MASTITIS EPIDEMIOLOGY - UMN College Vet MedMASTITIS EPIDEMIOLOGY Sarne De Vliegher Head of M-team UGent & Mastitis and Milk Quality Research Unit @ UGent The 2nd University of Minnesota

MASTITIS EPIDEMIOLOGY

S a r n e D e V l i e g h e r

H e a d o f M-teamUGent

& M a s t i t i s a n d M i l k Q u a l i t y R e s e a r c h U n i t @ U G e n t

The 2nd University of Minnesota China Dairy Conference

Hohhot

OVERVIEW Mastitis epidemiology Multifactorial disease Multifactorial approach Conclusions

2 © M-teamUGent


3 © M-teamUGent

Risk of mastitis Generally speaking: risk of mastitis is determined by an equilibrium between

= Basis for prevention

EXPOSURE TO MASTITIS PATHOGENS

BOVINE DEFENCE MECHANISMS

Bac

Far Cow

Q Q Q Q

© M-teamUGent

4

Multiple players

Risk

Bacteria

Farmer Cow

Q Q Q Q

© M-teamUGent

Bacteria Cow

Quarter Farmer

5

Multiple players - stratification

Based on the structure of the cell wall: – Gram-positive (e.g. Staphs, Streps) – Gram-negative (e.g. E. coli) – Pathogens without cell wall (e.g. Mycoplasma)

Based on ecology: – Cow-/udder-adapted pathogens (e.g. Strep. agalactiae) – Environmental pathogens (e.g. Klebsiella)

© M-teamUGent

Bacteria

6

Multiple players - stratification Based on the virulence characteristics:

– Major pathogens (e.g. Staph. aureus) – Minor pathogens (e.g. Corynebacterium bovis)

Based on the epidemiology: – “Contagious pathogens” (Staph. aureus)

– “Opportunistic pathogens” (Pseudomonas)

© M-teamUGent

Bacteria

7

Mammary gland and/or teat skin = predominant reservoirs of infection

Need the cow/udder to survive and multiply

Transmitted from the infected cow or quarter to the teats of non-infected cows/quarters during the milking process via hands, cloths, teat liners …

Colonies become established at the teat end and slowly grow through the canal over 1-3 days

© M-teamUGent

“Contagious pathogens”

Bacteria

8

Environment = reservoir of infection

Do not need the cow/udder to survive and multiply

Transferred from the environment to teats between milkings

Penetration teat canal occurs either between 2 milkings when teats are in close contact with stall floor or by propulsion on a reverse flow of milk

Many new IMI occur during the dry period

© M-teamUGent

“Environmental pathogens”

Bacteria

9

Multiple players

© M-teamUGent

Cow

Multiple factors

Position Lesion Colonised SCC Hyperkeratosis …

Age

Breed

Lactation stage

Genotype

Milk yield level

…

Quarter

10

© M-teamUGent

0

5

10

15

20

25

30

35

40

45

50

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

Qua

rter

cas

es p

er 1

0,00

0 co

w-d

ays a

t ris

k

Week after calving

Heifers

Cows

… Differences between cows … ... Clinical mastitis incidence in Flanders …

Verbeke et al, 2015 11

Cow

© M-teamUGent

… Differences between quarters …

12

Quarter

Multiple players “Quick and not-so-clean” vs “clean and accurate”

Motivated vs non-motivated

Hard-to-reach vs easily- reached farmers

…

© M-teamUGent

Farmer

13

© M-teamUGent

… Differences between farmers …

Mul

tifa

ctor

ial d

isea

se

14

Farmer

Hypothetical quarter with the lowest probability of having/getting IMI

– left front quarter with a teat-end of impeccable quality,

colonized with CNS, a SCC of 50x10³ cells/mL, high proportion of viable milk PMN, no history of IMI ...

– belonging to a late lactating, healthy, unstressed heifer, with a clean udder, without nutritional deficiencies, and not too high producing ...

– managed by a clean, accurate, motivated, easily-reached farmer in a spotless, well-ventilated stable ...

© M-teamUGent

Quarter

Farmer

Cow

15

Hypothetical quarter with the highest probability of having/getting IMI

– right hind quarter with a teat-end with severe

hyperkeratosis and a lesion, colonized with S. dysgalactiae, a SCC of 1000x10³ cells/mL, lots of apoptotic milk PMN, and a history of CM ...

– belonging to an early lactating, BVDV-infected, lame, stressed cow in 8th lactation, with a dirty udder, deficient in vit E and se, and very high producing ...

– managed by a quick and not-so-clean, non-motivated, difficult-to-reach farmer in a messy, dark, non-ventilated stable ...

© M-teamUGent

Quarter

Farmer

Cow

16


17 © M-teamUGent

Mastitis: multifactorial approach Mastitis is a complex disease

– Multiple players (bacteria - cow/quarters - farmer) – Multiple factors explaining variability in susceptibility

General strategy – Based on 2 simple principles – Application of (adapted) NMC 10-point prevention and

control program

© M-teamUGent

18

General strategy 2 Simple principles of mastitis prevention and control

program:

Treatment of cows likely to cure Culling (segregation) of cows unlikely to cure

↓ Exposure of animals to bacteria ↑ Susceptibility/resistance of animals against infections

© M-teamUGent

2. Prevention of New infections (N)

1. Appropriate action for Existing infections (E)

OR

AND

19

10 POINT PROGRAM 1. Excellent milking technique N

Appropriate action for Existing infections (E)

Prevention of New infections (N)

20 © M-teamUGent

© M-teamUGent

21

10 POINT PROGRAM 1. Excellent milking technique

2. Well-functioning milking machine

N

N



22 © M-teamUGent

© M-teamUGent

23



3. Excellent comfort and hygiene

N

N

N



24 © M-teamUGent

25




4. Correct treatment of subclinical and clinical mastitis

N

N

N

E + N



26 © M-teamUGent

27 © M-teamUGent





5. Culling of chronic cases

N

E + N

N

N

E + N



28 © M-teamUGent






6. Optimal dry-cow management

N

E + N

N

N

E + N

E + N



29 © M-teamUGent

30 © M-teamUGent







7. Excellent heifers management

N

E + N

N

N

E + N

N

E + N



31 © M-teamUGent

32 © M-teamUGent








8. Excellent animal health / immunity

N

E + N

N

N

E + N

N

E + N

E + N



33 © M-teamUGent

34 © M-teamUGent









9. Improved breeding policy

N

E + N

N

N

E + N

N

E + N

N

E + N



35 © M-teamUGent

36 © M-teamUGent










10. Monitoring/evaluation

N

E + N

N

N

E + N

N

E + N

N

E + N



37 © M-teamUGent

E + N

Step 1: Somatic cell count analysis + clinical mastitis

cases

Step 2: Milk sampling high SCC cows +

clinical mastitis cases

Step 3: Bacteriological culturing − Gram-pos. versus gram-neg. − Major and minor − Contagious versus environmental

Step 4: Making decisions SCM

→ treating → re-sampling → waiting → culling

Treatment plan CM

- Adapt prevention and control

program -Revise the aims

© M-teamUGent

38










10. Monitoring/evaluation

N

E + N

N

N

E + N

N

E + N

N

E + N

Farmers’ motivation



Advisors’ communication 39 © M-teamUGent

E + N


40 © M-teamUGent

Conclusions Mastitis is a multifactorial disease with multiple

players

Implementation of the 2 basic principles (existing cases and new cases) via the (adapted) NMC 10 point program = basis for excellent udder health

© M-teamUGent

Thank you

© M-teamUGent

Documents

MASTITIS EPIDEMIOLOGY - UMN College Vet MedMASTITIS EPIDEMIOLOGY Sarne De Vliegher Head of M-team UGent & Mastitis and Milk Quality Research Unit @ UGent The 2nd University of Minnesota