9/4 - Mammary Glands

5

In bovines, there is no effect on milk production until how many months of gestation? This is when mammary cell numbers start to decrease.

No

Do the bovine’s four milk glands and two halves of the udder commonly communicate?

Rear

Do the rear or front quarters of the bovine udder produce more milk?

2

Sheep and goats have how many mammary glands, with two halves and two teats containing a single streak canal?

4

How many quarters in the mammary gland do camels and camelids have? There are 2 halves, mastitis is rare, and milk production is similar to horses.

Alveolar

What epithelial cells in the mammary glands produce milk using nutrients from the blood? 300 mL of blood per second goes to the udder in bovines in peak lactation.

Oxytocin

After stimulation of the mammary gland, what hormone is released to cause myoepithelial cells to contract, ejecting milk from the lobule lumen and relaxing the teat sphincter?

Streak

What canal in the teat has a sphincter and during dry periods can produce a keratin plug for protection against mastitis?

Macrophages

What cells are always present in the udders of bovine, sheep, and goats?

Neutrophils

What cells are present normally in goat udders, but are only present in bovines and sheep if there is infection? WBCs are not typically effective in milk due to lack of glucose and coating of cells with casein and fat.

Lactoferrin

What molecule provides noncellular defense to the udder by binding iron to limit bacterial growth? It is high in milk and 10x higher in colostrum. Cytokines are also present.

Indirect

What type of cell count on milk can be done with CMT, WMT, or conductivity tests to estimate SCCs?

Somatic

In direct counts of what type of cells in milk, should be less than 200 K to be considered excellent? Bulk tank counts uses a commingled sample from the entire herd and has a legal limit on bulk tank milk. The US maximum is 750,000 mL and the EU maximum is 400,000 mL.

30

CMT testing should be read within how many seconds of milking?

Negative

Which CMT score is when the mixture remains liquid, homogenous, and with no evidence of thickening? There should be less than 200,000 SCCs.

Trace

Which CMT score involves slight thickening that forms and is seen best by tipping the paddle back and forth and observing the mixture as it flows over the bottom of the cup? These reactions tend to disappear with continued rotation of the paddle. SCCs will be 150k-500k.

1

Which CMT score refers to weak positives and involves a distinct thickening of the liquid forms, but with no tendency toward gel formation, and may disappear sometimes after over 20 seconds? SCCs will be 400k to 1.5 million.

2

Which CMT score refers to distinct positives and thickens immediately, with a gel formation? The mixture will tend toward the center when swirled. SCCs will be 800k - 5 million.

3

Which CMT score refers to a severe positive and involves gel formation, fried egg surface, and a central peak projecting above the mass even after rotating? SCCs will be over 5 million.

Yes

Can colostrum, late lactation, illness and decrease in milk volume, first stripping of milk, residual milk, and udder trauma cause false positive CMTs?

Culture, PCR

What two tests can be used to identify mastitis agents, test for antimicrobial sensitivity, and for biosecurity/control? Environmental contamination is easy to get when collecting samples for these tests.