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Dairy glossary

The abbreviations and terms that show up on milk reports, herd records and vet visits, in plain English.

BCS (body condition score): A 1 to 5 score of how thin or fat a cow is. Tracked through lactation to see whether cows are gaining or losing too much condition.
Bulk tank: The refrigerated tank where milk is cooled and held until the milk truck picks it up.
BVD (bovine viral diarrhea): A viral disease of cattle managed through testing, vaccination and biosecurity. Ask your vet about a plan for your herd.
Butterfat: The fat in milk, one of the milk components that affects the price paid in many pricing systems.
Class I, II, III and IV milk: Federal order categories for milk by use. Class I is fluid milk, Class II is soft products such as ice cream and yogurt, Class III is cheese and whey, and Class IV is butter and dried milk products.
Clinical mastitis: Mastitis you can see, with abnormal milk, a swollen udder or a sick cow.
Colostrum: The first milk after calving, rich in antibodies. Calves need it quickly after birth.
Cwt (hundredweight): A unit equal to 100 pounds. Milk prices are commonly quoted per cwt.
DHI / DHIA: Dairy Herd Improvement, the testing program that measures individual cow milk yield and components and reports them to the farm.
Digital dermatitis: A painful, contagious foot condition of cattle, often at the heel. Managed through hoof care, footbaths and clean, dry conditions as your vet advises.
DIM (days in milk): The number of days since a cow calved.
Displaced abomasum: A condition where the fourth stomach shifts out of position, most often around calving. Needs veterinary care.
DMI (dry matter intake): How much feed, measured without its water content, a cow eats in a day.
Dry period: The rest period between lactations before the cow calves again.
Estrus (heat): The few hours when a cow is receptive to breeding. Detecting it on time drives breeding success.
FARM program: The National Dairy FARM Program, an industry animal care and stewardship program.
FMMO (federal milk marketing order): Federal rules that set minimum prices handlers pay for milk in regulated regions.
Forage: Fibrous feed such as grass, hay, haylage and corn silage.
Fresh cow: A cow that has recently calved, in the early days of lactation.
Freestall: A barn layout with individual resting stalls and open alleys.
Haylage: Forage cut and stored wet and fermented, with less drying than hay.
Heifer: A young female that has not yet had a calf.
Income over feed cost (IOFC): Milk income minus feed cost, a quick check of margin. See the calculator on this site.
Johne’s disease: A chronic intestinal disease of cattle that spreads slowly in herds. Managed through testing, culling and calf management with your vet.
Ketosis: A metabolic disorder when a fresh cow cannot take in enough energy and burns body fat too quickly.
Lameness: Abnormal walking, usually from foot or leg problems, one of the biggest welfare and production issues on dairies.
Mastitis: Inflammation of the mammary gland, most often from infection.
Metritis: Infection and inflammation of the uterus after calving.
Milk fever (hypocalcemia): Low blood calcium around calving that can cause weakness and a downed cow. Needs prompt veterinary attention.
MUN (milk urea nitrogen): A lab value nutritionists use as one clue to how protein is being fed and used.
NDF (neutral detergent fiber): A feed test measuring the total fiber in forage and rations.
Parlor: The milking area where cows are milked, with stalls arranged in layouts such as parallel, herringbone or rotary.
Pregnancy rate: The percentage of eligible cows that become pregnant in each 21-day period. A key measure of reproductive performance.
Retained placenta: When the afterbirth is not expelled within the normal time after calving.
SARA (subacute ruminal acidosis): Periods of low rumen pH that can reduce intake and milk fat and harm cow health.
SCC (somatic cell count): The count of cells, mostly white blood cells, in a milliliter of milk. A major indicator of udder health and milk quality.
Silage: Chopped forage, often corn or grass, stored and fermented for feed.
Springer: A heifer or cow close to calving.
Subclinical mastitis: Mastitis with no visible changes in the milk or udder. It shows up in cell counts and tests.
TMR (total mixed ration): A mix of forages, grains and supplements blended so each bite is the same.
Transition period: The weeks just before and after calving, when many health problems occur.
Voluntary waiting period: The time after calving that a farm chooses to wait before breeding a cow.
Withdrawal time: The period after treatment during which milk or meat cannot be sold. Follow the label or your vet exactly.