Dairy Flashcards
What is the leading dairy breed?
Holstein
What percentage of fluid milk is produced from cows?
> 90%
What has happened to cow populations in the United States over time?
movement of cows from one region to another due to legislative and environmental laws
What 6 states are the majority of milk produced in?
California, Wisconsin, Idaho, New York, Pennsylvania, and Texas
What is happening to small herds? Why?
they are disappearing; Mergers and acquisitions are occurring so less and less people are within the infrastructure/industry
What percentage of dairy cow products are fluid milk?
45%
What is done to fluid milk?
it is homogenized
What does homogenized mean?
break down fat
What are the kinds of fluid milk products?
low fat, skim, half and half, whipping cream
What is happening to dairy fluid milk consumption? Why?
it is declining because of milk substitutes, the increase of vegans, and intolerance to it
What percentage of dairy cow products are fermented/frozen?
55%
Why is milk pasteurized?
to get rid of bacteria
What are the kinds of fermented milk products?
cheese, butter, yogurt
What are the kinds of frozen milk products?
yogurts, ice milk, ice cream
How many cheese varieties are there?
> 500
How is pasteurization done?
high temp (160 F) for short time (15s) so they don’t denature proteins
Why are enzymes added during the cheese making process?
so that it coagulates and form curds
Why is cheese ripened?
to age the product to increase flavor and value
What can whey be used for?
a protein source for animals
What is happening to cheese consumption?
growing so cheese production is growing
What is the leading country in cheese production?
France
As ____ in cheese increases, the ____ increases.
total fat; energy
What is Lactose?
sugar
What bacteria is used for yogurt production?
Streptococcus lactis
What is the milk fat % for humans?
3.7
What is the milk fat % for cows?
4.0
What is the milk fat % for mares?
1.3
What is the milk fat % for sows?
5.3
What is the milk fat % for dogs?
8.3
What is the milk fat % for sheep?
5.4
What is the milk fat % for goats?
4.1
How many pounds do Holstein cows produce in a year? How many days is that?
24,000 lbs; 305 days
How many gallons (?) do Holsteins produce per cow?
2,730 gallons
How many gallons (?) do Holsteins produce per day?
8.9 gallons
What is the US breed distribution for Holsteins?
> 90%
What is the US breed distribution for Jersey?
7%
What is the US breed distribution for Guernsey?
<4%
What is the US breed distribution for Brown Swiss?
<3%
What is the US breed distribution for Ayrshire?
<1%
What is the US breed distribution for Milking Shorthorn?
little to none
Why are the majority of cows in the US Holstein?
they outperform and do well under temperate environments
How many pounds of milk per lactation do dairy cows in the US produce on average?
over 21,000 lbs
At what age are the first calves had on average?
25 months
How long is the drying period on average?
58-60 days
How often are calves had on average?
every 13.2 months
How long is a dairy cow’s productive life on average?
3-4 years, short; turnover with Holsteins is higher because they produce a higher content so they have a short production life
What are the dairy cow breeds?
Ayrshire, Brown Swiss, Guernsey, Holstein, and Jersey
What are the milk grades?
Grade A, Grade B, and Grade C
What is Grade A milk?
milk sold for consumption
What is Grade B or C milk?
lower quality milk, used for other products like cheese and butter; cannot be sold for consumption
What is the somatic cell count (SCC) of Grade A milk?
lower
What is the somatic cell count (SCC) of Grade B or C milk?
higher
What is pasteurization?
applying heat up to 15 seconds to kill bacteria
What is another term for pasteurization done on milk?
high temp. short time pasteurization or flash pasteurization
How is pasteurization done in Celsius?
starts at 4 C, heated to 72 C, cooled to 4 C
What does pasteurization result in?
increased shelf life
What is ultra heat treatment?
milk heated to 280 F for 2 seconds
What is the result of ultra heat treatment?
increased shelf life, milk lasts up to 6 months
When is homogenization done?
after pasteurization
What is the purpose of homogenization?
break down fat molecules so it resists separation; done so milk doesn’t separate
What is the result of homogenization?
filtering out fat -> 2% milk, whole fat milk, etc.
What is milk composed of?
water, lactose, fat, casein, minerals (Ca and P), albumin
What is lactose?
a carbohydrate
What is casein?
a protein
What is albumin?
a protein
Function of the alveolus?
where milk is produced
What makes up the lobe?
alveolus, terminal ductule, connective tissue septa, intra lobular connective tissue, lobule
Where does milk go once it is produced?
mammary ducts
Where is milk stored after it is produced?
gland cistern
What is the function of the cricoid fold?
separate the cistern
What is the function of the Furstenberg’s rosette?
prevent bacteria invasion and allows milk to go through streak canal
When does the mammary gland begin to develop?
during puberty but increases in size when animal is pregnant
What hormones are increased during pregnancy?
progesterone and prolactin
What does prolactin do?
helps with the development of alveoli and udder, regulates production of milk
What happens to hormones when a cow is stimulated?
dopamine in the brain is blocked, prolactin increases, and release of oxytocin in posterior pituitary gland
What is the function of oxytocin?
causes the muscles to compress and allow milk to go down
What contracts and allows milk to come out?
myoepithelial cells
How long does it take a cow to fill up with milk?
6 hours
What causes oxytocin to be produced in a cow?
stimulation by a human touching the udder’s skin, sight of a calf, or the sound of a milking machine
What is mastitis?
infection of the mammary gland
How much of the udder is affected when a cow has mastitis?
it can be present in only one quarter of the teets and not the rest
What are the two types of mastitis?
clinical and subclinical
What is clinical mastitis?
can see the symptoms
What is subclinical mastitis?
cannot see the symptoms
if present, what are the symptoms of mastitis?
udder: swelling, redness, soreness
milk: blood, flakes, clots, watery
How is subclinical mastitis detected?
laboratory methods such as bacterial growth or cell count
Is the lactation cycle the same for all species?
no, it varies species to species
What is the same for the lactation cycle for all species?
it reaches a peak and then comes down
What happens once a cow is wheened?
milk production stops till the next calf
How long after calving does breeding take place?
60-90 days
When does the drying period occur?
before calving to allow for rejuvination
What are the types of milking parlors in order of efficiency?
Bali style, Swingover, Herringbone, Rotary
How many cows an hour go through Bali style?
50
How many cows an hour go through Swingover style?
60
How many cows an hour go through Herringbone style?
75
How many cows an hour go through Rotary style?
250
What is the most effective milking parlor style?
rotary but it is very expensive to install
What is a sire summary?
allows you to order semen from a particular bull and this use the semen for dairy
What are sire summaries developed by?
AI companies
What is PTA?
predicted transmuting ability
What does Rel. tell?
reliability; tells the relationship between predicted merit and actual merit
Are more heifers or steers wanted for beef cows?
Steers because they put on more weight
What is the purpose of sexing semen?
to preselect the sex of the offspring
How is semen sexed?
flow cytometry; fluorescent dye used and then measures DNA content of sperm cells to sort it
What does bST stand for?
bovine Somatotropin
What is bST also called?
bovine Growth Hormone (bGH)
What is bST?
a naturally occurring hormone in cows, major regulator of milk production
What percent of cows receive bST?
17.2%
What are the 2 basic external effects of bST?
increase of 6-8% feed intake and 10-20% milk production
What is the brand name of bST?
Posilac
What are the internal effects of bST?
increase metabolic rate and increase lipolysis
What happens when an animal injected with bST gets adequate nutrition?
increase of IGF-I and thus an increase in milk
What happens when an animal injected with bST gets inadequate nutrition?
no change in IGF-I or milk
What is IGF-I?
insulin-like growth factor 1, a growth hormone
Does bST have an effect on milk composition?
no detectable difference
Does bST have an effect on mastitis?
yes, there is a slight increase
What is rBST?
recombinant BST
What is misleading about “this product does not contain rBST claims?
it should be accompanied by “no difference has been shown between milk derived from rbST-supplemented (or treated) cows and non-supplemented cows”
What is misleading about “this product does not contain rBST claims?
it should be accompanied by “no difference has been shown between milk derived from rbST-supplemented (or treated) cows and non-supplemented cows”
What lead to the ultimate success of the dairy industry?
Record system, limited number of traits selected, and adaption of technology
Why did limited number of traits selected lead to success of the dairy industry?
milk production is really the only selected trait (compared to beef cattle which are select for many)
How did adaption of technology lead to success of the dairy industry?
- AI (can use 1 or few bulls to change population)
- Environmental control to optimize environment to maximize production
How is dairy cow environment controlled to optimize the environment and maximize production?
health programs, nutrition, facilities, and equipment
What is the record system used for dairy cows?
Dairy Herd Improvement Association
