Milk Hygiene

Question 1

composition of cow milk

Answer 1

mixture of fats, proteins, carbohydrates, minerals, vitamins and water

Question 2

NCIMS

Answer 2

National Conference on Interstate Milk Shipments

Question 3

grade A milk

Answer 3

defined and regulated by the Pasteurized Milk Ordinance
milk for liquid consumption and any milk in interstate commerce
cheese, butter, ice cream and other dairy products are made from Grade A

Question 4

True/False: milk is biologically sterile

Answer 4

False:

• mastitis organisms
• bacteria in the teat canal
• bacteria from the skin of the teat
• post-harvest contamination

Question 5

causes of high bacterial counts

Answer 5

Milking dirty cows
Cleaning water temperature and volume
Cracked rubber parts
Dirty gaskets
Biofilm, particularly in bulk tank
Inadequate cleaning of bulk tank.
mastitis bacteria

Question 6

sanitation

Answer 6

starts with the premises (milking parlor, equipment, yard/pasture)
cows (udder, flanks bellies, tails; teat dip)
personnel (hand washing!)

Question 7

storage

Answer 7

Milk is stored on the farm in refrigerated, usually stainless steel, bulk milk tanks
Under the PMO milk may be stored for up to 4 days in this tank

Question 8

transport

Answer 8

insulated tanker trucks
tested for antibiotic residues before it is unloaded
may pick up from more than one farm

Question 9

milk receiving station

Answer 9

Milk is analyzed for bacteria, somatic cell counts, and composition (fat and other components)

Question 10

clarifier

Answer 10

remove sediment

Removes dirt, straw, blood, somatic cells, manure, NOT bacteria

Question 11

separator

Answer 11

separate milk with different amounts of fat

Question 12

pasteurization

Answer 12

Brief heating is used to kill common pathogens in milk; milk is not sterile
Pasteurization is currently based on the thermal death of Coxiella burnetii

Question 13

Batch pasturization

Answer 13

Entire vat is heated and held at temperature for the appropriate length of time

Question 14

continuous-flow pasturization

Answer 14

Milk flows through a heated tube, with a carefully monitored transit time and temperature
Less of a “cooked” flavor than seen with batch methods

Question 15

true/false: for cheese and cottage cheese there is no bacterial limit

Answer 15

true; coliform

Question 16

after pasteurization

Answer 16

Cooled to

Question 17

sources of microbes

Answer 17

Udder: infections of the udder
Exterior of animal: dirt/mud, feces, hair, etc.
Air: dusts, aerosol, etc
Milking equipment
Personnel
Water

Question 18

mastitic milk

Answer 18

Increased blood proteins and leukocytes in milk

Decreased milk yield

Question 19

true/false: 5-10% of cows may produce abnormal milk at any one time

Answer 19

true

Question 20

mastitis cases=

Answer 20

high SCC and low production

Question 21

legal maximum SCC for Grade A cow’s milk in the USA

Answer 21

750,000 cells/mL

Question 22

1 cowside test for mastitis

Answer 22

California mastitis test (CMT)

Question 23

mastitis screening test

Answer 23

California mastitis test (CMT)
Electrical conductivity
Mammary associated amyloid A
Bacteriologic cultures

Question 24

sale of unpasteurized milk

Answer 24

Belief that nutrients are lost by pasteurization
Belief that pasteurization causes milk allergies
Illegal in most states
“Cow- Shares”