Lecture #20 ~ Intro to Dairy Science

Dr. Tess Stahl

name some dairy animals

cows, goats, sheep, buffalo, camels

what do dairy animals consume

forage, grains, byproducts

what do dairy animals convert feeds into?

high quality nutritious milk

why did the number of cattle and calves peak in 1979

became more efficient, so needed fewer cows

In the USA, every 1 cow equals ___ people

3.8

Most of the 89 million cows and calves in the US, most are ____

beef cattle

how much does the average producing Holstein make in lbs of milk

24k lbs

if every Holstein makes 24k lbs, it is __ lbs/day/cow

79

why shouldn’t we go back to small farms to produce food and milk?

not possible due to high demand —> the trend is fewer but bigger dairy farms

where are big dairy farms located?

California, Wisconsin, Idaho, Texas, New York

Cows are milked ___x per day

2-3

Where is milk stored until picked up?

bulk tank

what does a bulk tank do?

provide constant temps (below 40 degrees F) and continuous agitation of milk

why is it important to cool milk immediately after milking?

reduce bacterial growth

what do increased bacterial counts in milk do?

reduce shelf life of finished products

what should a properly operating milk cooling system do?

cool milk below 40F by 30 mins after first milking, hold milk between 36-38F, and prevent blend temps from rising above 45F during addition of milk from subsequent milkings

how often is milk picked up by the milk hauler

48 hours

what happens every time a truck driver picks up milk from a farm?

a milk sample is collected before the milk is loaded onto the tanker

where is the milk transported in?

insulated milk tanker

what happens when the tanker arrives to the plant?

the entire tanker is tested for milk temp, quality, bacteria, and drug residue

what is pasteurization

rapidly heating milk to kill bacteria and then quickly cooling it to prevent new bacteria from forming

what are the two common pasteurization methods used?

high-temp short time (72C for 15 sec) and ultra-high temp (138C for 2 sec)

what does homogenization do

prevent cream from separating from the milk (also fortified w/ vit A and D around this time)

what is standardization

adjusting the fat in milk (whole milk, 2%, 1%, skim)

after milk is packaged, where is it sent to?

grocery stores or other processing plants to make cheese, yogurt, etc.

raw milk was implicated in the spread of many diseases, such as:

scarlet fever, typhoid fever, tuberculosis, cholera infantum…

why were diseases caused by raw milk such a deadly threat?

unsanitary production, poor refrigeration, bad transport, contained retail conditions

in general, fluid milk consumption is ____

down

what kind of fluid milk is relatively linear on the graph in terms of sales?

buttermilk, flavored milk, skim, lower fat (second two not rly but kinda)

has the per capita consumption of butter increased or decreased?

stayed constant

has the per capita consumption of cheese increased or decreased?

increased

milk products are ___-dense

nutrient

what does milk supply

numerous nutrients in abundant, high-quality amounts

milk composition varies, based on:

species, breed, feed, lactation

water is ___% water

88

what is milk one the best sources of >?

protein

what does milk contain which makes it a high quallity complete protein

essential amino acids

20 million Americans suffer from ___

osteoporosis

how many cups of low-fat skim milk covers daily reqs?

3

When is it most important to get calcium?

when young

___% of our dietary B12 comes from milk

20

Is it possible to meet the dietary B12 req without some sort of animal product or dietary supplement

No

What does daily dairy include?

Feeding, cleaning, AI, treating, marketing, record keeping, crop producing, management

three types of dairy housing/management

pasture, organic, confinement

examples of confinement housing

free stalls, tie stalls, bedded packs, compost barns, dry lots

describe pasture

lower-input, lower-production, smaller breeds = better grazers, high land requirement, year-round good climate

since what and when has organic farming and labeling becoming greatly unified in the US?

creation of USDA National Organic Program; October 2002

All products sold as “organic” must be produced, handled, and processed according to ___

NOP “Final Rule”

In organic dairies, what are cows/calves fed?

100% organic feed

In organic dairies, what must crops, hay, and pasture be grown without

synthetic fertilizers and pesticides that weren’t approved

In organic dairies, do non-natural feed additives and supplements need o be approved?

yes

In organic dairies, are GMOS allowed?

no!

In organic dairies, land used to grow organic crops must _______

be free of all prohibited materials for at least 3 yrs before first organic harvest

In organic dairies, synthetic milk replacers are ____; calves must be fed _____

prohibited; organic milk/milk replacer

In organic dairies, animals must have access to _____

outdoors (weather permitting)

In organic dairies, animals over ____ months must have access to pasture during ____ season

6; growing

In organic dairies, only ____ healthcare products may be used

approved

In organic dairies, are most healthcare products restricted in how and when they can be used?

yes

In organic dairies, antibiotics are ____

not allowed

In organic dairies, organic animals cannot be fed ____ or ____

any slaughter by-products; urea

In organic dairies, tail docking is ____

prohibited

In organic dairies, procedures like dehorning must be done as as to _______

minimize stress to the animal

In organic dairies, the farmer needs to keep ____ records to verify compliance

sufficient

In organic dairies, how often is the farm inspected and audited?

every year (unannounced)

describe free stalls

most common for larger diaries; sand/sawdust/mattresses; cow comfort; less travel time; controlled environment; more cows on less land

describe tie stalls

cows cares for, fed, and milked individually; flat barn; old dairies; fewer cows; cold climates

describe bedded packs

becoming popular; less overhead cost; increased cow comfort; managed intensively; compost waste and shavings to kill bacteria; higher SCC?

describe dry lot

popular in Cali and arid climates; feed alley and shades; no formal housing; lots scraped and cleaned often

types of milk parlors (places where cow gets milked)

tie stall, side opening, herringbone, parallel, robotic, rotary/carousel

describe tie stall parlor

cows are level with you, milk flows through vacuum, lines

describe side opening milk parlor

cows come individually, much slower, not common

describe herringbone parlor

most common design on dairy farms w/ smaller herds, 45 degree angle = different access point

describe parallel parlor

cows stand parallel to each other, most common type, milk doesn’t begin until all are in stalls, released at once, takes 10 mins

describe rotary parlor

like carousel rides, stalls arranged in a large circle on a platform that rotates slowly; cows can walk in and leave in a round or two; lets cows come to milker

describe stalls

need to be properly bedded; sand is best (most comfy and inorganic), must be deeply bedded and groomed, expensive

what can you put in a stall for comfrt?

sand, rubber mats, mattresses, water beds

why are concrete surfaces important

provides texture and grooving which provides traction and allows water drainage

rubber mats should be in:

feed bunks, alleyways, holding pen, milking parlor

rubber mats function to:

promote feed intake and cow health, and reduce injuries

in hot summer months, alleviating heat stress can help _____

maintain milk production

comfortable temp range for a cow is ___ to ___ F

41-77

rumen is an ____

internal furnace

heat stress can result in…

decreased feed intake, decreased milk production, increased potential for metabolic diseases, decreased repro performance

ways to keep cows cool:

fans, shade, misters, evaporative cooling

where should misters be?

over feed bunk and holding pen, NOT over stalls (set a timer and thermostat)

describe evaporative cooling

water cools the animal, fans dry the water to cause evaporation, as water evaporates it takes energy w/ it, wetting alone may increase humidity and worsen heat stress

describe the Holstein breed

From Netherlands, most popular, over 90% of dairy cows, higdehest milk producers, lowest components, largest breed

describe red and white

Holstein but w/ recessive gene

describe Jersey

originated on isle of jersey, 2nd most popular, highest butterfat and protein production, smallest breed, efficient producers, bulls are superrr aggressive

describe brown swiss

originated in swiss alps, large framed, docile and friendly, adaptable to diff climates, high milk volume w/ ideal fat-to-protein ratio (good for cheese!)

descirbe guernsey

originated on isle guernsey, medium sized, docile and gentle, produces rich and golden milk high in beta carotene, high butterfat and protein content (good for cheese), efficient feed coverter and easy calving

describe ayrshire

originated in scotland, range from dark red to light red w/ white, medium, hardy, adaptable, tend to be more nervous, higher fat and protein (good for yogurt, cheese, ice cream)

describe shorthorn

originated in northeastern england, closely related to shorthorn beef cattle, may be red/red and white/white/roan, medium sized, hardy, long-lived, milk ideal for cheese w/ balanced fat and protein, low somatic cell counts, few health problems