Animal Science Terms - R

rBGH or rbST: bST (bovine somatotropin) is a protein hormone that occurs naturally in all dairy cows. Some farmers choose to supplement some of their cows with rbST, also known as bovine growth hormone (rBGH), to help increase milk production. The safety of milk from rbST-supplementedcows has been affirmed and reaffirmed since it was approved for use in the U.S. in the early 1990s

Rabbit: mammal of the family (Leporidae) or the domesticated Old World species (Oryctolagus cuniculus)

Rabbitry: where owners keep their herd of rabbits in separate cages

Rack: (meats term) refers to the rib section of the carcass along the back. This is one of the highest value cuts on a goat and is often used as a roast

Ractopamine: drug that is used as a feed additive to promote leanness in pigs raised for their meat

Raddle (Marker): paint or crayon applied to the male’s chest to mark the females he mates

Ram: intact male sheep that is at least one year of age  

Ram lamb: male sheep that is under 1 year of age

Range: area of land that is populated with native plants species, often never cultivated

Rangeland: large open land area on which livestock wander and graze. The native vegetation is mainly grasses and shrubs

Ration: total feed allowance to an individual during a 24-hour period

Raw Milk: milk that has not been pasteurized before consumption

Repeatability: expression of the same trait at different times in the life of the same individual or the tendency of an individual to repeat its performance e.g. dairy cow in successive lactation

Recessive: genes which have no observable effect unless present in both members of a chromosome pair. See recessive gene

Recessive Gene: gene which must be present on both chromosomes in a pair to show outward signs of a certain characteristic

Rectal Prolapse: a portion of the rectum protrudes from the anus

Red Meat: meat which is colored red when raw and not white when cooked. In the nutritional sciences, red meat includes all mammal meat. Red meat includes the meat of most adult mammals and some fowl (e.g. ducks)

Registered: animal whose birth and ancestry has been recorded by a registry association

Relative feed value: standardized measure of forage quality calculated from acid detergent and neutral detergent fibre contents. Forage with NDF values of 53% and ADF values of 41% represent a value of 100. Forages with values greater than 100 are of higher quality, and forages with a value lower than 100 are of lower quality. Dry matter intake (DMI) and digestible dry matter (DDM) values of forages can be used to calculate RFV or use the formula with ADF and NDF values

Rendering: removing and/or clarifying one substance (e.g., fat, water) from another, either through the use of heat or by pressing and draining a solid residue of cooked material

Replacement Heifers: female dairy animals that are raised with the intent of eventually replacing the cows currently in the milking herd

Reticulum: second compartment of the ruminant’s stomach, which together with the rumen contains microorganisms that digest fiber. The contents are regurgitated for further chewing as part of the cud and has a honey-combed appearance. It is the receptacle for metal foreign objects that is swallowed

Roasted: feed ingredients heated to a desired temperature in an oven for a period of time. Roasting increases the availability of carbohydrates and may reduce protein breakdown in the rumen

Roasters: chickens that are 6-12 months of age weighing 4-7 pounds

Rolled: feed ingredients (grains) passed between a set of rollers, splitting the coarse outer grain shell

Roomy Middled: big barreled, lots of spring in ribs, capacious

Rooster: male chicken over one year of age  

Rotational Grazing: system by which livestock are allotted to a certain grazing or browsing area for a certain period of time before they are moved to another area

Roughage: coarse feed high in fiber, low in energy, low total digestible nutrient feed consisting of coarse bulky plants or plant parts; dry or green feed with over 18% crude fiber. It provides bulk to the diet and promote normal bowel function

Rugged: big and strong

Rump: area between the hip bones and the tail head

Rumen: large first compartment of a ruminant’s stomach containing a microbial population that is capable of breaking down forages and roughages through fermentation

Rumen-degradable protein: portion of ingested protein that is susceptible to digestion by rumen microorganisms; used in the synthesis of microbial protein

Rumen-undegradable protein (RUP): portion of ingested protein that resists rumen degradation and is digested directly in the other stomachs or small intestine; generally a more expensive source of protein

Rumenocentesis (rumen tap): rumen contents are collected by inserting a needle into the rumen

Ruminant: even-toed, hoofed mammals of the suborder (Ruminantia) that have a four-compartment stomach (rumen or paunch, reticulum or honeycomb, omasum or manyplies, and abomasum or true stomach). This digestive system allows the animal to swallow their food quickly and then bring it up again (regurgitate) to chew it slowly and properly digest it (e.g., cattle, deer, camels, etc.)

Rumination: process of regurgitating food to be re-chewed

Runoff: Water from rain, snowmelt or other sources that flows over the land surface and is a major component of the water cycle. Dairy farms take measures to control the amount of runoff from their farms through the use of drainage systems and retention ponds



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