5 Milking Management 1 Flashcards
Explain the physiology behind milk ejection
Mechanical stimulation of teats leads to oxytocin release from posterior pituitary
Oxytocin reaches the mammary gland via blood circulation, binds to receptors of myoepithelial cells
Myoepithelial cells contract, milk evacuation from mammary gland
What is epinephrines role in milk ejection
Prevents oxytocin from binding its receptors when cow is excited, nervous, fearful
How does milk evacuate the mammary gland
Vacuum pressure (calves, milking machines) or mechanical forces (hand-milking)
Four basic steps of milking routine
- Pre-milking teat disinfection
- Fore-strip
- Machine attachment/detachment
- Post-milking disinfection
Describe the pre-milking teat disinfection
Wear gloves or disinfect hands
Kills bacteria on teat skin surface
Contact time needed: 20-30 seconds
Pay close attention to teat ends - where the milk comes out
Describe the fore-strip process
Eliminate bacteria in the ends of all four teats
Helps detect mastitis (abnormal milk in one teat)
Strongest stimulus for milk let-down; allows natural milk ejection process
Describe attaching the milking unit
Attach within 60-90 seconds after stimulation
Minimal air admission during claw attachment
Adjust milking cluster so weight is evenly distributed, aligned so teats are not twisted and liners don’t squawk
Slides 17-19
Prep vs no prep & oxytocin
What is the ‘ideal milking routine’
Udder prep: 10-20 sec/cow
Attachment delay: 40-70 sec/cow
Total prep-lag time: 60-90 sec/cow
How do you assess completeness of milking?
Using residual milk
250-500ml = ideal
> 500 ml = under milking
<250 ml = over milking
Describe post-milking disinfection
Full teat coverage for each teat
Spray may not adequately cover entire teat
Dipping cups use less disinfectant
Overarching goal for a milking routine
Every cow should be milking exactly the same at every milking for her entire lactation
Consistent routine! Cows are creatures of habit
Good milking management will… (3)
- increase milk production and udder health
- increase labour efficiency
- decrease new intra-mammary infections
Mastitis definition
Inflammation, infection or trauma of the breast or mammary gland
Causes of mastitis
99% are bacterial infections
Rarely: algae, yeast
Very rarely: viral
Symptoms of mastitis
Inflammation = gross swelling, redness, heat, pain
Loss of function (yield and composition)
Clinical mastitis signs
Visible clots (leucocytes), swelling & redness, serum/blood in milk, pain, high SCC and LS< milk loss
How often should clinical mastitis occur in well managed herds?
~1% of cows
Subclinical mastitis signs
Normal appearing milk
Elevated SCC (>200,000)
Elevated LS (>4)
Milk loss
May affect large percent of herd
What are the contagious mastitis pathogens?
- Streptococcus agalactiae
- Staphylococcus aureus
- Mycoplasma bovis
- Prototheca