Effect of rate and extent

of starch digestion on

broiler and laying hen

performance

E. Herwig, R. K. Savary, K. Schwean-Lardner and H. L. Classen

University of Saskatchewan, Saskatoon, SK, Canada

Background

Starch is the most important energy source in

poultry

Factors affecting rate and extent

of starch digestion include:

Size of the granule

Degree of crystallinity

Amylose:amylopectin ratio

Encapsulation(Parada & Aguilera, 2011)

http://polysac3db.cermav.cnrs.fr/

Starch classification

Jejunum

Ileum

RDS SDS RS

(Englyst & Hudson, 1996)

www.roysfarm.com

Energy source for ileum

Fermentation

Nutrient sensing

Post-absorptive effects

RDS: Rapidly digested starch

SDS: Slowly digested starch

RS: Resistant Starch

Energy source for ileum

Normal SDS

Starch

Theprojectopenwindow.com

L-Glutamate

L-Glutamate

L-glu oxidation = Energy

L-Glutamate

L-Glutamate

L-glu + starch oxidation = Energy

Fermentation

Nocek & Russell, 1988; Sciencenews.org

Protein

Ammonia

Starch, fibre & sugar

Volatile Fatty Acids

Microbial Fermentation

Nutrient sensing

E-dmj.org; youtube

Starch

Ileum

Nutrients

Inhibition

Inhibition

Brain

Intestine

Kidney Muscle

Adipose

tissue

Meal

Glucose

Engelking, 2011

cv

c

v

Brain

Intestine

Kidney Muscle

Adipose

tissue

Glucose

Glycemic index

In Vitro

SDS

RDS

In Vivo(Seal et al., 2003)

Plasma glucose

Plasma insulin

Poultry – In vitro starch digestion (%)

(Weurding et al., 2003)

0

20

40

60

80

100

0 1 2 3 4 5 6TIME (HR)

Tapioca-Corn Pea-Corn

RDS

SDS

Feed:Gain (g/g)

1.591.57

1.541.53

1.52

1.63

1.60

1.571.57

1.54

8.50 9.13 9.75 10.38 11.00Digestible lysine content (g/Kg)

Pea-Corn Tapioca-Corn

(Weurding et al., 2003)

Objective

To determine the effects of starch

digestibility rate and extent on the

performance of broiler chickens and laying

hens using semi purified starch sources

Slowly or poorly digestive starch will result in

more feed efficient broiler and egg

production

Hypothesis

Broiler Production Trial

Materials – Starch sources

Starch (%) Moisture (%) CP (%) Fibre (%) Fat (%) Ash (%)

Wheat 92.50 7.00 0.30 0.10 0.06 0.00

Pea 80.00 5.78 6.31 1.71 0.89 0.95

Starter diet 0 SDS 20 SDS 40 SDS 60 SDS 80 SDS 100 SDS

Wheat Starch 51.74 41.39 31.04 20.69 7.24 0.00

Pea Starch 0.00 11.87 23.74 35.61 51.04 59.35

Pea Protein 7.61 6.09 4.57 3.05 1.07 0.00

Total starch 59.35 59.35 59.35 59.35 59.35 59.35

Wheat Starch + Pea Protein = Pea Starch

Methods

4500 Ross 308 broiler chickens

6 rooms of 12 floor pens/room (32 kg/m2)

RCBD: 6 diets x 2 gender blocked by room

Duration: 31 days

0 20 40 60 80 100 Total

Males 6 6 6 6 6 6 36

Females 6 6 6 6 6 6 36

Total 12 12 12 12 12 12 72

MethodsData collection

Dietary analysis

Body weight

Feed intake

Mortality

Meat yield

SAS 9.3

Mixed model

Regression analysis

Significance level P < 0.05

Results – In vitro digestibility (%)

30

40

50

60

70

80

90

100

15 30 45 60 90 120 180 240

Time (min)

020406080

100

Body weight gain (kg) 0-31 d

Linear regression P = 0.0016

(Quadratic response approached

significance P = 0.0904)

1.901.93

1.911.87

1.85

1.77

0 20 40 60 80 100

Ross 308 = 1.73

Feed Intake (Kg) 0-31 d

2.982.93 2.92 2.89 2.85

2.91

2.61 2.64 2.672.62 2.63

2.67

0 20 40 60 80 100

Males Females

M: Linear regression P = 0.0054 (Quad. P = 0.0555)

F: No regression

Male Ross 308 = 2.74

Female Ross 308 = 2.47

Feed efficiency (G:Fm) 0-31 d

Quadratic regression P = 0.0001

0.690.70

0.690.68 0.68

0.64

0 20 40 60 80 100

Ross 308 = 0.68

Meat Yield

2.062

1.9852.013

1.980

1.8991.879

0 20 40 60 80 100

Meat Yield – Live Weight

Linear regression P = 0.0046

Meat Yield – Carcass weight(% of Live weight)

Quadratic regression approaches signific. P= 0.0814

69.9

71.5 71.5

70.870.6 70.6

0 20 40 60 80 100

Meat Yield – Breast meat(% of Live weight)

Linear regression P = 0.0349

19.3

20.2 20.3

20.0

20.4 20.3

0 20 40 60 80 100

Meat Yield – Breast skin(% of Live weight)

Linear regression P = 0.0096

3.12 3.182.89 2.91 2.95

2.80

0 20 40 60 80 100

Meat Yield – Thigh meat (% of Live weight)

Quadratic regression P = 0.0234

4.3

4.4

4.5 4.5

4.4 4.4

0 20 40 60 80 100

4.7 4.7

4.8 4.8 4.8

4.7

0 20 40 60 80 100

Meat Yield – Whole drum (% of Live weight)

Quadratic regression P = 0.0247

Meat Yield – Drum skin (% of Live weight)

Linear regression P = 0.0022

0.48 0.50 0.490.46 0.44 0.43

0 20 40 60 80 100

Meat Yield – Abdominal fat(% of Live weight)

0.8090.746

0.6070.660

0.5850.650

0 20 40 60 80 100

Linear regression P = 0.0081

(Quad. Resp. approached significance P = 0.0987)

Conclusion

Low levels of SDS improved broiler

performance

Inclusion of SDS increased breast, thigh

meat and whole drum yield

Skin weight decreased as SDS inclusion

increased

Apparent shift in the allocation of resources from fat to muscle

Broilers vs. laying hens

Age

Development of digestive tract

Microbial community

Different feeding patterns

Laying Hen

Production

Trial

Materials & Methods

720 Lohmann LSL hens 26 weeks old

Conventional cages (503 cm2/bird)

Dietary treatments:

0, 20, 40, 60, 80 & 100 SDS

Duration of the experiment: 20 weeks

Material & MethodsData collection

Dietary analysis

Feed intake

Daily egg production

Egg quality

Body weight

SAS 9.3

Mixed model

Regression analysis

Significance level P < 0.05

1.681.66

1.71

1.74

1.70

1.63

0 20 40 60 80 100

Body Weight (Kg)

Quadratic regression P = 0.0021

Lohmann LSL = 1.60

Lohmann LSL = 1.73

102.3

103.9104.9

105.6

108.9 109.4

0 20 40 60 80 100

Feed intake (g/hen per day)

Linear regression P < 0.0001

Lohmann LSL = 103.5

93.393.76

95.52 95.496.03

94.95

0 20 40 60 80 100

Total hen day production (%)

Lohmann LSL = 95.83

Linear regression P = 0.0102

(Quad. Reg. approached significance P = 0.0524)

59.49 59.46

59.8859.73

59.64 59.63

0 20 40 60 80 100

Egg weight (g)

Lohmann LSL = 60.70

1.0835

1.0849

1.08611.0864

1.0858

1.0842

0 20 40 60 80 100

Specific gravity

Quadratic regression P = 0.0004

0.07

0.110.12

0.08

0.10

0.12

0 20 40 60 80 100

Egg cracks (%)

1515.3

1535.11525.5

1564.81571.8

1541.5

0 20 40 60 80 100

Egg mass (g/hen housed)

Linear regression P = 0.0334

1.85

1.87

1.84

1.86

1.91

1.94

0 20 40 60 80 100

Feed efficiency (Feed g/egg mass)

Quadratic regression P = 0.0015

Conclusions

Intermediate levels of SDS improved egg

production

Quadratic response for FCR mostly related to

increased feed intake at high SDS levels

No effects of SDS on egg weight or quality

Take home message

Incorporation of low levels of starch

sources in chicken diets with lower

digestion rates and extent of digestion

may result in better chicken performance

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