Milk Hygiene

Question 1

8 step process from cow to consumer

Answer 1

1. rearing
2. harvesting (hand or machine milking)
3. storing
4. transportation (but first testing)
5. lab testing - aroma, temp, pH, drug residue
6. processing
7. packaging
8. selling

Question 2

required hygienic practices

Answer 2

• animal hygiene
• milker’s hygiene
• utensils and equipment hygiene
• hygiene during milking process
• environmental hygiene

Question 3

feed must be free from

Answer 3

• biological hazards
• chemical hazards
• physical hazards

Question 4

what can minimize soiling and improve animal comfort

Answer 4

good bedding

Question 5

water consumption per 1000 L of milk

Answer 5

1000-5000 per 1000 L of milk

Question 6

water used to wash equipment and cow standings during and after milking

Answer 6

potable water

Question 7

structures

Answer 7

• minimize risk of contamination
• floors impervious to water and free draining
• suitable draining system
• smooth doors and walls, impervious and easy to keep clean
• roof and loft floors made of dust proof sheet material and easy to clean
• ventilation - clean air and avoid condensation
• artificial lighting - shatterproof and waterproof, good visibility

Question 8

sufficient potable water must be available in milking area for

Answer 8

• hand washing
• udder and teat washing
• rinsing and cleaning equipment

Question 9

how often should inner surfaces of processing equipment and piping be cleaned

Answer 9

once a day

Question 10

what should equipment and piping be made of

Answer 10

stainless steel

Question 11

automated clean in place systems

Answer 11

• incorporated into equipment
• solvents run through the system and then flushed clean

Question 12

sequence of utensils and equipment cleaning

Answer 12

• pre-rinsing
• alkaline cleaning
• rinsing
• disinfection
• rinsing

Question 13

why is cleaning of teats before milking important

Answer 13

• remove visible soiling
• remove bacteria that may contaminate milk

Question 14

what can reduce the count of bacteria in milk

Answer 14

clipping of hair around udder, flanks, tail

Question 15

what is the link between udder and leg hygiene scores of lactating dairy cows vs mastitis

Answer 15

dirty body –> mastitis –> milk contamination (poor milk hygiene)

Question 16

what is the critical control point (HACCP) in milk industry

Answer 16

milking step

Question 17

what may be the singular most cause of milk contamination

Answer 17

mastitis

Question 18

5D for milk hygiene

Answer 18

• distorted milk
• drug residues in milk
• devastated animal
• diseased
• discharges

Question 19

what are some sources of contamination in milk after it leaves the udder

Answer 19

• bucket, pail, cans, bulk tanks

Question 20

hygienic milking

Answer 20

• personnel and operator hygiene
• equipment cleaning
• milking environment
• teats, udder, and adjacent parts must be clean

Question 21

what to do before milking to improve milk hygiene

Answer 21

• fore milking - check milk for physical, chemical, and organoleptic abnormalities
• odor, consistency, color of milk
• check udder for inflammation - swollen, hot, painful

Question 22

what to do after milking to improve milk hygiene

Answer 22

• dipping teat in iodine

Question 23

8 step by step milking procedure

Answer 23

1. observation, sort 5D cows
2. fore stripping, udder checking, sort 5D cows
3. wash and dry teat and udder
4. attaching milking unit
5. adjusting milking unit
6. end of milking - avoid overmilking
7. milking unit removal
8. disinfection

Question 24

what is the most devastating problem to dairy industry

Answer 24

mastitis

Question 25

environmental contributions to mastitis

Answer 25

- bedding, soil, fecal material - E coli, Klebsiella pneumoniae, K oxytoca, Enterobacter aerogenes

Question 26

contagious contributions to mastitis

Answer 26

- transmitted by contact, using the same machine without cleaning in between - Mycoplasma bovis, Staph aureus, Strep agalactiae, Strep dysgalactiae

Question 27

biggest indirect cost of mastitis

Answer 27

production loss

Question 28

how much does the US lose annually due to mastitis

Answer 28

$2 billion

Question 29

water microbes that can contaminate milk

Answer 29

coliforms **pseudomonas** coryneforms alcaligenes

Question 30

feed microbes that can contaminate milk

Answer 30

clostridium **listeria** (found in silage) bacillus lactic acid bacteria

Question 31

soil pathogens that can contaminate milk

Answer 31

**clostridium** **bacillus** pseudomonas mycobacterium yeasts and moulds

Question 32

bedding microbes that can contaminate milk

Answer 32

clostridium bacillus **klebsiella**

Question 33

milking machine microbes that can contaminate milk

Answer 33

micrococcus streptococcus bacillus coliforms

Question 34

outside udder and teats microbes that can contaminate milk

Answer 34

micrococcus staphylococcus enterococcus bacillus

Question 35

most important sources of milk contamination

Answer 35

milking machines and bulk tanks

Question 36

why is mastitis one of the major factors that contribute to milk rejection

Answer 36

it destabilizes the udder ecosystem and milk composition

Question 37

main changes in udder during mastitis

Answer 37

- leaking of ions, proteins, enzymes form blood into milk due to increased permeability (due to inflammation of mammary gland) - invasion of phagocyting cells into milk compartment, basis for somatic cell counts (SCC) in milk to detect and monitor cows for milk hygiene - decrease in synthetic capacity of gland, resulting in decreased concentration of certain milk constituents - affected quarter may produce substances related to inflammatory reaction (acute phase proteins) released during stress

Question 38

good components reduced by mastitis

Answer 38

- total casein (a and B fractions decrease, y fraction increases) - lactose - fat - some whey proteins (a-lactalbumin, B-globulin) - potassium - minerals - Ca, Mg, P

Question 39

bad components increased by mastitis

Answer 39

- bacteria colony counts - somatic cell numbers per mL - enzymes (destroy valuable nutrients in milk) - pH - total whey proteins (bovine serum albumin, immunoglobulins) - sodium - chloride - ions - Cu, Fe, Zn

Question 40

what aspect of milk does mastitis in lactating animals affect

Answer 40

- yield - quality - public health

Question 41

what temperature must milk be cooled to and when

Answer 41

- 4 C - immediately and across entire supply chain until consumption

Question 42

exceptions to 4C temperature

Answer 42

- milk pasteurization or fermentation of cheese and yogurt require temperature higher than 4 C

Question 43

what can grow in refrigerated milk storage (at 4C)

Answer 43

- psychrotrophs - pseudomonas - flavobacterium - alcaligenes - **listeria monocytogenes** - yersinia enterocolitica - some coliforms - bacillus spp

Question 44

what makes milk an excellent medium for microbial growth

Answer 44

- high water activity - moderate pH (6.4-6.6) - high nutrient content

Question 45

on site milk testing to avoid contaminated milk shipment

Answer 45

- temperature of milk must be < 4C - pH must be 6.5-6.7 - organoleptic abnormalities - color - normal milk is whitish - odor - should not have an off odor - taste - normal milk is pleasantly sweet - consistency - normal milk is liquid but not watery - negative to drug residues by lateral flow assay