Mammary

Question 1

Waht is the heritability of medial suspensory ligament conformation?

Answer 1

0.33

Question 2

How many litres of milk can an East Friesian goat give per lactation?

Answer 2

450l

Question 3

How many litres of milk can a Lacaune sheep give per lactation?

Answer 3

290l

Question 4

What is the record annual milk production for a Californian dairy goat?

Answer 4

> 1200l

Question 5

List 7 physiological factors that affect SCC

Answer 5

DIM, parity, oestrus, nutrition, stress, genetics, daylight

Question 6

What is the heritability of SCC in sheep and goats?

Answer 6

0.1-0.15 in sheep. 0.2-0.25 in goats

Question 7

How is the balance of cells in the milk altered in mastitis?

Answer 7

More neutrophils relative to normal macrophages

Question 8

Which bacteria are the most common agents of subclinical mastitis in small ruminants? Name two species from the group

Answer 8

Coagulase negative staphylococci. E.g. epidermidis, caprae

Question 9

What is the cure rate for subclinical mastitis during the dry period on sheep and goats?

Answer 9

Sheep: 35-67%
Goats: 20-60%

Question 10

Which period of lactation is associated with most new cases of mastitis? Why?

Answer 10

First thrid. Start of machine milking and suckle-to-machine transition.

Question 11

List four main areas of focus for mastitis control programmes

Answer 11

Milking routine, hygeine, drying-off, culling

Question 12

Name the two main reservoirs for mastitis-causing staph. and strep.

Answer 12

Mastitic udders and skin

Question 13

What is the frequency of environmental mastitis compared to cattle? What implications does this have for teat dipping?

Answer 13

Much less frequent. Pre-dipping is less important and has less evidence supporting it, but is still recommended

Question 14

What evidence is there to support the use of post-milking teat dipping?

Answer 14

It reduces SCCs and reduces new infections by 30-40%

Question 15

Which animals should be milked first?

Answer 15

Clean, young and recently in milk animals

Question 16

List three milking routine risk factors for hyperkeratosis

Answer 16

Overmilking, vigorous stripping, claw removal under vacuum

Question 17

Is there any evidence for/against abrupt vs gradual dry off?

Answer 17

No evidence either way.

Question 18

What effect do intramammary antibitoics have on the dry period sub-clinical mastitis cure rate?

Answer 18

Sheep: increases from 65% to 96%
Goats: increases from 50% to 93%

Question 19

What threshold has been proposed for culling goats based on SCC (in mycoplasam free herds)

Answer 19

more than one SCC >2 million

Question 20

In what circumstances are teat sealants valuable?

Answer 20

Where environmental mastitis is common

Question 21

What is the Vimco mastitis vaccine targetted against?

Answer 21

Staphylococcus aureus expressing biofilm components

Question 22

One study in Greece showed what reduction in mastitis cases with Vimco

Answer 22

44% reduction in clincial cases
33% reduction in subclinical cases

Question 23

What are the EU limits on bulk milk tank bacterial counts for small ruminants?

Answer 23

1.5million cfu/ml if heat treated
500,000 cfu/ml if not heat treated

Question 24

List 4 sources of high bulk milk tank bacteria counts

Answer 24

mastitis, dirty udders, dirty equipment, poor milk cooling

Question 25

What does a high preincubation bulk milk count suggest?

Answer 25

Equipment or milk cooling problems

Question 26

What does a high lab-pasteurised bulk milk count suggest?

Answer 26

Biofilm formation in equipment, or dirty udders

Question 27

What do high coliform counts suggest?

Answer 27

Very dirty udders or dirty equipment

Question 28

What prevalence of intramammary infections is suggested for sheep's milk bulk tank SCCs of: 1million 500,000 250,000

Answer 28

35% 23% 16%

Question 29

What prevalence of intramammary infections has been suggested for goat's milk bulk tank SCCs of: 1.5million 750,000

Answer 29

50% 30%

Question 30

What iSCC thresholds have been proposed for one-off iSCCs in sheep?

Answer 30

>1mil = infected 500k-1mil = suspicious <500k = clean

Question 31

What thresholds have been suggested for serial iSCCs in sheep and goats?

Answer 31

Lower threshold: 250k in sheep, 750k in goats Upper threshold: 800k in sheep, 1.5mil in goats Two+ values over upper threshold = mastitis All under lower threshold = clean Anything else = intermediate

Question 32

Describe how to perform a Caliofornia Mastitis test

Answer 32

Add one teaspoon of reagaent and one of milk to each paddle. Swirl for 10-30s and then tip out. Score 1: starts to climb the sides when swirling but does not gel Score 2: Starts to gel but still purs out Score 3: Single mass of gel tips out together

Question 33

Describe one way to perform a milk quality crisis intervention.

Answer 33

Calculate individual animal SCC and bacterial controbutions to the bulk tnak by multiplying concentration by yield. Removing the worst 10% offenders from contributing to the tank can reduce bulk SCC by 99%

Question 34

List the range of syndromes seen with contagious agalactia (6)

Answer 34

Agalactia, fever, arthritis, keratoconjunctivitis, pneumonia, septicaemia

Question 35

List the 4 (sub)species potentially responsible for contagious agalactia.

Answer 35

M. agalactiae M. mycoides capri (Mmc) M. capricolum capricolum (Mcc) M. putrefasciens

Question 36

By what routes is contagious agalactia shed and for how long?

Answer 36

Shed in all bodily fluids for months post infection

Question 37

What is the incubation period of contagious agalactia?

Answer 37

5-7 days

Question 38

Describe the clinical course of contagious agalactia mastitis

Answer 38

Over the course of three days milk will progress from watery, to thick and lumpy, to completely absent.

Question 39

What mortality rates are assocaited with contagious agalactia

Answer 39

Up to 100% in youngstock 0-50% in adults depending on strain, host and endemicity

Question 40

What is the sensitivity and specificity for Mycoplasma agalactiae serology in unvaccinated animals?

Answer 40

Se: 75-85%, Sp: 99%

Question 41

Describe the mammary histopathology in contagious agalactiae

Answer 41

Interstitial inflammation with mononuclear leukocytes around acini and ducts, and within ducts alongside desquamated epithelial cells.

Question 42

Is antibiotic treatment fo contagious agalactia successful?

Answer 42

Rarely and can induce carrier status. (Range of tissues infected, plus biofilm formation, makes antibiotic choice and interpretation of resistance tests impossible)

Question 43

How can contagious agalactia be controlled?

Answer 43

Test and separate/cull or endemic management with partially effective inactivated vaccines.

Question 44

Name two factors associated with precocious udder

Answer 44

Selection for high mlk yield. Production of PTHrP

Question 45

List 9 zoonotic pathogens of raw milk

Answer 45

C. jejuni STEC Listeria Salmonella Staph aureus Coxiella Brucella Tuberculosis TBEV

Question 46

By what cellular mechanism is small ruminant milk produced?

Answer 46

Apocrine secretion

Question 47

Which stain is used for direct microscopy of milk somatic cells?

Answer 47

Pyronin Y-methyl green

Question 48

Deficiencies of which micronutrients are associated with mastitis?

Answer 48

Vitamins A & E, Selenium

Question 48

List the four methods of somatic cell counting. What is counted in each?

Answer 48

Direct micrsocopy: Cells Coulter counter: Particles Fossomatic and DeLaval: DNA