P

Parakeratosis Any abnormality of the stratum corneum (horny layer of epidermis) of skin, especially a condition caused by edema between the cells, which prevents the formation of keratin.
Parallel milking parlor A raised milking area or platform where the cow stands perpendicular to the operator and milking units are attached between the rear legs. Also called side-by-side.
Parenteral Administration by injection, not through the digestive tract (e.g., subcutaneous, intramuscular, intrasternal, intravenous).
Parity price A level of farm prices intended to provide the same approximate purchasing power for farmers as enjoyed during a preceding base period.
Parrot mouth A malformed mouth of an animal in which the upper jaw abnormally protrudes beyond the lower. 
Parturient paresis. A condition (observed especially in highproducing dairy cows) characterized by a low blood calcium concentration which results in partial to complete paralysis soon after parturition called milk fever.
Parturition The act or process of giving birth to young. 
Pasteurization The process of heating milk to at least 62.8øC. (145øF.) and holding it at that temperature for not less than 30 minutes (holding method); to 71.7øC. (161øF.) for 15 seconds (HTST); to 88.3øC. (191øF.) for 1 second, to 95.5øC. (203.9øF.) for 0.05 second, or to 100øC. (212øF.) for 0.01 second (ultrapasteurization).
Pasteurized Milk Ordinance (PMO) Regulations approved by FDA governing the design and maintenance of dairy farms and processing plants to make sanitation and milk quality uniform across state lines.
Pasture Plants, as grass, grown for feeding or grazing animals. Also to feed cattle and other livestock on pasture. 
Pathogen Any microorganism that produces disease (bacteria, viruses, yeasts, molds, and parasites). 
Paunch (rumen) The large, first stomach compartment of a ruminant. 
Pediculicide An agent that destroys lice. 
Pedigree A record of an animal's ancestors, usually only those of the five closest generations. A complete pedigree may include milk production, type classification, and other information pertaining to dairy cattle.
Pendulous udders Loosely attached mammary glands are collectively referred to as pendulous udders. 
Percentile (%ILE) For bulls, percentile (%ILE) is a ranking based on the Active AI bull population; for cows, %ILE is a ranking based on cows with recent lactations. With the Animal Model, PTA$ Protein is used to determine percentiles.
Permanent identification Identification that stays with the animal for its lifetime and cannot be lost. Examples are tatoo, color markings (sketch or photo) and hot or freeze brand. (Also see unique identification.)
Persistency The quality of being persistent, as in the ability of lactating animals to maintain milk production over a period of time.
pH A logarithmic measure of the acidity or alkalinity of a solution using the hydrogen ion concentration. The pH scale ranges from 0 to 14 with numbers above 7 being alkaline and numbers below 7, acidic. A one number change means the solution is ten times weaker or stronger than the previous measure.
Phenotype The expression of genes that can be measured by our senses--what we physically see of some trait in an animal. 
Phosphate An ion of phosphorus and oxygen (H2PO4- or HPO4-2). May exist as an ion in solution or as an ester or salt of phosphoric acid.
Pica A craving for unnatural articles of food such as is observed in phosphorus-deficient animals; a depraved appetite.
Pink eye (conjunctivitis) An inflammatory disease of the eye of cattle of all ages. The eye may become pearl colored and opaque leading to blindness.
Pipeline A stainless steel or glass pipe used for transporting milk by gravity to storage. May be above the milking units (high line) or below the level of the units (low line).
Placenta The tissue attachment between the fetus and the mother. 
Plain A term suggesting general inferiority; coarse; lacking the desired quality or breed character. 
Plasma The liquid portion of blood or lymph in which corpuscles or blood cells float. 
PMO See Pasteurized Milk Ordinance. 
Polled Describing a naturally hornless animal. 
Polygastric Possessing more than one stomach compartment, as does the cow and other ruminants. 
Pool, cooperative Each producer who belongs to a cooperative receives a common blend price calculated on the basis of use of all milk sold through the cooperative.
Pool, individual handler A pool in which each producer selling raw milk to a single handler (dealer) receives the same blend price for milk regardless of the use made of any individual producer's milk.
Pool, marketwide A pool in which each producer supplying a market receives the same uniform price for milk calculated on the basis of use of all milk received by handlers in the market.
Post-legged A condition in which the hind legs are too straight, so that the springy quality of the hock and pastern is lost.
Postpartum Occurring after birth of the offspring. 
Potash An oxide of potassium (K2O) used as a plant nutrient or fertilizer. 
PPA See predicted producing ability. 
Ppb Parts per billion. It equals micrograms per kilogram or microliters per liter. 
Ppm Parts per million. It equals milligrams per kilogram or milliliters per liter. 
Predicted Producing Ability (PPA) An estimation of the amount of milk and/or components that a cow will yield above or below herdmates based on the cow's pedigree information and performance, if available.
Predicted Transmitting Ability (PTA) An estimation of an animal's potential to transmit yield productivity to its offspring based on pedigree information and the animal's performance, if available.
Preliminary milking The first milking of a three-milking verification test for herds milked twice daily. 
Premature calving Termination of pregnancy during the last trimester. 
Prepartum Occurring before birth of the offspring. 
Prepotent Designating an animal that transmits its own character to its progeny to a marked or highly uniform degree.
Primary waste treatment Usually, the initial treatment of waste water to reduce pollution potential or health hazard. With animal manure an example would be liquid-solid separation.
Produce A female's offspring. The produce of dam commonly refers to two offspring of one dam. 
Producer settlement fund (equalization fund) A fund maintained by the market administrator into which some processors pay money, because they use above average proportions of milk as
Class I, and from which other processors receive money, because they use below average proportions of milk as Class I. This fund is used in conjunction with a marketwide pool.
Production and type index (PTI) Combines genetic merit measurements for production and type in a ratio thus ranking sires on their ability to transmit a balance of these traits.
Production report The computer report of production and management data which is returned to the dairy producer 5 to 7 days following the test day and after component sampling is completed at the laboratory. The records are processed at one of the DRPC's.
Progeny testing Evaluating the genotype of an individual by a study of its offspring. An evaluation of the transmitting ability of an individual based on the performance of offspring.
Projected 305-day lactation A calculation for predicting a cow's total yield in 305 days based on the information from a lactation in progress.
Prolapsed uterus A condition in which the uterus is partially or completely turned inside out, outside the animal's body, usually following parturition.
Proprietary handler A milk processing company owned privately or publically by investors other than milk producers. The business differs from a cooperative. 
Protein See milk protein. 
Protein equivalent A term indicating the total nitrogen content of a substance in comparison with the nitrogen content of protein (usually plant). For example, the nonprotein nitrogen (NPN) compound, urea, contains approximately 45 percent nitrogen and has a protein equivalent of 281 percent (6.25 x 45 percent).
Protein supplements Feed products that contain 20 percent or more of protein. 
Proven sire A bull whose genetic transmitting ability has been measured by comparing the milk production performance of his daughters with that of the daughter's dam and/or herdmates under similar conditions. Plus-proven sires are those whose daughters exceeded their dams and/or herdmates in milk production.
Proximate analysis Tests for nitrogen (crude protein), crude fiber, ether extract (lipids), and ash which, with nitrogen-free extract, represent the gross composition of feed.
Psychrophilic Cold-loving. It refers to microorganisms that grow best at refrigerated temperatures, that is, 4 to 15øC. 
Psychrotrophic Cold-tolerant. It refers to microorganisms that grow at low temperatures, 4 to 15øC., but may have an optimum temperature above this range. These organisms especially affect the shelf life of refrigerated dairy products such as cottage cheese.
PTA See predicted transmitting ability. 
PTI See production and type index. 
Purebred The offspring of purebred parents of the same breed. Ancestors of purebreds can be traced to foundation stock in the original herdbook. An animal with two registered parents of the same breed. Purebreds are not all registered.
Purebred Dairy Cattle Association (PDCA) An organization made up of members of the six purebred dairy cattle registry associations: Ayrshire, Brown Swiss, Guernsey, Holstein, Jersey and Milking Shorthorn.
Pus A liquid product of inflammation consisting of leukocytes, lymph, bacteria, deadtissue cells, and fluid derived from their decomposition.
Pyometra An accumulation of pus in the uterus.