Control Of Mastitis Flashcards
What is the difference between individual and bulk milk SCCs?
Individual - milk from individual
- CMT
Bulk - done automatically by dairy on ALL milk received from farm
What is meant by the term: contagious mastitis?
What type of mastitis does it tend to cause?
Organisms prefer to live IN UDDER and teat skin
Most spread is from cow to cow and quarter to quarter at milking
Often cause subclinical infection
What type of mastitis does strep uberis cause?
Contagious AND environmental - can be associated with straw bedding
Why is staph aureus a tricky cause of mastitis?
Resistant to many antibiotics
Can be intracellular
How could minor pathogens be beneficial?
Low level infections may stop others invading
How does Environmental mastitis occur?
How does it present?
Bacteria live in the environment and sporadically gain entry to the udder.
Either rapidly eliminated or cause VERY SERIOUS mastitis
How long is the dry period?
Around 56 days
What does mastitis in the first 100 days of lactation imply?
Picked up in the dry period
How can environmental pathogens cause mastitis?
Contact with dirty environment
Milking
What environmental organisms may cause mastitis?
E Coli
Strep uberis
Klebsiella
Coliforms
(Bacillus cereus, fungi and yeast)
When might you suspect that Bacillus cereus is causing mastitis?
Cows fed brewers grains
When might you expect fungi and yeast to cause mastitis?
Usually after prolonged antibiotics
What cells are normally found in milk?
Somatic cells
— inflammatory cells
— Epithelial cells
When are epithelial cells high in milk?
Towards the end of lactation
Immediately after calving
ALWAYS PRESENT
When do inflammatory cells in milk increase?
BACTERIAL INFECTION
What cell counts indicate clinical and subclinical infection?
Clinical - millions per ml
Subclinical- more than 200 000 per ml
Describe the spread of subclinical mastitis.
Subclinical infection tends to go undetected and survive in a quarter for long periods
Causes prolonged mildly elevated SCC in that quarter
Spreads at milking time to other quarters/cows
MANY QUARTERS INFECTED
What does a high bulk tank SCC indicate?
High number of subclinical infections
High proportion of quarters infected
HIGH PREVALENCE of mastitis
What is the target bulk milk somatic cell count ?
less than 100,000 per ml
At what bulk milk SCC would you want to intervene?
More than 150 000 per ml
How can you control contagious causes of mastitis?
Control spread at milking Eliminate reservoirs of infection — dry cow therapy — culling — identify subclinically infected cows using individual cell counts
FIVE POINT PLAN
What is the five point plan?
Prompt detection and treatment of clinical cases
Post milking teat dip
Dry cow therapy
Cull persistent offenders
Regular servicing and maintenance of milking machine
How can you carry out ‘prompt detection and treat emend of clinical cases’?
Detection in parlour:
— stripping milk before, looking for clots and watery/serous milk
- also flushes out bacteria and aids milk let down
— strip milk into strip cup so doesn’t splash back and spread infection
— GOOD PARLOUR HYGIENE
- individual paper towels, one per cow
- wear gloves and CHANGE them
Why is it important to keep cows standing after milking?
How can this be achieved?
After milking, teat orifice remains open for 30-40 mins — want to wait for them to close.
Feeding after milking
How can post milking teat dips be administered?
Dip cup
Spray
Automatic exit systems
What are some examples of post milking teat dips?
Chlorhexidine
Quarternary Ammonium compounds
Chlorine based
Iodophors
What are the two main types of dry cow therapy?
Long acting antibiotics
Teat sealant
What are the aims long acting antibiotics in dry cows?
Remove existing sub clinical infections during dry period
Prevent further infections getting established during the dry period (e.g E. coli)
How are long acting antibiotics administered?
Why might this be problematic?
All quarters infused with a long acting (4 weeks) antibiotic at last milking
ANTIMICROBIAL RESISTANCE
What is teat sealant?
Inert substance infused into teat canal which blocks it
Prevents bacteria entering during the dry period
How should teat sealant and antibiotic be given?
ANTIBIOTIC FIRST, massage in
Then sealant, leave in teat canal
When should teat sealant not be used?
Active clinical mastitis
Will seal in infection
What should be remembered when giving teat sealant and antibiotics?
Hygiene must be excellent
Teat dip must be used beforehand
RECORD AND MARK to prevent cow getting milked by accident
FOLLOW WITHOLDING TIME and 96 hour post calving milk discard rule
When should cows with mastitis be culled?
3 clinical cases or more during one lactation
Persistent high individual SCC which does not respond to treatment
How could you avoid culling unless completely necessary ?
Separate problem cows from the rest of the herd.
Can work on curing them and make sure they wont infect rest of herd.
Milk them separately at the END
What is the role of the rubber liner in a milking machine?
Liner opens and closes to massage teat - otherwise would get painful as constant vacuum applied to teat end
Why is it important to change liners?
Can get cracked and harbour bacteria
Only part of machine that comes into contact with cow udder
What is a consequence of vacuum fluctuations in the milking machine?
Can cause retrograde movement of milk into teat canal
Milk from other quarters could get forced up - spread infection
How can you control environmental mastitis?
Control the environment
Parlour factors - teat preparation, clean and dry at time of applying milking cluster
What environmental factors can help reduce risk of mastitis?
Cubicles correct size
Comfortable bedding, not damp/mouldy
