Lecture 11: Milk Quality + Mastitis

Concept: What are the components of milk

-whey protein

-casein protein

-crude protein

Concept: How do we measure milk quality?

-how do we test?

-can milk be sold from cows be treated with antibiotics?

-when is milk tested for antibiotics?

-why do we test for freezing point of milk

-taking bacteria count via incubation

-no drug residues can be present

-tested at plant prior or be unloaded into processing

-test to evalulate if additonal water was added to create more volume of product, milk has a lower freezing point than water

Concept: How do we measure milk quality?

-what do we cells do we measure?

-what are somatic cells?

-Leukocytes are a response to?

-Epithelia cells are a response to?

-what are major cells that reduced to bacteria invasion?

-how can somatic cell count affect milk quality?

-what is the standard U.S limit for ssc?

-when is scc typically high

-somatic cell count

-cells produced from the body

-both response to injury or infection

-polymorphonuclear: neutrophils, eosinophils, basophils(little are epithelia cells)

-high scc can make milk taste more bitter and rancid

-want lower scc because it can increase shelf life or product

-750,000 cells/mL

-mastitis, early lactation(usually higher, udder/teat injury, late lactation(making less milk)

-cows milked more regularly have less ssc

Concept: Mastitis

-when is mastitis common?

-how can mastitis affect mammary gland?

-common in after dry off: milk is not getting removed due to teat sealant, milk good medium for bacterial growth

-Calving: immuno-supression, sometimes teats experience edema

-inflammation of somatic cells released to bacteria producing toxins

-toxins can injure alveoli + ducts

-elevated ssc can reduce milk yield + alter milk composition