40 years of breeding for improved disease resistance in dairy cattle

Presented by

Lars Peter Sørensen

Genetic Development Manager

VikingGenetics

www.vikinggenetics.com

Nordic countries: low use of antibiotics because …

Strict legislation regarding treatment of farm animals• Health agreement schemes – permits treatment of some diseases

Very high management level• High milk production requires healthy animals

Selective breeding for improved animal health• Udder health

• Claw health

• Metabolic and reproductive disorders

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Sale of antibiotics in European countriesSales in mg/PCU (Population correction unit) of veterinary antimicrobial agents marketed for food-producing

animals 2014 weighted according to the proportion of cattle in the countries EU member states

Source: European Medicines Agency, European Surveillance of Veterinary Antimicrobial Consumption; ‘Sales of veterinary antimicrobial agents in 29 European countries in 2015’

137.9

54.5

51.9

51.4

48.2

46.0

41.6

29.1

26.0

22.8

15.5

9.9

7.4

4.4

0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0

Italy

Germany

Poland

Spain

France

Portugal

Belgium

Ireland

Austria

Netherlands

United Kingdom

Finland

Denmark

Sweden

Weighted mg/PCU

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Nordic Total Merit (NTM)

All traits with an

economic value are included in

NTM

>90traits

combined in

14 trait groups

Production Health & Reproduction

Conformation

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Case: udder health

Low heritability: udder health 4% (milk yield ~30%)• Phenotype = 4% breeding + 96% environment

Unfavorable correlation with yield: yield ↑, mastitis cases↑

Genetic trend

Effect of breeding

Direct vs. indirect selection

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Udder health, genetic trend

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Genetic effect is

permanent and

cummulative

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Effect of breeding

Breeding value 80 90 100 110 120

Mastitis, % 17.4 14.7 12.0 9.3 6.6

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Number of daughters with mastitis in relation to the bulls’ breeding value for udder health

Source: Nordic Cattle Genetic Evaluation, 2020

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0

10

20

30

40

50

60

early stage of 1stlactation

middle and laststage of 1st lact

2nd lact 3rd lact

Mastitis treatments per 100 cows in 2008 and 2018, Danish Holstein

2008 2018

Effect of breeding and management

Simplification: difference between 2008 and 2018

• Less antibiotics used: 4,270 kg

• Less discarded milk: 17.2 mill. kg

• Less permanent milk loss: 54.9 mill. kg

Fact box

• Number of Danish Holstein cows: 325,000• Distribution on lactations: 1st: 40%; 2nd: 35%; 3rd+: 25%

• Lactation yield, kg: 1st: 8,689; 2nd: 10,162; 3rd+: 10,582

• Milk discarded for 8 days because of treatment with antibiotics• Permanent milk loss of 10 % restored

• 63 g antibiotics per treatment

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Direct vs. indirect selection

Direct registrations: mammary treatments since early 1980s

Indirect measures: somatic cell count, fore udder attachment and udder depth

Advantage of direct recordings is higher reliability of breeding values → increased genetic progress

Udder health weighted according to actual cost → balanced breeding goal

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DATA IS KING!

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Effects of improved udder health

Fewer treatments → less use of antibiotics

Better food safety, less discarded milk and better milk quality

Improved longevity → lower replacement rate

Improved animal welfare

Fewer replacement heifers are needed → increased use of beef semen• Lower environmental and climatic impact from beef crosses

Improved economy for herd owner

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WIN WIN SITUATION FOR SOCIETY ☺

Thank you!

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