Dairy Flashcards
five breeds of dairy?
Holstein, Jersey, Brown Swiss, Ayrshire, and Guernsey
Holstein weight
1500 lbs
Holstein orgin
Netherlands
Holstein characteristics
most common dairy, highest milk production, black and white
largest dairy breed?
Holstein
Jersey weight
800-1200 lbs
Jersey orgin
Isle of Jersey in the English Channel
Jersey characteristics
light to dark brown, docile, high butterfat milk component, adaptable
smallest dairy breed?
Jersey
Brown Swiss weight
1300 lbs
Brown Swiss orgin
Switzerland
Brown Swiss characteristics
oldest of dairy breeds, very docile, light to dark brown, nearly grey, desirable fat to protein ratio
Ayrshire weight
1200 lbs
Ayrshire orgin
Switzerland
Ayrshire characteristics
red and white, highly adaptable, hardy, excel in udder conformation
Guernsey weight
1200 lbs
Guernsey orgin
Isle of Guernsey
Guernsey characteristics
white and fawn to deep red, “Golden Goodness” (carotene rich milk), good for cheese production
calving interval
animals must get pregnant and have a calf to start milking
order of events before first milking?
parturition, rebreeding, gestation, dry, parturition
when do calves get weaned
6-8 weeks
what do calves eat when they’re weaned
solids, no more milk replacer
when do cows have their first calving?
24 months
how many months before next calving after first?
12 months
when do we rebreed cows?
80 days
how long is cow pregnancy
285 days
how long is lactation
305 days
how long is dry off
2 months/60 days
what two things happen during dry off?
involution and mammary development
DIM
days in milk (lactating)
when does peak of lactation happen?
50-60 days
three types of lactation?
early, mid, and late lactation
when does late lactation begin?
175-180 days
when does late lactation end?
305 days
what are mammary glands?
modified sweat glands
who has mammary glands
cows, mares, sow, ewe, cat, dog, deer, elephant, whale, giraffe
parenchyma
tissue where milk is produced
epithelial cells
milk synthesis and secretion
lumen
collect milk and water
myoepithelial cells
milk ejection
capillary system
supply milk components
epithelial cells are located where
on the walls of the alveoli
alveolis make what
lobes
each alveoli have their own what
duct
the ducts/duct system connect to what
gland cistern
the gland cistern connects to what
teat cistern
streak canne
teat opening
capillary system is made up of what
veins and arteries
what hormone is associated with milk let down?
oxytocin
what is milk let down?
cows allowing their milk to “be milked”
causes of milk let down
sound of milking machine, sight of calf, touch of skin
what determines grades of milk?
somatic cell count (SCC), bacterial count
fluid or manufacturing milk
Grade A
manufacturing only milk
Grade B
SCC <100,000, <1,000,000 bacteria/mL
Grade A
SCC >250,000, >1,000,000 bacteria/mL
Grade B
how many western dairy coops?
21
how many southern central dairy coops?
11
how many southern atlantic dairy coops?
10
how many west northern central dairy coops?
49
how many east northern central dairy coops?
47
how many northern atlantic dairy coops?
62
pasteurization
sterilization/heating/cooling of milk
temperatures of pasteurization?
4 C, 72 C, 4 C
homogenization
breaking down fat globules into smaller ones
what does homogenization prevent?
milk seperation
percent of water in milk?
87.7%
percent of fat in milk?
3.5-4%
percent of protein in milk?
3.2%
percent of lactose in milk?
4.8%
percent of ash/minerals in milk?
0.7%
what is the only carbohydrate in milk?
lactose
mastitis
swelling of udders
symptoms of mastitis?
inflammation, redness, soreness, blood in milk, high bacteria count
where does mastitis occur
teat canal
why is there blood in milk if a cow has mastitis?
immune cells come from blood stream into lumen to try and kill bacteria
clinical mastitis
with symptom
subclinical mastitis
without symptom
how can you diagnose mastitis?
visual, pH, electrical conductivity, bulk tank SCC, culture testing, electronic SC counters, California Mastitis Test (CMT)
T/F a decrease in conductivity means a cow is positive for mastitis?
false
California Mastitis Test
highly sensitive to the presence of somatic cells in milk
how do you perform CMT?
collect milk from first stream, combine with reagent, swirl, and read
how do you treat mastitis?
antibiotics
if a cow is positive on a CMT, what are the results?
thick and/or bright purple color change
products of dairy
fluid milk, cheese, frozen desserts, butter, dry milk
products of fluid milk
low fat, skim, half and half, heavy cream, whipping cream
T/F fluid milk is homogenized
true
how do you make cheese?
remove the whey
what is the whey?
liquid portion of milk
milk proteins
whey and caseins
rennet
helps create cheese
where was rennet originally extracted from?
abomasum of a newborn
what is butter
the fat in the milk
T/F butter has a higher concentrate of fat
true
fat into water
cream
water into fat
butter
bacteria in yogurt
streptococcus lactus
what is obtained after the fermentation of milk
yogurt
Dairy Herd Improvement Association (DHIA)
a record system. huge database for changes over time for dairy and dairy selection
T/F we have tried to genetically modify dairy a lot to get better genes
false
sire summary
detailed information catalog of sire’s values and genetic potential
sexing/sorting semen
choosing semen that are already sorted between XX and XY
T/F all ovums have X chromosomes
true
in males, how many are X chromosomes and how many are Y’s?
50% and 50%
