Control of Mastitis

Question 1

What are the two major categories of mastitis?

Answer 1

Contagious

Environmental

Question 2

Describe contagious mastitis…

Answer 2

Organisms prefer to live in the udder and teat skin
Often subclinical
Mostly spread from cow to cow at milking

Question 3

Outline the major pathogens associated with contagious mastitis…

Answer 3

Strep agalactiae
Strep dysgalactiae
Staph aureus
Strep uberis

Question 4

Which mastitis-causing pathogen is associated with damp straw?

Answer 4

Strep uberis

Question 5

Which mastitis-causing pathogen is associated with wood shavings?

Answer 5

Klebsiella

Question 6

Describe environmental mastitis…

Answer 6

Linked with a dirty environment
Environmental pathogens sporadically gain access to udder
Usually either rapidly eliminated or cause very serious mastitis
If quarter is infected during dry period can persist and cause problems in early lactation

Question 7

List some important husbandry aspects associated with minimising environmental mastitis…

Answer 7

Hosuing design
Cubicle design
Yard management
Scraping of dung
Dry cow housing

Question 8

Outline the major pathogens associated with environmental mastitis..

Answer 8

E coli
Strep uberis
Klebsiella
Coliforms
Bacillus cereus
Fungi
Yeasts

Question 9

Which somatic cell types are always found in milk?

Answer 9

Inflammatory

Epithelial

Question 10

When are milk levels of epithelial cells usually high?

Answer 10

End of lactation
Immediately after calving
Bacterial infection

Question 11

Give a somatic cell count for milk from a cow with clinical mastitis…

Answer 11

millions cells/ml

Question 12

Give a somatic cell count for milk from a cow with subclinical mastitis…

Answer 12

> 200,000 cells/ml

Question 13

What is a target bulk milk somatic cell count?

Answer 13

> 100,000 cells/ml

Question 14

What is an intervention level bulk SCC?

Answer 14

150,000 cells/ml

Question 15

At that bulk milk SCC is financial penalty incurred?

Answer 15

200,000 cells/ml

Question 16

Outline the 5 point plan for control of contagious mastitis….

Answer 16

1. Prompt detection and treatment of clinical cases
2. Post milking teat dip
3. Dry cow therapy
4. Cull persistent offenders
5. Regular servicing and maintenance of milking machine

Question 17

At what level does a cow become a persistent offender of mastitis?

Answer 17

3 or more cases of clinical mastitis per lactation

Persistently high individual SCC that does not respond to treatment

Question 18

Suggest 4 agents used for post-milking teat dips…

Answer 18

Iodophores
Chlorein-based agents
Chlorhexidine
Quarternery ammonium compounds

Question 19

Suggest 3 methods for postmilking teat dipping…

Answer 19

Dip cup
Spray
Automatic exit systems

Question 20

What are the 2 main methods of dry cow therapy?

Answer 20

Long-acting antibiotics

Teat sealant

Question 21

Outline the use of long-acting antibiotics in dry cow therapy…

Answer 21

Aims to remove existing subclinical infections during the dry period
All quarters infused with antibiotics at last milking
Greatly improved efficacy over lactation therapy
Prevents infection establishing during dry period

Question 22

What is the only part of the milking machine that regularly comes into contact with the udder?

Answer 22

Liner

Question 23

What is liner slip?

Answer 23

Air leaking into top of liner (makes distinct sound)