Genetics, a tool to prevent mastitis in dairy cows

Transcription

1 La génétique, un levier pour mieux maîtriser les mammites chez les vaches laitières Genetics, a tool to prevent mastitis in dairy cows 9 sept 2016 Stéphanie Minéry 1

2 Outline Udder Health, selection is possible 20 years of genetic selection in France Genetic results, Genomic benefits, Economic gains Genetics, a tool to prevent mastitis 2

3 UdderHealth, selectionispossible Somatic Cell Count (SCC) and Clinical Mastitis (CM) have strong genetic correlation ( ) SCC has higher heritability than CM (15% vs 3%) CM has significant genetic variability (σ g = 6%, range of breeding values = 30%) Efficient genetic improvement is possible for CM. Selection for lower SCC is relevant to increase the resistance to both clinical and subclinical mastitis Rupp & Boichard, 2003 Govignon-Gion A. et al.,

4 Udder Health, 20 years of selection in France SCC SCC records in the national database First SCC EBV SCC EBV Included in Global Merit INDEX (ISU) SCC : Monthly collected during milk recording. Count Score (log transformation) : SCS Data of lactation 1 to 3 4

5 Udder Health, 20 years of selection in France SCC SCC records in the national database First SCC EBV SCC EBV Included in Global Merit INDEX (ISU) Clinical Mastitis Clinical Mastitis recording First CM EBV Binary trait : 0 vs>0 clinical mastitis events, collected during the first 150 days in milk; Recorded by milk recording technicians Data in lactations 1 to 3 5

6 Udder Health, 20 years of selection in France SCC SCC records in the national database First SCC EBV SCC EBV included in Global Merit INDEX Clinical Mastitis Clinical Mastitis recording First CM EBV Only a few countries use CM data for evaluation: France, Denmark, Finland, Sweden, Norway, Canada, Netherlands 6

7 Udder Health, 20 years of selection in France SCC SCC records in the national database First SCC EBV SCC EBV Included in Global Merit INDEX CM EBV included in Global merit INDEX (ISU) & Udder Health INDEX Clinical Mastitis Clinical Mastitis recording First CM EBV Udder Health INDEX (STMA) 7 7

8 Breeding Objectives ISU 2001 Holstein ISU 2012 Udder Health 18% 13% 8

9 SCC EBV are efficient Percent of SCC > cel/ml Cow value = -123 % SCC > COW value = + 1 ONLY 5 % SCC > HOLSTEIN data, born from 2008, Lactation 1 (Idele, INRA, 2016) SCC EBV of Cows 9

10 SCC EBV are efficient Percent of SCC > cel/ml Cow value = -123 % SCC > Cowwithgood SCC EBV = LowerSCC in milk COW value = + 1 ONLY 5 % SCC > HOLSTEIN data, born from 2008, Lactation 1 (Idele, INRA, 2016) SCC EBV of Cows 10

11 CM EBV are efficient Percentage of lactations with clinical mastitis (CM) Cow value -1: 19 % of lactations with CM COW value + 1 : ONLY 6 % of lactations with CM NORMANDE data, born from 2008, Lactation 1 (Idele, INRA : 2016) CM EBV of Cows 11

12 CM EBV are efficient Percentage of lactations with clinical mastitis (CM) Cow value -1: 19 % of lactations with CM Cow with good Clinical Mastitis EBV = Few cases! COW value + 1 : ONLY 6 % of lactations with CM NORMANDE data, born from 2008, Lactation 1 (Idele, INRA : 2016) CM EBV of Cows 12

13 Improvement of genetic level of bulls STMA (Udder health) INDEX (Note : positive index => less mastitis) Example in HOLSTEIN, bulls used for AI SCC Included in Global Merit Index (ISU) Genomic EBV CM included in Global Merit Index (ISU) First SCC EBV 13

14 Improvement of genetic level of bulls STMA (Udder health) INDEX (Note : positive index => less mastitis) Example in HOLSTEIN, bulls used for AI SCC Included in Global Merit Index (ISU) Increase in genetic level of bulls used in AI Genomic EBV CM included in Global Merit Index (ISU) First SCC EBV 14

15 Improvement of genetic level of cows SCC EBV Example in HOLSTEIN, cows (Note : positive index => less SCC) Year of birth SCC included in Global Merit Index (ISU) 15

16 Improvement of genetic level of cows SCC EBV Example in HOLSTEIN, cows (Note : positive index => less SCC) Increase of genetic level of cows Year of birth SCC included in Global Merit Index (ISU) 16

17 Genomic benefits From 2009 for Males and 2011 for Females : Genomic information used to estimate G(enomic)EBV A simple ear punch sample ADN chip GENOMIC EBV = More efficient Selection Genetic Value known earlier, as animals are very young Precise information even for Cow More information for each animal 17

18 Genomics, for a better choice of heifers An example INDEX ADELE & ATHENA (Mario*Giana) NO genotyping SCC 0.2 Clinical Mastitis? WITH Genotyping ATHENA Better for Udder Health ATHENA (Mario*Giana) ADELE (Mario*Giana)

19 Economic gains +1 SCC EBV +1 CM EBV Possible economic gain for +1 EBV value / cow/ year + 55 /cow/year + 10 /cow/year Impacts Milk Quality payment Veterinary costs Zootechnical losses Results from OSIRIS Project Impacts Veterinary costs Zootechnical losses Evaluated in an intensive system, Holstein cows, Northern France, Milk specialized, 9000 L /year/ cow. 19

20 % SCC > cell/ml Genetics, only one of the many tools for mastitis control Good herd conditions (good health, good feeding ) 7 % 3 % Bad Sire Genetic level Good 20

21 % SCC > cell/ml 29 % Genetics, only one of the many tools for mastitis control Good herd conditions (good health, good feeding ) 13 % Poor herd conditions (bad health, milking machine problem ) 7 % 3 % Bad Sire Genetic level Good 21

22 % SCC > cell/ml 29 % Genetics, only one of the many tools for mastitis control Bad genetics ANDbad herd conditions= HIGHEST Somatic CELL Count Bad 7 % Sire Genetic level 3 % 13 % Good Good genetics ANDgood herd conditions = MINIMUM of Somatic CELL Count 22

23 % SCC > cell/ml Bad 7 % 29 % Genetics, only one of the many tools for mastitis control Sire Genetic level Bad genetics ANDbad herd conditions= HIGHEST Somatic CELL Count Genetics for the basement, but don t forget the good 13 % practices! 3 % Good Good genetics ANDgood herd conditions = MINIMUM of Somatic CELL Count 23

24 National SCC results= combinationof Geneticsand Practices on Farm x1000 scc/ml SCC Herd Conditions Genetics Index Decrease of SCC : Increase in genetics but decline of herd conditions: SCC stable From 2015 : Increase in genetics and herd conditions: Decrease of SCC. 24 Holstein

25 Breeding Objectives on farm level 4 years lag between mating decisions and future dairy cows producing in the herd GENETICS = medium/long term results Choose a direction, and keep it at least 5 years, to see results in the herd. 25

26 Conclusions French breeders have genetic tools to prevent mastitis. SCC and Clinical Mastitis EBV are efficient, with results on economic gain. With Genomic tools (genotyping), breeders can improve heifers choices. Genetics = a tool for medium/long term results. Continue to focus on good practices, as recommended by the French national plan to prevent mastitis. 26

27 This afternoon Session 7 17:15 27

28 Thanks UMT 3G INRA - ALLICE Anne Barbat, INRA Nadine Ballot, CNIEL Pascale Le Mezec, IDELE Philippe Roussel, IDELE 28