Bone Zn [mg / kg DM]

Bioavailability of zinc sources in

piglets and broilers:

a meta-analysis a meta-analysis

EAAP, Heraklion, Session 11, 23.08.2010

Schlegel P., Sauvant D. and Jondreville C.

Introduction

ZINC (Zn)

o Heavy metal, polluant toxic for plants and microorganisms

o Non renewable ressource

o Essential nutrient in pigs and poultry

Zn requirement is usually not met without dietary Zn supplementation

For an efficient and sustainable use of Zn in monogastric nutrition, two main strategies are recommended:

o Dietary Zn « safety margins »

o Dietary Zn bioavailability

Introduction

⇒Reduce plant phytate content.

Dietary Zn bioavailability

Major limiting dietary factor: Zn antagonism from phytate

OPO₃H- - HO₃PO Ca

2+Zn OPO₃H- -

HO₃PO Ca

OPO₃H- - HO₃PO Ca

2+Zn

⇒Supplement Zn supposed not to interact with phytate (organic Zn sources).

Hypothesis: Organic Zn sources are more bioavailable than inorganic Zn sources.

amidon

1

OPO₃H₂

5

2 OPO₃²-

3

OPO₃²-

4

-HO₃PO

6

2+Fe amidon

1

OPO₃H₂

5

2 OPO₃²-

3

OPO₃²-

4

-HO₃PO

6 1

OPO₃H₂

5

OPO₃H₂

5

2 OPO₃²-

3

OPO₃²-

4

-HO₃PO

6

2+Fe

Two databases (broiler, weaned piglets):

Material and method

Criteria for the choice of experiments:

o Minimum one treatment with an inorganic and one with an organic Zn source

Criteria for the choice of experimental treatment:

o Microbial phytase: 0 FTU/kg (piglets); < 500 FTU/kg (broiler)

o No other experimental factor than trace elements (amino acids, org. acids, …)

Two databases (broiler, weaned piglets):

Material and method

Broilers: 28 experiments, 175 treatments

Diets: synthetic, cereal-soybean meal, corn-soybean meal based

Dietary Zn content: 1 – 867 mg/kg

Inorganic Zn: oxide (8), sulfate (55), acetate (3), nitrate (1)

Organic Zn sources:

Piglets: 34 experiments, 159 treatments

Diets: cereal-soybean meal, corn-soybean meal based

Dietary Zn content: 17 – 3195 mg/kg Inorganic Zn: oxide, sulfate

acide aminé protéine ou peptide polysaccharide

acetate (3), nitrate (1)

Material and method: phase 1

Dose-response effect of dietary Zn

X1 Ymax

DZNTOT Y

Zn bioavailability is measured within the dose-response effect of a dependent variable.

=> Determination of X1 is necessary

Mathematical model: Non linear model (curvilinear-plateau)

If DZNTOT_wx ≤ X1, Y_wx = Ymax_w * (a + b*DZNTOT_wx + c*DZNTOT_wx²) + ɛ

wx

If DZNTOT_wx > X1, Y_wx = Ymax_w

DZNTOT: Dietary Zn content

Y_wx: Result from a dependent variable Y observed in experiment _wwith DZNTOT _x X1: DZNTOT value from when Y is maximized (Ymax)

b: slope a: 1 + 4*c*b² c: -b / 2*X1 ɛ: residual error

Results: phase 1

1000 800

600 400

200 0

250

200

150

100

50

0

Dietary Zn [mg / kg]

Bone Zn [mg / kg DM]

1000 800

600 400

200 0

2.5

2.0

1.5

1.0

0.5

0.0

Dietary Zn [mg / kg]

Plasma Zn [mg / l]

Dose-response effect of dietary Zn (example for plasma Zn and bone Zn)

Plasma Zn = -0.0171 + 0.0482*DZNTOT - 0.000275*DZNTOT² (X1 = 88; Ymax = 2.10; R² = 0.58; r.m.s.e = 0.158)

Bone Zn = 12.0 + 4.17*DZNTOT - 0.0233*DZNTOT² (X1 = 90; Ymax = 199; R² = 0.77 ; r.m.s.e = 13.2)

700 600 500 400 300 200 100 0

1.50

1.25

1.00

0.75

0.50

0.25

0.00

Dietary Zn [mg / kg]

Plasma Zn [mg / l]

Plasma Zn = -0.00214 + 0.0174*DZNTOT - 0.0000749*DZNTOT² (X1 = 117; Ymax = 1.03; R² = 0.49; r.m.s.e = 0.122)

Dietary Zn [mg / kg]

Dietary Zn [mg / kg]

180 160 140 120 100 80 60 40 20 0 150

125

100

75

50

25

0

Dietary Zn [mg / kg]

Bone Zn [mg / kg DM]

Bone Zn = 7.06 + 2.09*DZNTOT - 0.0105*DZNTOT² (X1 = 100; Ymax = 111; R² = 0.51; r.m.s.e = 9.96)

Material and method: phase 2

Mathematical model: General linear model Y_wxyz = a + a_w

+ b*DZNN_wx + c*DZNI_wy + d*DZNO_wz + f*DZNN²_wx + g*DZNI²_wy + h*DZNO²_wz

+ i*DZNN_wx*DZNI_wy + j*DZNN_wx*DZNO_wz + ε

wxyz

DZNN: native Zn source

DZNI: supplemented inorganic Zn DZNO: supplemented organic Zn

x, y, z : concentration de DZNN, DZNI, DZNO Y_wxyz: Result from a dependent variable Y observed in experiment _w, with Zn level _{x, y or z} a: intercept

a_w: Experiment effect b, c, d: linear coefficients f, g, h: quadratic coefficients i, j: coefficients for interactions ɛ: residual error

Bioavailability of Zn sources within dose-response effect

Y ɛ: residual error

Removal of experimental treatments for phase 2:

o When DZNTOT > X1 (Phase 1)

o When combined supplementation of DZNI and DZNO

o When DZNO and DZNI were not iso-dosed

DZNTOT

Results: phase 2

Bioavailability of Zn sources within dose-response effect

0.0 0.5 1.0 1.5 2.0

0 20 40 60 80 100

Plasma Zn [mg/l]

0.692 *** 6.44 n.s.

0.0155 ** 3.35 ***

0.0493 *** 4.78 ***

0.0446 *** 5.00 ***

-0.0333 ***

-0.0401 ***

-0.000945 *** -0.0544 ***

-0.000773 ** -0.0481 ***

DZNI DZNO

Model Coefficient P-value Coefficient P-value

Intercept DZNN DZNI DZNO

DZNI² DZNO² DZNN x DZNI DZNN x DZNO

Plasma Zn Bone Zn

[mg/l] [mg/kg DM]

Total Zn [m g/k g]

0 50 100 150 200 250

0 20 40 60 80 100

Total Zn [mg/k g]

Bone Zn [mg/kg DM]

-0.000773 ** -0.0481 ***

36 66

0.161 12.3

0.91 0.91

DZNI DZNO DZNN x DZNO

N°data R² r.m.s.e.

RBV: relative bioavailability of DZNO to DZNI

RBV average 93 113

DZNI vs DZNO DZNI²vs DZNO²

DZNN x DZNI vs DZNN x DZNO

n.s. n.s.

n.s. n.s.

- n.s.

Results: phase 2

Bioavailability of Zn sources within dose-response effect

DZNN

0.0147 *** 4.751 *** 0.757 *** 0.871 *** 0.214 ***

0.0125 *** 6.601 *** 0.736 ** 0.874 *** 0.250 ***

-0.000113 *** -0.0786 +

-0.000075 * -0.0835 *

N°data R² r.m.s.e.

Model Coeff. P-value Coeff. P-value Coeff. P-value Coeff. P-value Coeff. P-value

Intercept 0.508 *** 61.3 *** 251 *** 92.7 *** 44.4 *

-4.757 *** -1.051 * -1.211 +

DZNI DZNO

DZNI² DZNO²

28 20.98

46 23 23

Absorbed Zn

Liver Zn Bone Zn

ALP

0.0943 7.42

[mg]

[U/l]

23.833

0.90 2.982 0.96

0.91

0.93 0.92

[mg/l] [mg/kg DM] [mg/kg DM]

28 Plasma Zn

DZNI DZNO

DZNI DZNO DZNI

DZNO

0 5 10 15 20 25 30 35 40

0 20 40 60 80 100 120 140

Total Zn [m g/k g]

Absorbed Zn [mg / kg diet ingested]

0 20 40 60 80 100 120

0 20 40 60 80 100 120

Total Zn [m g/kg]

Bone Zn [mg/kg DM]

0.0 0.2 0.4 0.6 0.8 1.0 1.2

0 20 40 60 80 100 120

Total Zn [m g/kg]

Plasma Zn [mg/l]

r.m.s.e. 0.0943 20.98 23.833 7.42 2.982

DZNI vs DZNO

DZNI²vs DZNO² + - -

n.s. n.s. n.s.

n.s.

n.s.

- n.s.

RBV: relative bioavailability of DZNO to DZNI

RBV 85 98 97 100 117

Bioavailability of Zn sources in broilers and piglets

Discussion / conclusions

Bioavailability of native Zn (DZNN)

o In broilers: highly available ≈ supplemented Zn.

o In piglets: availability was reduced with increasing contents, most probably due to Zn antagonism from diet components such as phytate

Bioavailability of supplemented Zn sources (DZNI vs. DZNO) o In broilers: similar bioavailability

o

o In piglets: similar bioavailability

Possible reason (could not be tested in the present dataset)

oDZNN from plant origin is at least partially bound to phytate (ex. Rodrigues-Filho et al., 2005)

oIncreased dietary plant phytate reduces DZNN bioavailability, especially in piglets (ex.

Linares et al., 2007; Schlegel et al., 2010)

oPlant phytate does not interact with supplemental Zn (ex. Schlegel et al., 2010)

oA soluble Zn source, such as ZnSO₄ is therefore highly bioavailable in broilers and in piglets (ex. Schlegel et al., 2010)

Thanks a lot for your attention