Mastitis Flashcards
Goat, sheep, and cow milk are not the same. Of the 3 which species has the lowest % solids, % protein, fat, and ash?
cow
Goat, sheep, and cow milk are not the same. Of the 3 which species has the highest % solids, % protein, fat, and ash?
sheep
what is the clinical application of the fact that sheep and goats have higher solids, protein, fat, and ash content of their milk than cows do?
cannot use an all round milk replacer for lambs and goats because they’ll only be getting 1/3 of their requirements.
Milk in goats is produced via _____ secretion, which is different from cows that secrete milk via _____ secretion.
goats - apocrine
cows (and sheep)- merocrine
what is the clinical significance of goats producing milk via aprocrine secretion?
during milk secretion, a portion of the cell membrane is pinched off and can contain DNA/RNA. This DNA/RNA can be counted in the SCC, which increases the overall SCC.
In cases of cows and sheep with merocrine secretion, the milk products are secreted from the cells via exocytosis.
what is the legal limit of somatic cells in goat milk?
1,000,000 cells/mL
what is the predominate cell type of goat milk that also affects the SCC?
neutrophils (50-70%)
in cow milk, there are only 5-20% and in sheep only 15-40%.
what are 2 DNA-specific counting methods to measure SCC?
- fossomatic electronic cell counter (must be calibrated to goat milk)
- direct microscopic counts using DNA-specific stain (pyonin green stain). better accuracy, but time consuming
what are the 8 factors that affect somatic cell counts?
- neutrophils
- lactation number
- stage of lactation
- estrus
- time of day
- lentivirus infection
- management changes
- infection
How does stage of lactation influence SCC?
In goats, sheep, and cows, SCC increase as days in milk (DIM) increases, especially towards the end of lactation. This is because of the dilution effect.
How does parity and number of lactations affect SCC?
SCC increases with each subsequent lactation
T/F: unless a bovine dairy is season, the increase in SCC at the end of lactation has NO effect on the bulk tank SCC.
true
why does estrus increase SCC?
estrogen increases epithelial generation and exfoliation. the increase in epithelial cells increases the SCC.
why is keeping SCC down in the fall so difficult?
- long days in milk
- decreased production
- breeding activity
how does time of day affect SCC in sheep vs goats?
Goats – LOWER SCC in the morning
Sheep – HIGHER SCC in the morning
which viruses increase SCC in cows, sheep, and goats?
lentiviruses (ovine progressive pneumonia, caprine encephalitis arthritis)
T/F: rumen acidosis and other conditions associated with high grain diets do not increase SCC in small ruminants.
false – they do. it seems SRs are more sensitive to stress compared to cattle.
T/F: vaccination increases SCC for up to 21 days in goats.
false – for 7 days
T/F: handmilked ewes have 1/2 SCC than machine-milked ewes
true
which organisms are MOST commonly isolated from mastitis in small ruminants?
staphylococcus spp. (staph aureus –> clinical infection, blue bag)
(coagulase negative staphs –> subclinical infections)
In addition to staphs, what other organisms cause mastitis in small ruminants, but less commonly?
- environmental streps (rarely)
- pasteurella (rare in goats)
- coliforms (rare in SRs)
- others – trueperella pyogenes, corynebacterium
T/F: because of variations in SCC ad the many factors affecting SCC, SCCs are not very useful in detecting intramammary infections of small ruminants, especially in goats.
true
what CMT score is considered normal for small ruminants?
trace or 1.
milk scores 2 or 3 should be considered for culture.
Why should udders be palpated prior to breeding?
fibrosis of the udder can occur with mammary infections. this fibrosis will cause reduced milk production and subclinical infections.
if you palpate and see hard areas, you should cull her because she will not have adequate milk yields and may develop mastitis from subclinical infection.
