylean® Effects - ADG
Trait
ADG:Ent-Mkt
ADG:St-Mkt
ADG:St-PAY
ADG:Wk1
ADG:Wk1-2
ADG:Wk1-3
ADG:Wk1-4
Days/240
Control
1.53d
1.93b
1.86
2.42b
2.09b
2.13b
2.06b
170.6
Paylean
1.57c
1.99a
1.86
2.86a
2.48a
2.43a
2.27a
167.8
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Paylean® Effects - Feed Efficiency
3
2.5
2
b
b
b
b
a
a
a
a
1.5
Control
Paylean
1
0.5
0
WK 1
WK 1-2
WK 1-3
WK 1-4
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Influence of Paylean Level on
Margin $/pig greater than controls
$4
$0.67
$3
$0.38
$0.54
Lean
Weight
$2
$1
$2.17
$2.14
4.5
6.8
$2.53
$0
Paylean, g/ton
9.0
Main et al., 2001
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Nutrients of Primary Concern in
Waste Management
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Nitrogen
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Amino Acids that comprise
the Proteins required for life
Phosphorus
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Mineral required for bone
development, body function,
health, etc.
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Environmental Concerns for Nitrogen
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Volatilization of Nitrogen to Ammonia (NH3)
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Returns to land or water via rainfall, dry precipitation,
or direct absorption
Potential for significant odor generation
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Community/neighbor relations can be strained
Nutrient distribution
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Meeting agronomic needs without the adverse effects
of over-application
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Environmental Issues for
Phosphorus
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Direct and indirect contamination of water
resources
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Surface and sub-surface waters
Nutrient distribution
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Meeting agronomic needs without the adverse
effects of over-application
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Nitrogen and Phosphorus Intake,
Excretion and Retention in Swine
Intake
(lbs)
Nursery
(20 – 50 lb)
N
P
Excretion Retention
(lbs)
(%)
2.07
0.46
1.23
0.29
40
37
Grow-Finish N
(50 – 250 lb) P
13.93
2.69
9.35
1.81
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33
Breeding
(19.6 p/s/y)
61.78
14.46
49.43
11.95
20
17
N
P
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Nutritional Approaches
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High quality protein
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Balance of amino acids in protein sources
defines quality
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Soybean meal and fish meal: High Quality
Peanut meal and cottonseed meal: Low Quality
Excess nitrogen excretion occurs when using
too much low quality protein in feed
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Most limiting AA can define the amount of protein
included in a diet thus feeding protein to meet the
most limiting AA can increase Nitrogen excretion
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Nutritional Approaches
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Dietary formulation
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Formulate and balance diets to meet the Amino Acid
requirement, rather than the Crude Protein requirement, for the
optimal lean growth rate of the genetic type of pigs you raise
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Crystalline lysine and methionine are generally cost effective
Synthetic threonine, valine, isoleucine,and tryptophan are available, but
may not be cost effective
Lysine substituted for soybean meal reduces CP by ~2% in the
diet and can result in a 20 to 25% reduction in N excretion
(Pierce et al, 1994)
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On-Farm Strategies to Improve P
Utilization and Reduce P Excretion
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Phosphorus excretion is Influenced by:
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Amount of phosphorus consumed
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Excess fortification of P in diets was common in the past, but
not wise and unjustified today
Form or bioavailability of the phosphorus in the diet
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Phosphorus in the Phytate or phytic acid form is largely
unavailable to swine because swine lack the intestinal
enzyme phytase to break down the phytate
Large differences in bioavailability of phosphorus in common
feedstuffs
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Nutritional Approaches to Reducing
Phosphorus Excretion
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Poultry and swine lack a critical enzyme (phytase)
which releases phosphorus from phytic acid and
makes it available for utilization
Approximately 2/3 of plant phosphorus is bound to
phytic acid and is unavailable for utilization by both
swine and poultry
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Thus, inorganic P sources (Di-calcium phosphate, defluorinated phosphate) are added to diets
42
New Approaches to Phosphorus
Utilization and Management

Synthetic phytase enzyme added to the
feed
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Phytase releases 20 to 40% of the bound P in
typical dietary ingredients
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The addition of phytase combined with a reduction
from 0.6% P to 0.5% P (inorganic) in the pig diet
results in a 20 to 50% reduction in Phosphorus
excretion

In addition, Ca is more readily absorbed resulting in
reduced Ca excretion
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Low Phytate Corn and/or Low Phytate
Soybean Meal
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Use of Low Phytate Corn (HAP corn)
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Genetically enhanced corn varieties are now available
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Lpa1 mutant gene in corn inhibits phytate synthesis
Reduction by ~50% the amount of P in the phytate form
Phosphorus is 3 to 4 time more bioavailable compared with
normal corn (Cromwell 1998, Douglas et al. 2000)
Up to 40% reduction in phosphorus excretion when fed to
swine (Pierce & Cromwell 1999, Spencer et al., 2000)
Further reduction in Phosphorus excretion when phytase is
used in conjunction with low-phytate corn
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Low Phytate Corn and/or Low
Phytate Soybean Meal
Normal Corn Low-Phytate
Total P
0.25%
0.26%
Phytate-P
0.21%
0.08%
Non-Phy P
0.05%
0.18%
(Li et al., 2000)
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Low Phytate Corn and/or Low Phytate
Soybean Meal
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Use of low phytate soybeans
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Genetically enhanced soybeans
recently developed
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Response similar to those
observed when feeding lowphytate corn
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More available form of
phosphorus
Reduction in phosphorus
excretion
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Feeding Management
Considerations
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Feeding for “Optimal” vs Maximum
Performance
Incremental change in
performance is reduced as
nutrient levels increase
“Law of Diminishing Returns”

Added cost of diet and nutrient
level excretion potential dictates
formulation for “optimal” nutrient
levels
47
Feeding Management
“Multiple Phase” Nutrition Program designed to meet genetic
capacity, health and facilities of the pig
18
Minimize overfeeding
of essential nutrients
Crude Protein %
17
16
15
14
13
CP and Nutrient Levels
changed frequently to
closely match pig needs
12
50
Live Weight
250
48
Effect of Phase Feeding
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Inefficiencies occur when the diet provides more
nutrients than the animal needs
More phases = less waste and cheaper diets

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But also = more hassle
Compromise between number of phases and benefits
achievable
In-line mixers/liquid feeding systems allow for
continuously changing the diet composition without
increasing hassle
49
Impact of PhaseFeeding on Nitrogen
Excretion
Dietary Crude Protein %
Nitrogen
output/day lb
% of
two - feeds
Single Feed
17%
Two-Feeds
17 & 15%
Three Feeds
17 – 15- 13%
0.070
0.064
0.059
110
100
92
50
Nutritional Approaches

Split-sex feeding (gilts vs barrows)


Sex differences may dictate feed
formulation
Gilts are generally higher in lean, have
lower feed intake, and better feed
efficiency



Require higher levels of CP and more
energy dense diets than barrows at a given
weight
Complements the goals of phase feeding
NOTE: Gender differences today are less
in leaner genetic types, thus some
producers have abandoned this concept
51
On-Farm Strategies to Improve N
Utilization and Reduce N Excretion

Focus on Feed Efficiency

Monitor Diet Quality and Form

Proper grind (700 microns) enhances nutrient availability and
nitrogen utilization


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Ohio Study from the late 90’s showed a wide range in particle size
from both on-farm and feed mill processed grains, with most samples
too coarse
Pelleted diets improve feed efficiency compared with meal diets
(pelleting costs may be an issue)
High-quality feedstuffs improve conversion efficiency
52
Recommended Feeder Adjustments
after Weaning
Initial feeder adjustment
2 to 3 weeks into turn
Final feeder adjustment
Courtesy Steve Dritz, KSU
53
Nutritional Approaches

Feed Additives

Use of a Beta-Agonist (Paylean®) to improve
feed:lean conversion efficiency

Reduction in nitrogen excretion


Reduced total volume of manure


Increased efficiency of nitrogen utilization through an
improvement in lean tissue growth, reduction in fat
deposition and or increase in fat degradation
Feed intake is reduced and feed efficiency improved
Improved P retention
54
Production Management

Facilities and Herd Health


Proper ventilation rates and
temperature control
enhance productivity and
efficiency
All-in, All-out production flow
improves pig health and
production efficiency
55
Summary
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Enhance nutrient (N and P) availability, utilization
efficiency, and reduce excretion
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Phase-feeding – Easy, low cost
Crystalline Amino Acids – Cost effectiveness?
Micron size – Fast, easy
Feeder management – Easy
Feed additives – Cost effectiveness?
HAP-corn/soy – Agronomic production cost, yield, etc. must be
considered


Today a question of AVAILABILITY
Microbial phytase – Appears quite effective

Used extensively
56