Milk (Exam 2) Flashcards
What are the different types of milk harvesting housing?
Tie stall barn: pipeline system above cow to carry milk from udder to bulk storage; stay in dry feed lots/barn; into holding pen; into milking parlor with doors open, walk in voluntary, door closes automatically
Parallel parlor: straight back
Herringbone parlor: angled
Rotary parlor
All these styles have pipelines below cows = good for milk as gravity pulls down and don’t ruin the quality of milk
How is milking prepped?
Stimulation of milk let down and pre-stripping
Udder clipped/hair singed
Pre-dip
Single cloth towels
Backflush
Add Machine
Machine automatically released
What occurs with stimulation of milk let down and pre-stripping?
Allow milk to squirt out to evaluate (45-60s)
Cows with mastitis are held out and not milked into the lane (puss in milk)
Why/how are udders clipped/long hairs singed?
With cool flame
To prevent dirt and debris introduced in milk
What is the purpose of pre-dip?
Stimulates teats and allows milk to come down (0.5% iodine)
What is the purpose of single-cloth towels?
Removes pre-dip after 30 seconds of contact time
Teats clean and ready for machine application
Define: Backflush and Machine Add On
2 vacuum system and massaging system
Pulsation mimicking calves
If suction too hard, start pulling blood and damages cap, ducts, and teat
What is the purpose of the machine automatically releasing?
Measures milk let down and identifies when low milk volume
What steps are taken to confirm that the cow is healthy and that the milk she produces is wholesome for consumption?
Each cow’s udder evaluated for heat, swelling, and pain to determine if milk is suitable for milking
Pre-stripping allows milk to squirt out before milking to evaluate the milk
Testing for mastitis of other infectious diseases that could lead to spoilage/bad/taste/dangerous milk
What is the Pasteurized Milk Ordinance?
PMO
Make high quality product with low pathogens/bacteria
Govern design and maintenance of dairy farms and processing plants to make sanitation and milk quality uniform across state lines (adopted by most states
What regulations are in the pasteurized milk ordinance?
Standard for milk harvest, storage, transport, cow facilities, equipment specification, cleaning processes
Inspections and oversights
Testing milk
Allowable limits for test results
Pasteurization standards
Packaging and handlin
How does mastitis affect the cow, the milk, the quality of the milk, and the safety of the milk?
Inflammation of mammary gland = influx of inflammatory cells and mediators
Most commonly due to bacterial infection
Most common infectious disease of lactating cows
Cause disease in cow = cow health problem
NOT FOOD SAFETY PROBLEM
YES FOOD QUALITY PROBLEM = increase somatic cell count, milk composition changes
Abnormal milk/milk quality
Most common reason for antibiotic use in dairies (drug residue is major concern, withdrawal time after use)
What are the clinical signs of mastitis in cows?
Local infections of udder = redness, swelling, heat, pain
Milk = clots, thick/thin, color
Systemic = fever, tachycardia, diarrhea, weakness, death
What are the somatic cell tests?
California mastitis test: rapid; add milk to wells, add reagent, color change test = coagulates somatic/enucleated cells
Electronic SCC: test large numbers of individual cows (commercial dairies) monthly = look at summary (% up/down, compare parity/age, % herd with low SCC)
What are the normal/high SCC values?
Normal: <250k
High Quality: <100k
Mastitis: >300K
How is mastitis managed?
Bacterial culture: key to appropriate management of problem herds, determine why high SCC (sample from each teat and test)
Intramammary antibiotic infusion: routine treatment (inject locally, better tx than systemic)
What are the bacterial sources of milk contamination?
Teat skin/canal (commensals)
Machine liners/tubers (improper procedures, cleaning, water temperature)
Mastitis
Systemic infections
Contaminants
What are zoonotic pathogens in milk?
Pasteurization prevents disease spread!
Salmonella
E. coli
Campylobacter
MAP (feces)
Cryptosporidum
What are bacterial pathogens that threaten animal health?
Mastitis
What are bacterial pathogens that threaten milk spoilage?
Majority of bacteria in milk = spoilage bacteria
Psychotropic bacteria (spoilage)
Thermoduric bacteria (reduce shelf life) = micrococcus, microbacterium, lactobacillus, bacillus, clostridium
How is milk moved on the farm and from the farm through the processing system?
Modern milking system = use pipelines to move milk faster, reduce exposure to air, chilled faster
Move to receiver tube to cooling tubes (plate coolers) to tank room/bulk tank
Agitator running to keep milk at right temp
Loaded onto trucks to be processes at milk plant
What processes are used to assure highest milk quality?
Cooling/chilling to prevent microbial growth/spoilage (chilled and stored <40F)
Filtered to remove debris
Removed from farm to processing within 48 hours
Less exposure to air
Pipes moving downwards to not impact quality of milk
Pasteurization
How have technological advances improved milk quality?
Automatic milking systems robotic milkers
Dairy tech pasteurizer
Define: Dairy Tech Pasteurizer
Turbulent to take out clumps of pathogens and kill them off
More pipelines to increase movement of milk under certain temperatures to deliver to pasteurization
HTST method of pasteurization: milk in tank at low temperature (<40F) leaves from one tube to regenerator
Adjacent milk pipe is hot, leaving pasteurization and back to tank (low temp): hot milk warms up cold milk and vice versa
Additional heating phase added to bring milk >72F held for 15 seconds, then regenerated back to cooler temps
Energy efficient and neutralize pathogens
