maintenance - Condition in which the body is maintained without an increase or decrease in body weight and with no production or work being done.
mammary gland - Gland that secretes milk.
management - Act, art, or manner of managing, handling, controlling, or directing a resource or integrating several resources.
management systems - Methods of systematically organizing information from several resources to make effective management decisions. See also integrated resource management (IRM).
marbling - Flecks of intramuscular fat distributed in muscle tissue. Marbling is usually evaluated in the rib-eye between the twelfth and thirteenth ribs.
MARC - See Meat Animal Research Center (MARC).
margin - (1) "Earnest money" that serves as default protection in a futures transaction. (2) Difference between prices at different levels of the marketing system. (3) Difference between cost and sale price.
marker-assisted selection - A method of genetic evaluation which takes into consideration the DNA marker genotype along with conventional selection procedures.
market class - Cattle grouped according the their use, such as slaughter, feeder, or stocker.
market grade - Cattle grouped within a market class according to their value.
market niche - Segment of consumer demand targeted by a specialized production and marketing plant. Examples include the "white tablecloth" restaurant trade, health foods, and convenience foods.
masculinity - Well-developed secondary sex characteristics in the neck, chest, and shoulders of the bull.
masticate - To chew food.
mastitis - Inflammation of the mammary gland.
maternal - Pertaining to the female (cow or heifer).
maternal first-calf calving ease - Ease with which a sire's daughters calve as first-calf heifers (under 33 months of age). Reported as a ratio or an EPD.
maternal heterosis - Heterosis for those traits influenced by the cow genotype. For example, maternal heterosis of weaning weight refers to the increase in weaning weight from being raised on a crossbred cow rather than a straightbred cow.
maternal traits - All the traits expressed by the cow. A limited definition implies milk and weaning weight production of the cow.
maternal weaning weight - Weaning weight of a bull's daughter's calves. The EPD value predicts the difference in average 205-day weight of a bull's daughter's calves compared to daughters of all other bulls evaluated. It can be calculated by adding one-half of the bull's EPD for weaning weight to his milk EPD.
maturity - An estimation of the chronological age of the animal or carcass.
maverick - Unbranded animal, usually on the range.
M/B or M:B ratio - See muscle-to-bone ratio.
mean - (1) Statistical term for average. (2) Term used to describe cattle having bad behavior.
meat - Tissues of the animal body that are used for food.
Meat Animal Research Center (MARC) - Large U.S. government research center located in Clay Center, NE, that conducts numerous beef cattle research projects.
Meat Export Federation (MEF) - See U.S. Meat Export Federation (MEF).
MEF - See U.S. Meat Export Federation (MEF).
melengestrol acetate (MGA) - Feed additive that suppresses estrus in heifers; used in estrus synchronization and feedlot heifers.
MERCOSUR (Common Market of the South) - A customs union implemented in January 1995, and including Argentina, Brazil, Paraguay, and Uruguay. MERCOSUR represents the culmination of bilateral negotiations started by Argentina and Brazil in 1986.
metabolic body size - Weight of the animal raised to the 3/4-power (W0.75); a figure indicative of metabolic needs and of the feed required to maintain a certain body weight.
metabolism - (1) Sum total of chemical changes in the body, including the "building up" and "breaking down" processes. (2) Transformation by which energy is made available for body uses.
metabolizable energy - Gross energy in the feed minus the sum of energy in the feces, gaseous products of digestion, and energy in the urine. Energy that is made available for body uses.
metritis - Inflammation (infection) of the uterus.
MGA - See melengestrol acetate (MGA).
middle meats - Rib and loin of a beef carcass. These primals generally yield the highest-priced beef cuts.
milk EPD - Estimate of the milking ability of a bull's daughters compared to the average of the daughters of other bulls. Reported in pounds of weaning weight; positive values indicate above-average performance and negative numbers indicate below-average maternal ability. See also expected progeny difference (EPD).
mill feed - Any feed that is subjected to the milling process.
minimum culling level - Selection method in which an animal must meet minimum standards for each trait desired in order to qualify for being retained for breeding purposes.
mites - Very small arachnids that can be parasites of cattle.
morbidity - Measurement of illness; morbidity rate is the number of individuals in a group that become ill during a specified time period.
mortality rate - Number of individuals that die from a disease during a specified time period, usually 1 year.
most probable producing ability (MPPA) - Estimate of a cow's future productivity for a trait (such as progeny weaning weight ratio) based on her past productivity. For example, a cow's MPPA for weaning ratio is calculated from the cow's average progeny weight ratio, the number of her progeny weaning records, and the repeatability of weaning weight.
mouthed - Examination of an animal's teeth.
MPPA - See most probable producing ability (MPPA).
muley - Term used to describe the polled (hornless) condition.
muscle-to-bone (M/B) ratio - Pounds of muscle divided by pounds of bone. For example, 4:1 ratio means that there is 4 lb of muscle to 1 lb of bone (usually on a carcass basis).
muscling - Amount of lean meat in a slaughter animal or carcass. Estimated on the live animal by thickness of forearm muscle or stifle thickness. Ultimately it is the ratio of muscle to bone or lean yield of the carcass after fat and bone are removed.
muzzle - Nose of cattle.
myofibrils - Primary component part of muscle fibers.