the fourth stomach of a ruminant equivalent to the only stomach present in animals with single stomachs. The abomasum secretes acids and enzymes to digest feed.

premature expulsion of a non-viable foetus from the uterus after 45 days of pregnancy and before the normal 282-day term.

a condition characterized by an elevated concentration of ketone bodies in body tissues and fluids. It is more common among high-producing animals in a negative energy balance.

fibre measurement extracted with acidic detergent in a technique employed to help appraise the quality of forages. Includes cellulose, lignin, ADIN, and acid-insoluble ash.

fluid milk product obtained during the manufacture of cheese, casein or similar products by separation from the curd after coagulation of milk and/or of products obtained from milk. Coagulation is obtained, principally, by acidification. (Codex Alimentarius)

milk quality test that measures lactic acid.

antibody production as a result of immunity acquired from previous exposure to pathogenic microorganisms (as opposed to passive immunity).

at pleasure. Commonly used to express feed available on free-choice basis.

addition of other substances to milk which reduces the quality of the milk (e.g. water).

requiring oxygen. For example, many microorganisms require oxygen for the oxidation of food materials.

the placenta and allied membranes with which the foetus is connected with the mother. It is expelled from the uterus following parturition.

failure to secrete milk following parturition.

age determined by subtracting the cow's birth date from her most recent calving date.

female offspring of an artificially inseminated dam.

milk quality test. It is used to screen and rapidly assess acidity.

a walking area for cattle within a barn.

a colourless pungent gas, NH3, composed of nitrogen and hydrogen; its compounds are used as fertilizers.

an ion (NH4+) derived from ammonia (NH3).

disease due to a deficiency in iron and (or) the lack of red blood cells.

species of bacteria that live in the absence of oxygen, which is toxic to them.

a structure to treat animal waste by predominantly anaerobic biological action using anaerobic or facultative organisms, in the absence of air, for the purpose of reducing organic matter in wastes.

a unit of measurement of livestock, the equivalent of one mature cow weighing 1 000 pounds (454 kg).  The measure is used in making comparisons of feed consumption and grazing.

an agent that destroys internal parasites.

a metabolic product of one microorganism or a chemical that in low concentrations is detrimental to activities of other microorganisms.  Penicillin, tetracycline, and streptomycin are antibiotics.  Not effective against viruses.

proteins, found in the blood and other tissues, synthesized in response to an infectious agent (antigen) and capable of recognizing that particular agent in a subsequent infection. Colostrum also contains large amounts of antibodies.

any foreign body that, once in the body, stimulates the production of an antibody. The coat of many bacteria and the structure of many toxin molecules are antigens.

placement of fresh or thawed frozen semen into the female mechanically without normal sexual contact.

refers to feed as it is consumed by an animal, including moisture.

free from bacterial contamination, sterile; used to describe a type of food processing and packaging characterized by non-refrigerated storage and long shelf-life products (see UHT and ultra-pasteurised).

method of filling packages without allowing the entry of microorganisms.  Commonly used for sterile milk products to provide improved keeping quality.

a device for sensing the end of milk flow in the milking machine, for shutting off the milking vacuum, and for retracting the milking unit from the cow's udder.

an indicator of growth calculated as the change in body weight divided by the number of days between the two weight measurements (kg/day).