Bart Buitenhuis*, N.A. Poulsen, L.B. Larsen, J. Sehested

Genetic Analysis of Micro- and Macro-elements in Danish Holstein

and Danish Jersey Milk

Introduction

Cell count, parity (1-3), lactation stage (wk 10-35), feed data

400 SDM, 400 Jersey cows, Milk and DNA, HD SNP array

Within the context of the DK-SE Milk genomics project:

Cell count, parity 1-3, lactation stage (10-35 weeks), feed data

Fatty acidsprofile

Protein profile

Coagulationproperties

NMR metabolomics

Milcoscanspectra

Mineral profile

• Physiological processes:• Ca and P play a role in the bone metabolism, • Se and Zn play a role in the immune system• Ca, K and Mg are involved in the maintaining the blood

pressure (Cashma, 2006; Haug et al. 2007; Overton and Yasui, 2014)

• Technological properties of milk:• Ca influences the coagulation

• Milk is a good source for minerals in human nutrition• How to influence milk mineral content?

Why minerals?

1. Estimate the heritability of the minerals in milk

2. Detection of QTLs for the minerals in milk using a

GWAS appoach

Aim of the study

Mean values IMacro elements

Mean values IIMicro elements

Mean values IIIAll minerals measured have a higher content in Jersey milkexcept for:

• Yijk = u + parityi + herdj + b*DIMijk + Ak + eijk

• h2 = 𝜎𝜎𝐴𝐴2

(𝜎𝜎𝐴𝐴2+𝜎𝜎𝑒𝑒

2)

heritability

Danish Holstein vs Danish Jersey

Trait h2

Ca 0.72 (0.36)Cu 0.28 (0.25)Fe 0 (0.22)K NCMg 0.08 (0.21)Mn 0.13 (0.17)Na NCP 0.46 (0.25)Se 0.10 (0.19)Zn 0.49 (0.24)

Trait h2

Ca 0.63 (0.31)Cu NCFe 0.15 (0.19)K 0.32 (0.21)Mg 0.57 (0.25)Mn NCNa 0.20 (0.19)P 0.29 (0.21)Se 0.20 (0.14)Zn 0.57 (0.22)

Pictures are from Viking Genetics

GWAS• Yijkl = u + parityi + herdj + b1*DIMijkl + b2*SNPk + Al + eijkl

• FDR < 0.10

GWAS Results I

Trait Danish Holstein Danish Jersey

Ca BTA14 BTA14CuFe BTA2; BTA24K BTA6MgMnNaP BTA1, BTA14Se BTA8Zn BTA2; BTA12

4 QTL for Danish Holstein and 6 QTL for Danish Jersey

GWAS Results II

Danish Holstein

PDIK1L

Plays a role in the serine/threonineprotein kinase activity

GWAS Results II

Danish Jersey

Casein cluster87.1-87.4Mb

Not annotated

• All minerals measured have a higher content in Jersey milk exceptfor K

• Ca, K, Mg and Zn have high heritabilities

• 4 QTL for Danish Holstein and 6 QTL for Danish Jersey

Conclusion