Mastitis Flashcards
(196 cards)
Environmental mastitis pathogens
E.coli
Streptococcus uberis
Klebsiella
Contagious mastitis pathogens
Streptococcus uberis Streptococcus dysgalactiae Streptococcus agalactiae Staphylococcus aureus Coagulase negative staphylococci Mycoplasma
How does sub-clinical mastitis present?
No visible signs
Changes in SCC
Reduced milk quality and yield
How can you grade clinical mastitis?
1a - mild changes in the milk
1b - acute milk changes + udder hot and painful
2c - chronic changes in milk + udder hard and lumpy
3 - changes in the milk and udder + cow sick
What are the outcomes of mastitis infection?
- Clear the infection and return to normal milk production
- Persistently infected - spreads amongst the heard
- Permanent damage to the udder causes a reduced milk yield
- Death - toxaemia
How can the the teat skin be damaged to predispose a cow to mastitis? And how can you protect the teat skin?
Bruising, chapping, trauma
Teat lesions
Damage by the milking machine
Methods to protect the teat skin:
- post-milking teat dipping
- prompt treatment of teat lesions
- good milking machine function
When can bacteria invade the teat canal? And how is the teat canal damaged?
When open during and after milking - takes about 20-30 minutes to close
Keratin forms a seal over the teat end when the cow is dried off
Damage to the teat canal occurs by:
- milking machines
- trauma to the teats
- teat lesions
- teat cannula
What causes Teat end hyper keratosis?
Excessive milking vacuums
Worn teat liners
Faulty pulsations
Liner type
When are cows at most risk of acquiring new mastitis infections?
Early dry period
Late dry period
When do most clinical mastitis cases occur?
1st 6 weeks post calving
Why are cows predisposed to acquiring mastitis infections in the dry period?
Cessation of milking - increased intra-mammary pressure and widening of the teat canal Bacteria not flushed out No teat dipping Poor formation of the keratin plug WBC function is reduced
What nutrition factors can lead to mastitis?
Negative energy balance
Vitamin E and Selenium
Sub-acute Rumenal Acidosis
Hypocalcaemia
What does the mastitis vaccine protect against?
Staph aureus
Coliforms
Coagulase negative staphylococci
What are the housing requirements for a cow?
Lying area Loading area Feed space Safe flooring and passageways Water supply Slurry handling
How much loafing area should cows have?
120% of cubicle area
How much feed barrier space must a cow have?
60cm per milking cow
90 cm per dry cow
How much water space must a cow have?
10cm per cow
How much lunge space does a cow need?
0.7 - 1m lunge space
What does the stack effect require?
Inlet above the outlet
Sufficient body mass to generate heat to move the air
5 freedoms
Freedom from hunger and thirst Freedom from pain injury and disease Freedom from discomfort Freedom to express normal behaviour Freedom from fear and distress
What lighting should you provide for cows?
16-18 hours per day
Increases yield by 2 L
10% of the roof area should be transparent
What is the stocking density of loose housing?
1.3 m squared / 1000 kg of herd milk production
What are advantages and disadvantages of loose cow housing?
Comfortable so reduced lameness
Increased requirement for trimming
Straw is expensive
Increases Streptococcus uberis risk
Poor hygiene
High cell counts
How should you maintain loose straw housing?
Clean out every 2 weeks
Bale down 3 times a week
Store dry bedding under cover
Have a sand drainage layer that can be replaced every few months
Completely clean out straw every 2 weeks
Clear divide between bedding and standing