Dairy Cow Week 5 Study Questions Flashcards
What are the four major components of milk?
water, fat, protein, lactose
What is the “Dairy Matrix”?
the physical structure of a dairy product, there is nutrients we understand and nutrients we do not know about. This is a product of the natural world and can not be made in the lab.
Define homogenization
heat milk to 145 degrees F for 30 min to kill bacteria
Define pasteurization
mechanical mixing so milk fat globs small and even
Why is Vitamin D added to milk?
increase calcium absorption to prevent rickets
What are the risks associated with drinking raw milk?
it is not pasteurized so it may contain dangerous bacteria
What is a typical milk fat percentage for dairy cows?
3.9%
Does the milk of a fur seal have more or less fat than the milk of a dairy cow?
MORE
What are two types of milk proteins?
caseins and whey
What is lactose?
milk sugar
What are the main ingredients in dairy cow diets?
corn silage, alfalfa, grain, and protein supplements (TMR)
What are the three layers of digesta inside the ruminant stomach?
gas, fiber mat, fluid pool
What is rumination? What can rumination collars be used for?
-regurgitation of already chewed food
-collars can detect the amount of time a cow ruminates each day
What role do bacteria, protozoa, and fungi play inside the rumen?
organisms in the rumen that assist with digestion
What are the primary energy end products of digestion in the rumen?
VFA products, glucose, adipose, and protein
Where does the methane produced in the rumen go?
in the rumen or in manure (atmosphere)
Give some examples of what the dairy industry can do to reduce enteric methane production.
-Take manure from the cows and capture methane to sell
-Biogas generation from manure captures and uses methane that would have gone into the atmosphere otherwise
What can the dairy industry do to reduce the amount of methane coming from manure?
DIET: Cow is making more acetate → producing more methane
-Feed substances/chemicals that kill off bacteria that produce methane
-Having efficient cows → having less cows
–>Get cows that make a lot of milk so you need less cows
What are the molecular building blocks of milk?
water, fatty acids and glycerol, amino acids, and glucose
What is the standard lactation length?
305 days
When does peak lactation occur?
2 months
What is persistency?
a consistent decline in milk production
Are first lactation or fourth lactation cows more persistent?
first lactation
What is negative energy balance?
energy expenditure exceeds intake
What is Body Conditon Score (BCS)? What are the expectations for BCS loss and gain during lactation?
measures and monitors body condition
–> lose some weight after calving but not too much