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
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
What are the consequences of excessive weight loss for cows?
illness or disease
–> ketosis or fatty liver
What is a “transition cow”?
30 days prepartum to 30 days postpartum
What are the two worst days in a cow’s life?
the day she calves and the day you dry her off
What percentage of the herd will die on the farm each year? What period is the cow at the greatest risk?
5%
–> first month of lactation
What is milk fever? What are the symptoms of milk fever?
the cow lactates abruptly and drains calcium
– cow will become weak, fall down, and not get back up
How is milk fever treated?
infuse calcium
What is a “negative DCAD diet” and how does a negative DCAD diet prevent milk fever?
control the sensitivity to parathyroid hormone
Why do cows get fatty liver postpartum?
cows lose weight postpartum and fat moves into the liver. The fat forms in the liver and she is unable to get it out.
How do you prevent fatty liver postpartum?
diet, keep on weight postpartum
What causes ketosis in the postpartum cow? What are some common symptoms of ketosis?
elevated BHB in the blood
–> the cow feels sick and will not eat
What are your options for testing a cow for ketosis?
test urine, blood, or milk
How do you treat a cow with ketosis?
propylene glycol
What is the difference between contagious and environmental mastitis pathogens?
contagious is transmitted during milking
–> (passed from cow to cow)
environmental is transmitted through the environment the cow is in
–> (what they touch)
How might you prevent contagious compared with environmental mastitis?
contagious: parlor hygiene, machine function, post dip.
environmental: clean cow stalls, clean everything, udder prep
both: dry cow treatment
What is the difference between clinical and subclinical mastitis?
Clinical – symptoms shown
–> clotted milk, swollen udder, loss of appetite, fever
Subclinical – no symptoms shown
How do you treat mastitis? Can you sell milk from antibiotic treated cows?
-antibiotics (DUMP MILK)
-heal on her own
-sell her
What is milk somatic cell count (SCC) and what does it tell you about mammary infections?
SCC = come from the immune system to fight infection
–> cows with mastitis will have high SCC in milk
What is milk quality? How does SCC affect milk quality, taste and shelf life?
is the milk fresh, flavor, shelf life
–> high SCC affects flavor and shelf life (worse and less)
Are there antibiotic resistant bacteria on dairy farms?
YES
What’s the best way to prevent antibiotic resistance on dairy farms?
use alternatives to antibiotics when possible
What would be a typical incidence of fatty liver, milk fever, ketosis, and mastitis on farm?
-fatty liver (none)
-milk fever (none)
-ketosis (<10%)
-mastitis (<2% of cows each month)
Be able to define or explain VWP, days open, and calving interval.
-Voluntary Waiting Period (VWP) –> amount of time we wait to breed her
-Days Open is the VWP and breeding time
-The calving interval is the days open, through pregnancy, and dry off
What is uterine involution? How long does it take for the uterus to completely restore normal fertility?
The uterus shrinking down to its normal size
–> 60 days
Name the diseases that affect the postpartum uterus.
retained placenta, metritis, endometritis, subclinical endometritis
metritis –> endometritis –> SCE
What causes metritis?
a uterine infection from environmental bacteria
What type of surface is excellent for cows that are calving?
sand!! VERY CLEAN SAND
How do you treat metritis? How do you treat endometritis or SCE?
Metritis: antibiotics
Endometritis or SCE: NO treatments
What is the difference between cyclic and anovular or anestrus cows?
cyclic –> the cow is cycling, going into estrus
anovular/anestrus –> not cycling
What are the two rules for getting cows pregnant?
rule 1: put semen in the cow
rule 2: cow is not pregnant?.. refer to rule 1
What are some methods of heat detection that could be used for postpartum cows?
Chalk or activity collar
How can an activity or rumination collar be used for heat detection?
Activity increases when she is in heat
What are timed AI (presynch ovsynch) programs?
give cows shots to line up ovulation
What is early embryonic loss? What percentage of cows will have early embryonic loss?
expect 10% of pregnancies to be lost in the first 35-60 days
When (approximate time relative to next calving) do you dry off a cow?
dry right before calving
What are the three steps to dry off a cow?
-milk the cow
-“selective” dry cow treatment (antibiotics)
-Orbeseal (seal teat)
What is “selective” dry cow therapy?
treat cows at dry off with an antibiotic
How many lactations does a typical cow have before she is culled?
3
