ANSC Dairy

Adding vitamin D to milk is an example of

fortification

Reduced-fat milk has approximately

2% fat

In the last 10 years, the number of dairy farms has increased

false

Whole milk fat percentage

3.25%

What percentage of water does milk contain?

87%

In the last 10 years, milk production has increased

true

Subclinical mastitis

milk appears normal but has a high somatic cell count

What are the top two milk producers in the US?

California and Wisconsin

Intensive farming

high inputs and high milk yield

Milk from jersey cows produces the most

cheese

What percentage of milk is minerals?

.7 %

How much of the world’s milk comes from cows?

91%

Other dairy species

• goats

• sheep

• water buffalo

• reindeer

• camels

• horses

Dairy cattle are efficient because

• convert non-edible feed to food

• produces milk, calf for meat, and meat

• use manure as fertilizer

• erosion control

Low input farming

low production costs but less milk

Subsistence farming

low production; family source of food and income

Highest milk per cow production (state)?

Michigan

No fat (fat free) milk has

<.5% fat

Milk processing

• heating to kill microbes

• Homogenization

• Fortification

Pasteurization

heat milk at 71.1 C (161 F) for 15-20 seconds

UHT (ultra high temp)

heat milk at 135 C (275 F) for 1 second

Homogenization

breaking of fat globules so milk doesn’t rise

Fortification

addition of nutrients to milk (Vitamin D and A)

Milk quality control

• antibiotic residue

• somatic cell count

• temperature

• water

• bacteria count

What percent of milk is grade A?

95%

What grade milk is not suitable for fluid?

B

What causes B grade milk?

location of milk house or well location

Percentage of total feed cost/cow

45%

Keys to profitability

• minimize feed cost

• maximize feed efficiency

• improve reproductive efficiency

• make genetic progress

• minimize health problems

• raise calves successfully

• maintain good health records

Prediction transmitting ability

an estimate of genetic superiority or inferiority that a bull or cow will transmit to their offspring for a given trait

When are cows bred?

<100 DIM (Days in milk)

Dry off period

40-70 days

Lactation period

typically 305-365 days

gestation period

279-283 days

Open period (not pregnant)

85-120 days

Transition period

3 weeks prior to and 3 weeks following calving

Problem with transition period

it is a challenging period with most infectious diseases and metabolic disorders occurring at this time

Advantages of AI in dairy

• superior genetics at low cost

• avoid coast, care, and danger of keeping bulls of farm

• disease control

• easier record keeping

• calving easy

Breeds used for dairy

• Ayrshire

• Brown Swiss

• Guernsey

• Holstein

• Jersey

• Milking shorthorn

Holstein characteristics

• high milk production

• large body size

Mammary gland anatomy

• 1 udder has 4 mammary glands

  • each is independent

• Each quarter has millions of alveoli connected by ducts that drain into the udder cistern

• when milking 60% of milk is stored in the alveoli, 20% in the ducts, and 20% in the cistern

Milk ejection reflex

sight of calf/sound of milking machine —> oxytocin —> milk “let-down”

Mastitis causes

Infection (transmitted through hands, cloths, and machines) or trauma

Clinical mastitis

abnormal milk (clots and flakes)

Acute mastitis

causes cow to become sick (bloody watery milk)

Mastitis control

• cleanliness and sanitation

• proper milking

• antibiotic treatment at dry-off

• teat dipping

• culling

Mastitis tests

• California mastitis test

• Strip cup

California mastitis test

• look for subclinical mastitis

• estimates somatic cell count based on gelling detergent

Strip cup

• Look for clinical mastitis

• screen filter for abnormal milk

Wet calf

receiving milk

Freemartin

female born twin to a male, which is usually infertile because negative effects pf male on reproductive development in utero

Weaning age

6-8 weeks

Colostrum

• first milk given to calf

• single most important factor for calf health and survival

• “Gatekeeper” for growth and future productivity

Goal for colostrum management

get colostral antibodies to intestine before environmental bacteria get there

How to measure quality of colostrum

with colostrometer of refractometer

Milk replacer nutrition

• 15-20% fat

• 20-28% protein

When is starter feed introduced to calves?

within the first 1-2 weeks

Purpose of starter feed?

develop rumen of the calf

How to move a cow?

go into flight zone

Walking with cows

slows them down

Walking opposite of cows

speeds them up

Housing systems

• confinement

• loose housing

• grazing

Tie stall housing

• confinement

• labor inefficient

• high cost

• individual attention

Free stall housing

• loose

• higher labor efficiency

• moderate cost

• mastitis risks

Compost barns

• loose

• excellent cow comfort and dry surface

Grazing

• low (no) cost

• cows loose energy walking

• mastitis risks

What is the most important category on a PDCA scorecard (accounts for 40%)

mammary system (udder)

Class I milk

used for fluid milk

Class II milk

used for soft dairy products (cottage cheese, ice cream, yogurt)

Class III milk

used for hard cheese

Class IV milk

used for butter

Freshening period

when a cow has had a calf and is beginning to lactate

What is responsible for producing milk in the udder?

alveoli

3 Q’s and a C for colostrum

• Quickly

• Quantity

• Quality

• Cleanliness

Goals for housing

• dry environment

• Avoid drafts and wind

• Move air to avoid humidity build up

• Cow comfort

• Labor efficient

At what stage in the milking process is milk removed from the teats?

expansion phase