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Current Advances in Broiler Breeder Modeling Research: a North American

Perspective

Martin J. Zuidhof1

R. A. Renema, and A. Pishnamazi

AMEVEA

Bogotá, Colombia

April 18-19, 2012 1 martin.zuidhof@ualberta.ca

1957 broiler 1977 broiler 2005 broiler

Why are Broiler Breeders Difficult to Manage?

The Nutritionist’s Goal• Match nutrient supply to nutrient requirements

The Organism’s Goal• To feel good and be productive

Feel good = f(eat, not eat…)Feel good = f(health, fitness, environment, luxury,

scarcity,…)

‘Properly’ fedUnderfed Overfed

Breeder:Broiler BW ratio* from 1979 to 2005

Renema et al. 2007. WPSJ 63:457-472.*6 wk of age

Uniformity Issue: Competing for a limited resource

Photo courtesy Philippe Dufour, Cobb-VantressBroiler breeder feeding time - Brazil

Uniformity at PhotostimulationReady… Set… GO!

Experimental Design

9

Treatment Diet Form ME (kcal/kg) CP (%) Frequency

Control Standard Mash 2,865 15.0 Daily

Fiber Dilute 25% Oat Hulls Mash 2,200 11.4 Daily

Scatter Standard Pellet 2,865 15.0 Daily

Skip-a-Day Standard Mash 2,865 15.0 Alternate Days

Sorted Standard Mash 2,865 15.0 Daily

10

Source Probability

Treatment <0.0001Age 0.0049Tmt x Age <0.0001

Sorting

Scatter

Sorting and Scatter Feeding Increased Uniformity

b

c

a

Summary – Uniformity Trial

• Sorting was best for uniformity– Practical consideration: help the smallest group by

segregating and giving extra feed

• Scatter feeding and skip-a-day feeding also improved flock uniformity at photostimulation

• Skip-a-day feeding – increased fat stores– reduced breast muscle weight and average egg weight

presumably due to metabolic inefficiencies

11

Feed Management

Composition / Formulation• Are current recommendations for protein levels too

high?

Current researchComposition restriction: A new paradigm in broiler breeder feeding

Feed Management

Feed Allocation• Change feed allocations gradually

– Consider the bird’s metabolism(Requirements change gradually)

– How are nutrient requirements changing?• Goal: Match nutrient supply to nutrient requirements

13

Don’t let the bird’s metabolism know that you’ve changed the feed allocation

-- Frank Robinson

Feed Allocation Principles

• Use BW gain as an indicator of metabolic status• Weigh frequently• Take the weather into consideration

RECENT RESEARCH

Manipulating Reproductive Potential: Growth Profile and Photostimulation Age

Experimental Design

• 3 commercial strains• 4 body weight targets• 2 photostimulation ages

– 18 wk– 22 wk

Growth Curve Targets

STANDARD: • Mean target BW profile

Growth Curve Targets

LOW:• 12 wk BW = 75% of STANDARD • Rapid rate of gain to 32 wk

Growth Curve Targets

MODERATE: • 12 wk BW = 150% of

STANDARD • Lower rate of gain to 32 wk

Growth Curve Targets

HIGH: • 12 wk BW = 200% of STANDARD • Minimal rate of gain to 32 wk

Age at First Egg

P-values: Strain=0.29 Feed=0.0047 PS age<0.0001

c bcb

a

Total Egg Production*

*to 58 wk of age

Photostimulation: Early = More Eggs

Photostimulation: Later = More Settable Eggs

So What?

• We may have more flexibility than we sometimes think when manipulating growth curves

When broiler breeders start to lay, they are highly motivated to repartition nutrients away from growth, and toward egg production.

RECENT MODELING RESEARCH

Effect of environmental temperature on maintenance energy requirements of broiler breeders

Core Body Temperature Dynamics

1

Feed Allocation Principles

• Use BW gain as an indicator of metabolic status• Weigh frequently• Take the weather into consideration

Pullets: Nutrient Requirement Model

• Account for – Body weight (W)– Temperature (T)– Gain (G)– Age (A)

MEI = A(W0.67) - 0.6107(W0.67)(Te - 21) + 0.9397G

“Maintenance Energy” Model

Mai

nten

ance

Ene

rgy

Requ

irem

ent (

kcal

/kg^

0.67

)

0

20

40

60

80

100

120

140

160

180

200

Age (d)

0 14 28 42 56 70 84 98 112 126 140

Age related effects (age=x)

MEm = 275.8 - 8.4941x + 0.1778x2 - 0.0016x3 + 5.09E-06x4

Why?

Comparing Results

Partitioning of 55 g of Feed*(2,750 kcal/kg)

*1.3 kg pullet

Gain per 55 g of Feed (2,750 kcal/kg)

*1.3 kg pullet *assuming requirement for gain of 0.928 kcal/g

Hens: Nutrient Requirement Model

• Account for – Body weight (W)– Environmental temperature effect on maintenance (W x T)

• Linear• Quadratic

– Gain (G)– Egg production (E)

MEI = 213.5W0.68 - 5.22W0.68(Te) + 0.11W0.68(Te2) + 0.41G +1.12E

maintenance Egg

Linear nonlinear

Effect of Temperature on maintenance Gain

Nonlinear Effect of T on ME Requirement

Predicted daily ME intake for a 3 kg bird gaining 10 g/d, producing 50 g of egg mass per day, on average

Growth (30 g/d difference)

Growth

Decreasing Post-peak Feed Allocations

• Keep birds growing on target• Birds in a positive energy balance will prioritize

nutrients toward egg production

39

Match nutrient supply to nutrient requirements

Feed allocation: nutrient requirements change slowly…Make feed increases as small and as frequent as possible

Use BW GAIN for feed allocation decisions

Principles of Breeder Management

Utilizar la GANANCIA DE PESO de las decisiones de asignacion de alimentacion

Stimulate sexual maturity by changing daylength (not feed)

Support the necessary body weight gain needed with feed

EGGS WILL FOLLOW – they are a hen’s priority

Principles of Breeder Management

Don’t let the bird’s metabolism know that you have changed the

feed allocation

Principles of Breeder Management

Don’t forget……

you are managing something you can’t see!

THE FUTUREPrecision management of individual broiler breeders

Managing Individual Hens

• Providing the right amount of feed to the right bird at the right time BW

Under target

Small meal

Target or higher

Eject from station

Breeder Management Top 10

1. Know the actual weight of your birds2. Weigh the birds at the same time each day3. Flock uniformity is very, very important4. Avoid high nutrient density diets5. Make sure pullets are at the minimum threshold

BW at lighting6. Don’t make fast increases in feed intake coming into

production

Robinson, 1996

Breeder Management Top 10

7. Know what you are doing in managing post-peak feed withdrawal

8. Keep an open mind – birds are changing every year (what worked the last flock may not work this year)

9. Don’t put your flock on ‘AUTO-PILOT’10. Stay positive person and keep learning

11. Manage birds according to body weight gain instead of BW

Adapted, Robinson, 1996

How the Benefit Will Be Gained

• Stable metabolism• Efficiency• Flock uniformity

– Egg production– Fertility

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