Midterm

Factors That Effect Milk Composition Produced by the Cow

Breed Stage of Lactation Season Genetics Nutrition - Feeds Disease - Mastitis

Which of the following is a heat detection accuracy error?

Breeding a cow that is not in heat

Cherry picking in a synchronization protocol refers to?

Breeding animals that come into heat before the protocol is complete

Which breed of dairy cattle is known for its good leg conformation

Brown Swiss

What dairy product is made when cream is agressively mixed to breakdown the fat globules causing them to coalesce?

Butter

Pounds of raw milk required to make 1 lb of product

Butter 21.91 Non

Milk is homogenized to keep what milk component from separating?

Butterfat

What US state has the most dairy cows?

California

Detector Animals

Can use bull, steer, cow or freemartin 24-hour detection Reduced heat detection labor Animal must have good feet and legs Costs: animal, housing, feeding Investment in marking system Poor results if hormone injections are not followed Danger of aggressive animals

Which of the following is true about liner slips

Cause milk to impact the teat ends

Whey is a byproduct of the manufacturing of what dairy product?

Cheese

Milk used for fluid consumption is valued at what price?

Class 1

Why the Western Shift?

Climate Less housing facilities Fewer pollution problems (run off) Forage Quality and Availability High Production Potential Lower Cost of Production Transporting products longer distances Following Population Shift Processing facilities

Milkfat

Complex blend of lipids Triglycerides 98% of lipids Mono and Diglycerides, FFA, Phospholipids and Cholesterol Fat and water don't mix Forms globules surrounded by protein Rise to top Provide the young with energy Content is highly variable Species, breeds, stage of lactation Feed, fiber, temperature

HCD- Haploid For Cholesterol Deficiency

Condition first noticed in Germany, cause identified in 2015 Causes non-treatable lethal diarrhea Poor growth and development No causative pathogen Increased calf losses Die 3 weeks to 6 months of age Some survive for more than 2 years All fat reserves are used up including the fat of the spinal cord Indication of disorder of fat metabolism Pedigree analyses revealed common ancestors Maughlin Storm Braedale Goldwyn Chromosome 11 Actual site of mutation has not been identified Of 234 homozygous animals found in genomic databases 80 % were dead Heterozygous carriers have significantly less blood cholesterol

Udder edema

Congestion and fluid accumulation in udder Heifers more prone Exact cause unknown Impaired blood and lymph circulation in the abdomen Drop in blood protein levels due to colostrum production Prepartum nutrition High grain feeding High Sodium and Potassium Treatment / Prevention Pre milking, frequent milking, massage Diuretics and anionic salts

Vacuum Regulator

Controls vacuum in system and at teat ends Prevents vacuum from getting too high by allowing air into system Has filter that requires periodic cleaning

the most common form of mating system used on dairy herds is?

Corrective mating

Accuracy of Selection

Correlation between the phenotype and genotype Is what you see, what you get? (Genetically speaking) Ability to accurately predict the breeding value of an individual Higher heritability improves accuracy of prediction Power in numbers More information on more relatives means higher accuracy Daughters, parents, siblings, half sibs etc. In the animal model the accuracy of the prediction is called reliability

Genetic Information

Council on Dairy Cattle Breeding Summarizes DHIA information Production Components SCC Reproduction Longevity USDA-AIPL US Department of Agriculture - Animal Improvement Performance Laboratory Helps CDCB gather and summarize data Breed Association Type information Final scores Linear Traits NAAB - National Association Animal Breeders Calving ease information

A2 Milk

Cows can produce several variants of beta casein depending on their genetics. The 2 most common variants are A1 and A2 A cow can be A1/A1 - Produce all A1 casein A2/A2 - Produce all A2 casein A1/A2 - Produce a mixture of A1 and A2 Important because A2 beta casein has been shown to cause less bloating and digestive upsets in humans. Not associated with lactose intolerance Same nutritionally Being sold in parts of the US as a healthier alternative?

Voluntary Culling

Culled for traits that make them less desirable or productive. Could stay in the herd. Usually caused by bad genetics. Low milk production (Main Reason) Conformation Temperament Improve genetic progress.

Involuntary Culling

Culled for traits that make them useless. Have to be removed from herd. Usually caused by bad environment. Death Disease Failure to reproduce (Main Reason) Reduces genetic progress. Goal <25% of herd annually Makes room for internal herd growth or more voluntary culling

What vitamin is routinely added to milk to improve calcium absorption?

D

Measures of HD Efficiency

DIM at First Breeding Percent Confirmed on Pregnancy Checks DHIA Percent Observed Heats 24-Day Chart 21 day Breeding Summaries

The organization that maintains production records for over half the cows in the US is know by the letters DHIA. What does DHIA stand for?

Dairy Herd Improvement Association

Genomics works very well in dairy cattle. Which of the following is not a reason for its success with dairy cattle?

Dairy animals are relatively inexpensive.

Which of the following is not an advantage dairy producers have over other livestock producers in making genetic progress in their animals?

Dairy cows live a long time and produce numerous offspring.

BLAD

Defect of Holsteins Autosomal recessive allele Single substitution mutation Descendents of Osborndale Ivanhoe Neutrophils don't leave the blood stream At one point 15% of the AI sires and 8% of the cows were carriers for the gene Clinical signs Calves prone to infections Pneumonia, scours, wounds don't heal Neutrophils build up in the blood Death before 6 months of age

DUMPS

Deficiency of Uridine Monophosphate Synthetase Autosomal embryonic lethal Fetus dies about Day 40 - Abortion Point mutation in DNA that codes for this enzyme Carriers: Happy Herd Beautician Skokie Sensation Ned Enzyme found in all body cells Essential in the manufacture of UMP - important nucleotide

Mating Systems

Define as a system of combining genes of individuals in a population in order to alter the gene distribution Random, Inbreeding, Crossbreeding, Outbreeding, Line Breeding, Positive Assortative, Negative Assortative - Corrective matings Most all dairy cattle mating programs are based on the concept of "corrective matings" Physical faults are identified for each cow A superior bull for these traits is chosen Example: Your cow has wide teat placement and a low foot angle Among the sires you've chosen, mate her to the one with highest PTA for teat placement and foot angle •Mating programs also help control inbreeding

Farm Inspection

Describe in the PMO Who does it? Milk Plant State Department of Agriculture USDA-APHIS Twice yearly inspection of: Cows Equipment Housing Water supply

How do you breed a herd?

Determine the goals for the farm Milk, embryos, bulls for AI, showing Conventional, organic, grazing, home processing etc. What kind of cow do you want? What traits are most important to help you reach your goal? What traits are most needed by your herd? Limit the number Consider indexes Select a group of bulls that are high for the traits you have chosen Purchase just enough semen from these bulls to last for 6-9 months Consider young sires Mate each cow in the herd to one of these bulls Keep breeding program on tract

Cows show better heat when standing on what surface?

Dirt

Coliforms

E. coli, Klebsiella spp., Enterobacter spp., Citrobacter spp. Gram negative In the manure and soil In and on everything Bedding, equipment, water, hides, milkers,etc. Can cause subclinical, clinical, acute and paracute (severe) forms of mastitis When infected, immune system causes white blood cells to destroy the organism. In doing so endotoxins are released causing very severe symptoms and death More prevalent in warm, wet weather

Sizing vacuum pumps

Each Hp on the pump moves about 10 CFM of air 5 HP Pump = 50 CFM As pump gets worn, the CFM it can move goes down Each unit requires 3 CFM to milk Need additional CFM in case of unit fall-offs One fall off may allow up to 35 CFM of air into system Smaller systems add reserve for one fall-off Witter Farm - 4 milking units (4 units x 3 CFM/unit) + 35 for fall-off = 47 CFM pump capacity Requires a 5 Hp pump

Breeding Dairy Cattle

Easier than in most other types of livestock Milk is most important economic trait Large database of information CDCB, USDA-AIPL, DHIA & bull studs 4 million cow records annually in the US Accurate information on individual cows Controversial No two breeders can agree on how to breed Complicated formulas Population genetics is entirely statistics

Important Dates

Edward Jenner developed the small pox vaccine by infecting humans with cow pox virus (1796) By the early 1800's many states made small pox vaccination manditory First cheese plant (1851) Gail Borden received patent for condensed milk (1856) Maine Jersey breeders formed first US breed association - 1860 Pasteurization invented - (1860's) Prevention of TB, Bangs, Diptheria, Scarlet fever Delaval invented the cream separator (1871) New York Milk War (1883) Farm dumped milk to raise price to 3-4 cents/quart Dr. henry Thatcher invented the first glass milk bottle (1884) Before that milk delivered in open pails William Dempster Hoard began publishing Hoard's Dairyman (1885) Babcock developed method to measure butterfat (1890) Commercial pasteurization begins (1895) Milk Homogenizer is patented (1899) Milking machine invented by Alex Giles of Australia (1903) Rural electrification enabled the use of vacuum pumps, machine milking and refrigeration (1920-1930's) First milk cartons used (1950) Bulk tanks used to store milk rather than cans (1960) BST is approved in the US (1993)

Pulsator

Electric or vacuum powered valve Alternates allowing vacuum and air into the pulsation chamber Connected to teat cup by short and long air tubes Controls Pulsation Rate and Ratio Pulsation Rate Pulsations (beats) per minute About 60/minute Pulsation ratio Proportion of time in milk versus rest phase 50:50 to 70:30 Length of rest phase most important Needs 200+ milliseconds Critical part because it controls how cow is milked! Valves do get worn

Which of the following is not a tool which can be used by breeders to geneticallt imporve dairy cattle?

Environment

Why is the heritability of reproductive traits low?

Environment affects reproductive traits much more than genetics.

Environment Mastitis

Environment to cow Incidence increases as the incidence of contagious mastitis decreases Primary habitat of bacterial is in the environment (feces, soil, bedding, water) Mainly due to environmental contact between milkings Sometimes spread at milking due to dirty equipment Organisms from the bedding, stalls, pens, gain entrance through fatigued teat canals after or during milking Coliforms, Environmental Streps and Enironmental Staphs are the main organisms

Somatic Cell Counts - SCC

Epithelial cells and white blood cells Measures the level of udder stress/damage/irritation Individual Cows Under 200,000 /ml uninfected Over 200,000 /ml considered infected Not a measure of actual mastitis infection Do not treat based solely on SCC! Bulk Tank Legal limit 750,000/ml not very stringent 400,000 now defacto limit for most farms Excellent mastitis management tool Easy way to assess the mastitis level in a herd Highest correlation with milk production of any DHIA measure

Improving Heat Detection

Establish HD SOP's Utilize records to anticipate heats Utilize group interactions Detect when cows are not doing anything else The more time spent detecting the better Location, location, location Minimize sore feet Use aids wisely If in doubt, INDUCE Don't take shortcuts

Breeding Value

Estimate of animal's genotype Genetic superiority of inferiority Information is power More measurements on a individual increases accuracy of BV estimate More measurements on relatives increases accuracy of BV estimate Half of breeding value is transmitted to offspring Predicted Transmitting Ability - PTA

Genomic evaluations of dairy animals:

Evaluate the DNA actually received by the animal.

Milk Production Is Primary Trait

Every other trait is minor in comparison Quantitative trait Controlled by a large number of gene pairs Expression affected greatly by the environment of the individual Moderate heritability 0.25 - 0.30 Large database of information aids in calculating BV USDA-AIPL, DHIA & studs 4 million cow records annually in the US Accurate information on individual cows

Genomic Selection Advantages

Expensive progeny testing would not be required. A greater accuracy of predicted genetic merit for young animals. Decision to keep or cull an animal could be made earlier in an animal's life. A shorter generation interval because of heavier use of young, superior males and females. An increased intensity of selection because breeders can use genomic testing to screen a larger group of potentially elite animals. By increasing the accuracy and intensity of selection and shortening the generation interval, the rate of genetic progress for economically important dairy traits can be approximately doubled.

When Should a Cow be Removed From the Herd?

Extremely complex decision Many factors to consider Milk price, cull price, future production Reproductive status, genetic potential Replacement available, fixed & variable costs Easy decision if replacement is unavailable Hold on to her as long as she is covering variable costs and some fixed costs Becomes much more complicated when replacement is available Effects genetic progress and farm profitability for many years to come

Raw Milk Tests

Fat and Protein Somatic Cell Count Standard Plate Count Lab Pasteurized Count Coliform Count Preliminary Incubation Count Antibiotics

Low Milk Fat to Milk Protein Ratio

Fat%/Protein % Usually Holstein milk is 3.7% F and 3.1% P - Ratio = 1.23 Fat inversion Fat lower than protein - ie. 2.9% F and 3.0% P Ratio <1 Indicator of acidosis Caused by low acetate production in rumen which is used for fat synthesis High grain - low fiber diets Decrease acetate Increase propionate

The Pasteurized Milk Ordinance is the set of rules regarding the production of milk in the US. What government agency is responsible for the PMO?

Food and Drug Administration

Which of the following factors is negatively correlated with genetic change per year?

Generation interval

Genetic Gain per Year

Genetic change per year = (√Reliability x Intensity x Genetic Variation) ----------------------- Generation Interval Reliability (Selection Accuracy) = how certain we are about our estimate of an animal's genetic merit (↑) Selection intensity = function of fraction selected (↑) Genetic variance = can't really change Generation interval = time between generations (↓)

The milk producing cells produce lactose from what blood precursor?

Glucose

Lactose Synthesis

Glucose Major precursor Can limit secretion 50% made from propionate Mammary gland uses 60-85% 60-70 of that is used to make lactose Lactose synthetase - Golgi Galactosyltranferase-bound Alpha lactalbumin-soluable Regulatory Lost in secretory vessicles

History of Dairying

Goes back to 6000 to 8000 B.C. in Mesopotamia Domestication of the cow First written records of milking cows - 6000 B.C. 7000 year old clay pots found with butter residue in them Britain and Northern Europe ~ 4,000 to 6,000 BC First to begin milking cattle for human consumption. Found pottery chards that once contained milkfat Scientists, the ability to digest milk was slowly gained some time between 5000-4000 BC by the spread of a genetic mutation called lactase persistence that allowed post-weaned humans to continue to digest milk. Similar events were occurring in North Africa and India Egypt and the Middle East ~3000 B.C. Dairy products such as butter and cheese became an important part of civilization The Egyptians held the cow sacred Isis the goddess of agriculture is depicted as a cow Hathor, was the cow goddess who guarded the fertility of the land Northern India ~ 2000 BC The domesticated cow appears coinciding with the arrival of the Aryan nomads from Egypt and the the Middle East The Vedic civilization that ruled Northern India from about 1750 BC to 500 BC relied heavily upon the cow and the dairy products that it provided It is these Vedas that wrote the first scriptures of the Hindu religion wherein the cow was considered a sacred Probably from the Egyptian god Hathor Greeks and Romans ~1000 B.C. cheese became an important part of the diet Developed dry aged cheeses for long term storage Many of the traditional Italian and Greek cheeses were developed in this time Biblical references referring to Palestine as the "Land of Milk and Honey" Reliance on dairy products grew probably because they were a hedge during bad crop years. High in calories. Also Calcium and Vitamin D help prevent rickets. Especially in Northern climates

Milk produced under the rules of the PMO is called?

Grade A

Which of the following is not true about coliform mastitis?

Gram positive bacteria

Cumsumption of which dairy product has increased the most in recent years?

Greek yogurt

Vacuum Pump

Heart of the system Generates the vacuum that: Removes the milk Massages the teat Moves the milk Sized for the number of units Rated on Hp and CFM How much air can they pull from system? Degree of vacuum measured in inches of mercury Milking requires 10.5-12.5" Hg at the teat end

Pasterization

Heating to kill bacteria in wine Developed in china Louis Pasteur found a more delicate way that preserved the taste Quickly adopted to prevent diseases transmitted by milk TB, Brucellosis, Diptheria, Scarlet Fever etc. Time and temperature dependent Batch, HTST, UHT High Temp - Short Time - Flash Ultra High Temp - Room temperature storage

High Fat to Protein Ratio

Herd of Holsteins at > 3.8 % F Good Thing?? Dairy producer paid for increased fat High butterfat with average of lower milk production Indicator of unfulfilled milk production When F:P ratio > 1.4 Indication that cows are pulling fat off their bodies Predisposes cow to ketosis Ketones produced during fatty acid oxidation

The extent to which genetics influences a trait is called?

Heritability

Heritability

Heritability extent to which genetics influences a trait Determines the extent to which offspring resemble their parents Proportion of the phenotypic differences we see that are due to genetics. Range from 0 to 100% Helps estimate animal's genotype Even lowly heritable traits, such as fertility, can have a genetic component Estimate of the genetic progress that may be achieved with selection. Measure of how much of a trait will be passed on to next generation Faster genetic progress can be made for traits with high heritability

Electronic Mount Detectors

High initial capital investment Computer, antenna, detectors, software False positives: increased activity not always associated with estrus Excellent records: for moving units from cow to cow On-going investment in patches to house devices Requires mounting by cow

Electronic Pedometers

High initial capital investment Computer, antenna, pedometers, software False positives: increased activity not always associated with estrus Work poorly in tiestall barns Portable readers Battery life may be issue Rumination and other information improve efficiency and accuracy Aid in detecting sick cows

Ovsynch is not recommended for heifers because?

Higher conception rates can be achieved in heifers through other synchronization protocols

What breed of dairy cattle originated in Holland and Germany?

Holstein

Holsteins

Holstein Friesians Most populous breed in US Originated in Holland and Germany First imported in 1852 Holstein Association USA (1885) Headquarters - Brattleboro, VT Breed Magazine - Holstein World High milk production Low components - fat and protein Tailored for pricing system Largest in body size Birth weight - 90 lbs Maturity - 1500 lb cows, 2500 lb bulls Black and white or red and white Red and Whites have own breed association Moderate temperament Moderate grazers World Record Holder

Which breed of dairy cattle is best suited to today's milk pricing system?

Holsteins

Stand to be mounted

Holsteins avg 7.5 times per estrus Jerseys avg 10

Heat duration

Holsteins- avg 7 hours Jerseys avg 8.3 hours

Casein can be separated from milk through all the following ways except?

Homogenization

The first step in controlling a mastitis outbreak is?

Identify the causative organism

Use of AI

Important to use on whole herd Take advantage of the genetics Makes no difference whether you use daughter or genomics proven sires Other advantages Safety, disease transmission, accuracy of records, variety of sires, etc. Especially in heifers Sexed semen if you need replacements

Animal Model

In an "animal model", an animal's own phenotypic data is combined with data from all of its maternal and paternal relatives (more weight is given to data from closer relatives)

Which of the following is true about heat mount detectors?

Increase HD efficiency and reduce HD accuracy

How do you milk cows faster?

Increase the vacuum Up to maximum of 15" Hg Increase the milk to rest ratio Up to 70:30 Increase the pulsation rate Until rest phase = 200 milliseconds

Which of the following is not a reason for an increasing number of genetic defects being found in dairy cattle?

Increased emphasis on crossbreeding

Mastitis affects milk composition

Increasing somatic cell count Polymorphonuclear neutrophils Decreasing lactose, casein, and fat production, Increasing blood components such as Na, K, Cl, bicarbonate, IgG and serum albumin. Electrical potential disrupted Bacteria, blood cells and enzymes Proteolysis Lipolysis and globule breakdown Off flavors Changes affect shelf life, cheese/product yield, etc

Which of the following is not a continuing trend in the US dairy industry?

Individual herd size is decreasing

Heat Mount Detectors and Tail Paint

Inexpensive 24-hour observation Easy to interpret Infrequent need to replace if applied properly False positives or activations do occur Detector loss if improperly applied Doesn't tell when mounting occurred Requires mounting by cow

Escherichia coli

Inhabitant of GI tract - Manure Clinical signs include: Subclinical to acute infections Yellow to watery secretion High fever to subnormal temperature Quarter can be hard and swollen Wet milking Septic infusion into udder Antibiotics of little help Supportive therapy Fluids, steroids, antihistamines, antiprostaglandins

Which of the following veins is not part of the udders venous circle?

Internal Pudic Vein

Which of the following statements is not true about udder edema?

It can be prevented by feeding high levels of salt prepartum

Which of the following is not true about selection accuracy?

It goes down when more data on relatives is added

Which of the following statements is not true about clinical mastitis?

It is the most common form of the disease

Which of the following is not true about the genetic base of dairy cattle?

It is the same for all breeds of dairy cattle.

Which of the following is not true about Mycoplasma mastitis?

It is treatable with antibiotics

Which of the following is true about pasteurization?

It makes milk safer to drink

Receiver jar and milk pump

Jar Glass or steel Lowest point and end of all milk lines Milk drains in slowly and collects Milk Pump Located at base of receiver jar Pumps milk through filter sock and up into tank

Which breed is know for the high components in the milk it produces?

Jerseys

Which breed of dairy cattle has the longest productive life?

Jerseys

Lab Pasteurized Count

LPC or Thermoduric Count Milk is pasteurized before plate count Identifies organisms that survive pasteurization Organisms that spoil milk after pasteurization Mastitis organisms usually don't survive NY Study 60% of farms <200 cfu 40% of farms <80 cfu Evaluation Excellent milk <10 cfu Should be below 200 cfu

Lymphatic system

Lactating cow produces about 1300ml /hour Lacteals Originate in the peripheral tissues of the teat ends Move fluids to the lymph nodes Ducts 2-4 main ducts drain the rear udder 1-3 main dusts drain the fore udder Supramammary Lymph Nodes Located in the rear udder

Water

Lactating cows require lots 1 lb. per lb. of milk produced Much more in hot weather Carrier for all the other components Regulated by the lactose production Lactose pumped into the lumen causes osmotic pressure which draws water in

What milk component creates an osmotic gradient which causes water to enter the alveolar lumen?

Lactose

Genetic Defects

Level increased due to AI BLAD - Bovine Lymphocyte Adhesion Deficiency DUMPS - Deficiency of Uridine Monophosphate Synthetase CVM -Congenital Vertebral Malformations Weavers - Brown Swiss Limber Leg - Jerseys Mulefoot - Syndactylism RVC - Recto- Vaginal Constriction - Jerseys

Which of the following is not a part of the alveoli?

Lobule

Which of the following is not an involuntary reason for culling?

Low milk production

24 Day Chart

Low tech approach List of all open cycling cows in herd Check them off the list over the next 24 days Bossy Charlie Cotton #27 #106 (3 of 5 equals 60% detection rate)

Lactose

Major carbohydrate in milk Disaccharide Glucose and galactose molecule Galactose is manufactured from glucose Only found one place in nature The mammary gland Lactose non-permeable Draws water into the alveoli and vesicles Determines the quantity of milk produced

Sources of Strep Ag

Major source is an infected cow. Once eliminated only source is newly purchased cows Injected into udder during milking Squawking Contaminated floors and stalls Heifer calves suckling penmates

Ice Cream

Make or buy an ice cream mix Cream, sugar, flavorings Add additional flavors Large chunks added near end Mix is simultaneously frozen and whipped Outer wall freezes and the dasher (scraper) removes frozen mix and adds air Overrun - The amount of air Package and Freeze

In general, which of the following has the least effect on SPC?

Mastitis

Days in Milk at First Breeding

Measure of early heat detection Evaluated in relationship to Voluntary Waiting Period (VWP) Ideal is 11 days past the end of the VWP DIM FS <VWP + 22 = Good HD DIM FS >VWP +22 = Poor HD

Electrical Conductivity/Resistance

Measures salts in the vaginal mucus Uses a vaginal probe Labor intensive Accurate records of daily readings Accuracy errors Risk of disease transmission is high

Coliform Count

Media only grows Coliform bacteria Coliforms = Manure How do they get in the milk? Cows Can also grow on milk handling surfaces Evaluation Should be less than 10 cfu/ml Count of 100-1000 - Cow cleanliness and prep problem >1000 growth on milk surfaces NY Study 30% <10 cfu 20% >100 cfu Big concern to raw milk dealer

Which of the following structures provides the main support for the udder?

Median Suspensory Ligament

Shell

Metal or plastic tube that houses inflation Creates a space between shell and inflation called the pulsation chamber Short air tube connects to it Responsible for changes in chamber pressure Alternating vacuum and air in this chamber cause inflation to open (milk) and collapse (rest)

Eastern Advantages

Milk Deficit Area Proximity to Large Markets Reduced distances Diversity of markets Fluid Utilization Water Availability Availability of Pasture Land Prices in Rural Areas Strong community support for agriculture

Preliminary Incubation Count - PI

Milk is incubated for 18 hours at 70 F Simulates poor refrigeration Psychrotrophic bacteria Off-flavors and reduced shelf life Measure of raw milk keeping quality Sanitation practices Not associated with mastitis Evaluation Good <10,000, Up to 50,000 is OK NY Study 30% <14,000 cfu 10% <8,000 cfu

PMO Includes

Milk quality sampling and testing Antibiotics residues Adulteration Penalties Stable, parlor and milk house design and construction Cleanliness, personnel, feed storage, water supply Milking equipment and utensils Mastitis and udders cleanliness Drug usage and storage Farm, truck and plant inspections Licensing and permits

Milk Sampling

Milk samples are collected from every farm tank every pick up Official sample used for quality testing and payment Butterfat, protein, SCC, bacteria Person collecting must be certified Tank must be properly agitated before collection Properly labeled and cooled Maintain sample chain of custody This sample is the only "official" sample Producer collected samples don't count

Which of the following is not an indication that a cow has been overmilked?

Milk visible in claw at removal

Control of Contagious Mastitis

Milking procedures Individual cloth/paper towels to wash/dry teats Dip teats with an approved product Predipping especially important Clean hands, latex gloves Milking order or separate claw for infected cows Insure milking system is functioning properly Culture new cows and heifers Minimize teat end lesions Treat all quarters with dry cow antibiotics at end of lactation Cull persistently infected cows Dry treat heifers before calving

Ayrshires

Moderate in size and production Originated in County Ayr Scotland Imported into US in 1822 Ayrshire Breeders Association Headquarters - Columbus, OH Ayrshire Digest Moderate Milk production, butterfat and protein Body size Red (mahogany) and white Markings can be similar to red Holsteins Horns were important Size Birth 70-80 lbs Maturity cows 1300, bulls 2200 lbs. Excellent grazers Known for bad temperament White fat

Control of Environmental Mastitis

More difficult to control than the contagious pathogens Most are resistant to germicides in teat dip and antibiotics in dry cow therapy Key is to ID source and remove (bedding, ponds, mud) Milk only clean dry teats Clean parlor, stalls, alleys etc. Clean dry bedding Barrier dips Predip teats with germicide before milking No water / drop hoses in parlor Keep cows standing after milking - feeding Sterile single-dose infusion products Sterile infusion techniques (alcohol swab) Clip or flame udders

Which of the following is true about mastitis caused by Steptococcus agalactiae?

Most cases are subclinical

Milk ejection reflex

Neuroedocrine Pressure sensitive receptors on the teats feed back to the supraoptic and paraventricular nuclei Stimulation of these neurons causes release of oxytocin Other stimuli can cause letdown Oxytocin causes myoepithelial cells to contract Peak oxytocin 2 mins following stimulation Half life of .55 - 3.6 mins Timing of stimulation important to milk flow rate and machine-on time Machine attachment in 60-90 seconds Adrenalin blocks letdown by: Decreasing mammary blood flow Reducing myoepithelial response reducing oxytocin release

Subclinical

No evidence of abnormality except milk positive on special tests

Subclinical mastitis can not be detected by?

Observing clots and flakes in the milk

Selection Index

One trait that is a function of several traits Can give each included trait a different weight Simplifies selection because your looking at one trait Maximizes genetic progress Can calculate your own Need to consider, mean, range and variation in each trait included

Inflations or liners

Only part that touches the cow Hundreds of different styles, shapes and sizes Bore sizes - narrow, medium Usually made of rubber or silicone Rubber good for 2000 milkings - Silicone 5000+ Replace when recommended Wall thickness and stiffness - Important Shape when collapsed - round, triangular, square Short milk tube, Mouthpiece, Air vents,

Modern Cows

Originated from domesticated aurochs Roamed Europe, Africa and Asia beginning in the Pleistocene period Oldest fossils 2 million years ago in India Moved into Europe 250,000 years ago Gave rise to Zebu cattle in India and Pakistan Gave rise to Taurine cattle in Middle East Bos taurus Size 6-8 feet tall and weighing 1500 to 3300 lbs Horns up to 30" in length Around in human times Cave paintings Described by Julius Caesar in his account of the Gallic War Last remaining aurochs died in 1627

Brown Swiss

Originated in Switzerland Oldest of breeds First imported to US in 1869 Brown Swiss Cattle Breeders Association Headquarters - Beloit, WI Magazine The Brown Swiss Bulletin Large size - similar to Holsteins Moderate production High protein to fat ratio Dual/Tri purpose breed Milk, meat and draft Lack dairyness Near white or silver to dark gray Sound legs Longevity Extremely mild temperament - Slow

Guernseys

Originated on Isle of Guernsey Channel breed Used to be most populous breed First imported in 1840 American Jersey Association Headquarters - Reynoldsburg OH Magazine - Guernsey Breeders Journal Low milk production, high components Similar to Jersey Milk is yellow "Golden Guernsey" Brindle and white, spotted Birth - 65 - 70 lbs. Mature 1100 cows, 1800 bulls Not good at converting carotene in vitamin A Yellow fat Yellow muzzle and around eyes Good grazers Poor conformation

The following injection protocol is an example of what? Day 1 - GnRH Day 7 - Prostaglandin Day 9 - GnRH 16-20 hours later - Inseminate

Ovsynch

Accuracy

Percent of cows actually in heat at breeding Error - Breed cow not in heat Mistakes Costs Semen Days Requires progesterone testing to determine

Efficiency

Percent of heats caught Error - Missed heat Mistakes Cost Days

A visual property of an animal, either masured or abserved is called?

Phenotype

Casein

Phosphoproteins - about 80% of all milk proteins Lack Disulfide bonds and has little secondary and tertiary structure Form a micelle (140nm) - hydrophobic Calcium and phosphates stabilize structure Several forms Alpha - phosphorylated form S1 and S2 variants (39%) Beta - major (28%) Kappa - glycoprotein (10%) Stabilizes the micelle Gamma - fragments of beta (3%) Precipitated by pH below 4.6 - Low solubility - Clots in stomach Ultracentrifugation Ultrafiltration - reduce trucking costs of milk used for cheese. Rennin - cheese Cleaves Kappa casein

Selection

Picking the parents of the next generation Not much selection done on the maternal side Increase frequency of "good" genes in population Influenced by: Genetic Variation Accuracy of Selection Intensity of selection Number of traits selecting for Generation Interval

Which of the following is not a common type of milking parlor?

Pipeline

In the animal model, what do the letters PTA stand for?

Predicted transmitting ability

Maine Dairy Industry

Predominantly small family farms ~100 cows/herd Undeveloped capacity to produce milk Importer of dairy products Especially cheese Large percentage of organic producers 20% - Highest in nation (only 10% of milk) Increasing number of artisan cheese producers High utilization of milk for fluid products Higher than average milk prices (ranked 8th in nation) Maine Milk Commission - State subsidy - Maine MILC Few processors and handlers - Little competition for milk Lack of infrastructure Equipment, structures, consultants, vets, feed companies, ag lenders etc.

Which group of animals in the herd should have the highest PTA for milk production?

Preweaned calves

CIDR's sychronize estrus because they conatin what hormone?

Progesterone

Which of the following is not a way to alter the milking system to speed up milking?

Reduce the vacuum in the pulsation chamber

Controlled breeding programs improve reproductive performance mainly by?

Reducing days to first service

Standard Plate Count

Referred to as the Bacteria Count or SPC Good overall measure of milk quality Difficult to diagnose problem from a single test Run monthly or more frequently Determines the number of colony-forming units in one milliliter of milk Incubated at 90 F for 48 hours High bacteria counts come from: Inside the cow - Mastitis Outside the cow - Udder prep Inside the equipment - Sanitation Growing in the tank - Cooling

Genetic Base

Refers to a group of animals used as a reference point when calculating genetic evaluations PTA, EBV, and PA for all other animals are expressed as a deviation from the base animals The current base (2010) is: The average PTA for sire-identified cows born in the USA in 2010 is set to zero (for each breed and for each trait) The genetic base is updated every 5 years, because genetic selection leads to higher PTA values each year

New England Dairy Industry

Represent only 4% of National production Except for VT, the states are net importers of milk Most of the milk is used for drinking Dairy makes up large percentage of agricultural receipts #1 in VT, NH #2 ME, RI, CT #3 in MA $871 Million Industry Public supportive of dairy farming State milk subsidies Problems with urban sprawl

The most common reason cows are culled from a dairy herd is?

Reproduction

Genomics looks for many tiny changes in the DNA that make each individual different. These tiny changes 1 base changes are called?

SNiP's

What part of the milking system separates the "clean" or milk side from the "dirty" or pump side of the system?

Sanitary Trap

Which of the following is not true about linear scoring?

Scores range from 0 to 50, with 50 always being the best score

Jerseys

Second most populous breed Originated on Isle of Jersey Channel breed Imported in 1850's American Jersey Cattle Club Oldest US dairy breed association Headquarters - Reynoldsburg, OH Magazine - Jersey Journal Growing because of cheese production Highest Butterfat and Protein Dark brown to gray and silver Can have spots Black muzzle and eyes Yellow fat - Poor carotene conversion to Vitamin A Refined dairyness Smallest Birth - 65 lbs Mature - 1100 lb. cows, 1600 lb. bulls Good grazers Efficient relative to size Aggressive for size Prone to milk fever Calves have poor survivability

The most important step in breeding a dairy herd is?

Selecting the sires used to breed the herd

Genomics has the greatest effect on which of the following factors affecting genetic progress?

Selection accuracy

The degree to which a selected population of parents exceeds the average of the population is called?

Selection intensity

Sanitary Trap

Separates vacuum side (dirty) from milk side (clean) Traps water and milk and keeps it from going through vacuum pump Usually a ball valve in bottom that shuts off vacuum if water/milk gets too high

Percent Detected Heats

Services/Conception-1) x 21 ----------------- Days open-VWP

Milk Proteins

Several types found in milk Casein - 76% Whey proteins - 18% beta lactoglobulin alpha lactalbumin Lactose synthesis Serum proteins Blood Serum albumin Enzymes, hormones, antibodies, growth factors, lactoferrin, NPN Major proteins are unique to milk Amino acids balanced for growth Manufactured from AA's

Historical Methods of Estimating Genotype

Show winners Dam - Daughter Comparisons Herdmate Comparisons Nationwide comparisons Modified Contemporary Comparisons Base year, cow index Animal model Considers all relatives PTA

In which type of parlor are the cows arranged head to tail on either side of the milker pit?

Side Opening

Milkfat Globules

Size ranges from 0.1 to 15 microns in diameter Covered by a thin membrane from secretory cells (Protein and Phospholipids) Helps prevent coalescence and flocculation Protects fat from enzymatic action Properties enable the production of butter, whipped cream and ice cream Homogenization Decreases diameter making them more stable in suspension

Udder suspensory system

Skin Superficial fascia Coarse aereolar tissue Fore udder to abdominal wall Lateral suspensory ligaments Superficial Deep Arise from the subpelvic ligament and prepudic tendon Median suspensory ligament Main suspension Elastic

Fertility Haplotypes

Small section of the DNA that is inherited as a unit A group of SNPs that are inherited as a group JH1 is one SNP difference A mutation that causes a single gene to lose function Gene important in the formation of mRNA JH1 (23.4%) Observer Chocolate Soldier Top Brass, Sooner, Beretta, Hallmark, Paramount, Jace, Louie

Mastitis causes an increase in which of the following milk components?

Sodium

Milk Composition

Solution - dissolve to the molecular level Lactose Minerals Suspension - Colloid, particles so small they will not settle out Proteins - Casein Emulsion - compounds that don't mix with water Butterfat

Other things found in milk

Somatic cells Bacteria Viruses Yeasts Molds Sediment Hormones Antibiotics Drugs Disinfectants Pesticides Aromatic Compounds Environmental Toxins Heavy Metals Radioactive Isotopes Excess Water

What Milk Standards Does PMO Set?

Somatic cells No greater than 750,000/ml Bacteria limits No greater than 100,000/ml Drugs No positive results on residue tests Temperature Cooled to 50 F or less within 4 hr of the start of first milking Cooled to 45 F or less within 2 hours after milking Blend temp does not exceed 50 F after that

Milking Shorthorns

Split from beef Shorthorns One of oldest recognized breeds Originated in Great Britain First imported to US in 1783 American Milking Shorthorn Society Headquarters in Beloit, WI The Milking Shorthorn Journal Tri purpose breed Low milk production, low components Moderate in size Reddish brown and white Spotted or speckle, roan Lack dairyness Good grazers

The only definitive sign of heat in cattle is?

Standing to be mounted

An injection of GnRH has what effect on the ovaries of the cow?

Starts a new follicular wave

Which of the following is not a cause of off flavors in milk?

Storage

Streptococcus agalactiae

Strep Ag Gram positive Inhabits ducts and cisterns Does not survive in environment Inflammation blocks ducts Leads to decreased milk production, increased somatic cell count and involution Few enzymes/toxins produced Common "Old Form" Still common in poorly managed herds Well managed herds eradicated it Causes 20-40 subclinicals for each clinical Susceptible to penicillin and other antibiotics Can eradicate from herd with "Test & Treat" program Dry cow treatment highly effective Proper sanitation and milking procedures prevent cross infection

Streptococcus species

Strep non-ag, Environmental streps Strep uberis, dysgalactiae, and bovis Inhabitants of GI tract Infection rates highest before calving Behave like traditional mastitis organisms with chronic infections and high SCC's Clinical signs Similar milk infections with clots and flakes Moderate swelling High SCC Only mastitis organisms that elevate bulk tank plate count Prevention Milking sanitation, milk clean dry teats, predipping, clean up environment of dry cows, switch to sand bedding.

Mulefoot

Syndactyly Autosomal recessive Varying degrees of expression (severity) Substitution of 2 consecutive nucleotides on Chromosome 15 Causing 2 amino acid sequence change Carriers: Raven Burke Ideal Wayne Springs Fond Apollo

3 types of milking routines

Territory Rotating or sequential Combination

Genetic Variation

The amount of variation in the genotypes of the individuals in the population More variation - More genetic progress possible Cannot practice genetic selection unless genetic differences exist between animals Breeding for white in the Angus breed

A dairy animal that has a PTA for milk of +2000 means?

The animal's offspring will produce 2000 lbs more milk per lactation than the average cow in the genetic base year.

Which of the following factors does not affect the phenotype of an animal?

The number of relatives in the pedigree

Dairy Trends

The trends in production and herd size have been ongoing for many years Milk consumption continues to go down except for cheese and yogurt Dairy is important to states in the north and east Dairying continues to expand in the west for a number of reasons, however the East can still be competitive

Milkfat Synthesis

Two Sources Blood (VLDL) Longchained FA FA Synthesis Short Chained - Acetate and Betahydroxy Butyrate Occurs in cytoplasm Small lipid droplets coalesce in cytoplasm

Selection Intensity in AI

Two-Stage Selection Selection of elite sires and dams to be parents of young bulls Dams (Top 1% of population) Sires (From AI) Selection among young bulls based on genomic and/or progeny test results (Top 10% are marketed) Selection Intensity - 0.0003%

Selection vs. Mating

Two-step process - Select first then Mate! Step 1 Use an index to select the service sires that will be used in your herd Step 2 Use a mating program to match each cow to one of these service sires Most of the genetic gain will come from step 1!

Clinical

Udder shows signs of inflammation (Redness, swollen, tender, hard, etc.) Milk is abnormal Flecks, gargot (clots), off color, bloody Goal <2% per month

What part of the milking system crerates the vacuum that extracts the milk from the cow?

Vacuun Pump

Genomic Selection Disadvantages

Variability available for future genetic gain would be reduced. The rate of genetic gain would diminish over time. Incorrect associations between phenotypes and the SNPs could lead to unexpected results, some of which would be unfavorable.

Phenotype

Visible properties of an organism Measured or observed Three components = G + E permanent+ E temporary Genetic effects The variability due to genetics is heritability Permanent environmental effects Care a calf receives while growing up Illness that causes permanent effect Temporary environmental effects Age at calving Illness with no permanent effect

Causes of Accuracy Errors

Visual observation is subjective Many different signs of heat Varying reliability Standing to be mounted is the only definitive sign of heat Not every cows shows the definitive sign Boss cow Foot or footing problems

Match the milk component with its average percentage in milk

Water E. 87.5 % Lactose A. 4.9 % Butterfat D. 3.7 % Protein B. 3.2 % Minerals C. 0.7%

Composition of Cow's Milk

Water 87.5% Lactose 4.9% Protein 3.2% Casein 2.9% Lactalbumin 0.52% Lactoglobulin0.20% Fat 3.7% Minerals 0.72% Calcium 0.12% Phosphorus 0.11% Chlorine 0.11%

Which of the following is not a reason dairy production has moved to the Western US?

Water availability

Which of the following is not a genetic defect of Holsteins?

Weavers Disease

Antibiotic Testing

When milk reaches the plant or transfer station - sample is taken an screened for antibiotics Truck is not allowed to unload at plant until test is negative If truck sample is "hot" for antibiotics All official farm tank samples are tested to locate the source Maximum legal allowable limits set for each drug Penicillin - 10 ppb Oxytetracycline - 30 ppb Sensitivity levels of each test is usually below this limit Charm II - penicillin >3.4 ppb( < 1 drop in Olympic sized pool) Snap Beta-lactam - >3 ppb A positive test is a positive test Even if level is found to be below 10 ppb

Staphylococcus aureus

#1 cause of mastitis in US Many forms Acute, chronic, subclinical (chronic, subclinical predominates) Facultative intracellular pathogen Produces many enzymes/toxins (catalase, coagulase) Invasive-hyaluronidase Resists phagocytosis & immune system Forms abscesses; may result in fibrosis Damage to secretory tissue reduces milk production and increased somatic cell count Transferred mainly via milking machine and milker Proper sanitation and milking procedures prevent cross infection Hands - Gloves Difficult to eliminate Cull, Milk separately or last Some environmental survival Skin, bedding Antibiotic resistance resulting from genetic mutations Difficult to treat High doses of antibiotics during dry period Early detection critical to successful treatment May be isolated from mammary gland of heifers Found in combination with other bugs

265-300º UHT

1-3 seconds

Place the following steps in order (first to last) to properly milk a cow?

1. Put on gloves 2. Let the cow know you are approaching 3. Predip teats 4. Strip milk from each quarter 5. Wipe off predip 6. Attach and adjust unit on cow 7. Cut vacuum and remove unit when milk flow ceases 8. Postdip

An increase of one unit in SCS results in decrease in daily milk production of about?

1.5 lb

Estrus synchronization can be achieved with two injections of prostaglandins given how many days apart?

11

100 lbs of milk

11.6 gallons

Batch pasteurization involves heating milk to what temperature for how long?

145 degrees for 30 minutes

Increased milking frequency on milk production

1X-2X 13.6 lb 2X-3X 7.7 lb 2X-4X 10.8 lb

What is the minimum time that predip should remain on the teats for proper disinfection?

20 Seconds

A cow is considered to have mastitis if her individual SCC is higher than?

200,000

How many pounds of milk does it take to make one pound of butter?

22

Pedometers

24-hour detection Some can pinpoint when activity started Decreased labor if used properly Component of automated ID systems in some units Easy to use computer software High initial capital investment Accuracy - false positives increased activity not always associated with estrus Need excellent records

A cow with a CL that responds to prostaglandins will come in heat approximately how many days after injection?

3

145º Batch

30 minutes

With good parlor efficiency in a herringbone parlor, how many turns should be achieved per hour?

4

Tha average heat detection efficiency of dairy herds in the US is about?

50%

Peak milk usually occurs at?

6 - 10 Weeks

Research shows that milking cows in early lactation, 4X to 6X per day, will result in an increase in daily milk production for the entire lactation of?

6 lb

For best milk out, the milking unit should be be put on the cow how long after udder stimulation?

60 Seconds

What percent of cows will respond to a single injection of prostaglandins by coming into heat?

60%

Cows are in estrus an average of how long?

7-8 hours

On average, increasing milking frequency of a cow from 2X to 3X daily will result in how much additional milk per day?

7.7 lb

Many cows leave the herd soon after calving due to infections and metabolic disorders. What is a good goal for the percent of a herd culled in the first 30 days following calving?

<6%

Intensity of Selection

A measure of the degree by which performance of the selected group of parents exceeds the average of the population Intensity is a function of: Population size Percentage of animals selected Few animals selected = High intensity Large population = High intensity The greater the intensity, the greater the genetic progress Different for cows and bulls All cows need to carry calf to produce milk A very small number of bulls needed to breed all cows

What is a haplotype?

A small section of DNA inherited as a unit.

Genetic Change/Year

Accuracy x Intensity x Genetic Variation ------------------------ Generation Interval

A Holstein cow whose milk fat and protein ratio is inverted may have?

Acidosis

Which of the folowing is not a permanent environmental effect on an animal's phenotype?

Age at calving

In dairy cattle breeding, the selection intensity on the maternal side is low because?

All the cow's have to have a calf to produce milk.

Interior if udder

Alveoli Milk producing units Secretory cells, myoepithelial cells and capillaries, ductule Lobules 150-200 alveoli, one common duct Lobes Group of lobules Duct system Drains secretory tissue No secretory function Gland cistern 100-400 ml. milk storage Duct systems drains into Used to detect end of milking

Which of the following organizations does not collect genetic information on dairy cattle?

American Dairy Science Association

The current method of predicting a dairy animal's breeding value is?

Animal model

Environment

Animal's opportunity to express a trait Conditions under which the animal is raised Some conditions have very short term effects, Others very long or permanent. Short term What she was fed today Long term Pneumonia as a calf Phenotype is clouded by environmental factors

Other Compounds Normally Found in Milk

Anything found in the blood is found in milk Acids Citrate, Formate, Acetate, Lactate, Oxalate Enzymes Peroxidase, Catalase, Lipase, Phosphatase Gases Oxygen, Nitrogen, Carbon dioxide Salts

Which of the following increases selection intensity for a trait?

Artificial insemination

Klebsiella

Associated with soil contamination Grows well in wood products Becoming more common in herds that use other bedding types Builds up in the environment over time Switch bedding Maintain high pH in bedding Clinical signs very similar to E. coli

Modern dairy cows originated from ancient large wild roaming cattle called what?

Aurochs

CVM

Autosomal Missense Recessive One amino acid substitution Causes abnormal nucleotide-sugar transport into the Golgi apparatus, leading to malformations of the vertebral column Spontaneously abort or die shortly after birth Carriers: Penn State Ivanhoe Star Carlin-M Ivanhoe Bell (Son) Popular in 1980's In 2011 Bell represented 9.0 % of all the genes in AI bulls in the US

Generation Interval

Average age of parents Quicker you turn over generations the more genetic progress you'll make Heifers have the most modern genetics in herd Produce 35-40% of calves Dairy cattle - 4-5 years AI - Increases GI - 7-8 years ET - Increase GI by 1 year MOET - Select heifers - GI = 2

Which breed of dairy cattle originated in Scotland?

Ayrshires

Mastitis is almost always caused by a?

Bacteria

The Standard Plate Count measures the number of what in milk?

Bacteria

Contagious Mastitis

Bacteria primarily live on/in the udder and teat lesions Poor survival of bacteria in the environment Spread from cow to cow Most often during milking by milk-contaminated fomites at milking, sponge, milker's hands, milking machine Contagious mastitis causing organisms Staphylococcus aureus Streptococcus agalactia Mycoplasma bovis Sometimes Streptococcus uberis Usually cause chronic, subclinical mastitis

Milk grades (A and B)

Based on production quality standards PMO defines the standards for Grade "A" Everything else is Grade "B" Nearly all milk produced in the US is Grade A Exceptions are unlicensed and religious restricted producers

Milk Classes (1-4)

Based on what the milk is used for Class 1 - Fluid milk (drinking) Class 2 - Soft cheeses and yogurt Class 3 - Hard cheeses Class 4- Butter and powdered milk

Genomic Evaluations

Based the actual DNA As opposed to phenotypic traits Identify DNA markers for an single trait at a single locus Red in Holsteins, Polled, Genetic lethals DNA techniques now make it possible to scan large sections of the DNA for little substitutions Correlate what is seen phenotypically in the animal with the DNA sequences Not just on simple traits but on milk production and other quantitative traits. Revolutionize animal breeding!

Mycoplasma

Between a bacteria and a virus - M. bovis primary species No cell wall so antibiotics are ineffective Characterized by sandy granules and tan colored milk Spread through contaminated antibiotics, syringes milking units, common cloths, etc. Teat dipping is a good preventative Control by biosecurity Isolation and culling Usually in well-managed herds Also causes respiratory disease and ear infections in calves, joint infections, and occasional abortions NY and WI studies showed 8-10% of herds have infected cow Maine BT Study 2002 - 3% of herds Shedding of organism is sporadic

Whcih fo the following sample types cannot be used to genomically test young calves due to mixing of cells in twins?

Blood

Vascular system

Blood:Milk Ratio; 500:1 2 Arteries External pudic Perineal 3 Veins External pudic Perineal Subcutaneous abdominals milk wells Venous circle

Weavers

Bovine Progressive Degenerative Myeloencephalopathy Autosomal recessive disease affecting Brown Swiss Chromosome 4 Weakness that develops into total loss of limb function Starts at 6-18 months of age

Cheese

Breaking down the casein micelle causes the milk to clot Rennet, acid, bacteria Pasteurize milk Raw milk cheeses must be aged Allow milk to clot Drain off whey, what remains the curd Rinse curd, salt, press and age depending on the type of cheese Maine has the second largest number of licensed artisan cheesemakers in the US