food chain(redirected from Food chain and webs)
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1. A succession of organisms in an ecological community that are linked to each other through the transfer of energy and nutrients, beginning with an autotrophic organism such as a plant and continuing with each organism being consumed by one higher in the chain.
2. Informal A competitive hierarchy: works high up in the corporate food chain.
Etymology: AS, foda + chaine
an ecological sequence in which the various organisms within a community subsist on organisms lower in the sequence, as the human eats the fish that eats the worm, and so on. Each level within the chain has a fundamental role, and destruction of any one member affects the rest of the chain negatively.
food chaina sequence of organisms arranged in such a way that the second grouping, e.g. HERBIVORES, feeds on the first, e.g. PRIMARY PRODUCERS, and the third, e.g. CARNIVORES, feeds on the second. See Fig. 163 . Each organism in the chain feeds and derives energy from its predecessor in the chain, the relative energy value at each TROPHIC LEVEL often being assessed by the construction of ECOLOGICAL PYRAMIDS. In practice, such simple systems rarely exist and the nutritional relationships between organisms normally constitute a , food web. See Fig. 164 .
materials taken into the body by mouth which provide nourishment in the form of energy or in the building of tissues. Common usage is to use the term in relation to humans and dogs and cats and to use feed for the other animals but the rule is not absolute. See also diet, ration, feed.
nonfood materials added to a diet to enhance or limit a body function, e.g. growth, to control infection or to physically alter the food to facilitate handling or processing or preserving. See food additive.
an immune-mediated reaction to a food or food additive; clinical signs are most commonly demonstrated in the alimentary tract or skin but may affect any system and in any hypersensitivity mode. Commonly diagnosed in dogs, occasionally in horses, but rarely in the other species. Called food hypersensitivity. See also dermatitis, pruritus, angioedema, urticaria, gastroenteritis.
an acute allergic response to a food or food additive, with systemic signs typical of anaphylaxis in the species concerned. See also systemic anaphylaxis.
animals used in the production of food for humans. Includes, in common usage, the species and breeds that also supply fiber and hides for human use. Use of this term has spawned a rash of new knowledge disciplines such as food animal medicine, food animal ophthalmology, and new service areas such as food animal practice.
food borne disease
a disease with food as the source of infection. An example is Eschericia coli 0157:H7 infection of humans via hamburger meat.
the path taken by a raw food product from the farm or other producing unit to the table of the consumer. Includes sale, transport, storage, processing, packaging and retail sale and all of the points of risk at which the food may become contaminated or spoiled or corrupted in some way.
include bacteria, parasites and toxic residues.
food conversion ratio
efficiency in converting the food into energy or tissue; a characteristic of the food relating largely to digestibility.
foods of approximately equivalent levels of energy, proteins, fats and carbohydrates, which may be exchanged or substituted in a diet without significant alteration to its nutritional balance.
see generic pet food.
see food allergy (above).
an adverse reaction to ingested food by an individual, not mediated by immune mechanisms; may be due to an enzyme defect.
amount of food taken in a unit of time, usually daily.
an abnormal physiologic response to food which is not immune-mediated.
the content, purity and public health connotations of animal foods are usually controlled by local legislation.
those commercially formulated and prepared; includes stock feeds, particularly supplements and pellets, canned and dry dog and cat foods.
inert material included in food to measure speed of passage of food through alimentary tract.
usually refers to commercially prepared food such as canned, semimoist, dry, kibbled, biscuits, loaves, and butcher's scraps in various forms provided for dogs and cats.
usual in livestock, but in carnivores it refers to mixed-source diets with a high plant-origin carbohydrate content; a common formula in commercially prepared pet foods.
a group of acute illnesses due to ingestion of a specific toxin in the food. Usually causes gastroenteritis and vomiting and diarrhea.
food refusal syndrome
the many types of food items owners and trainers use to reward their dogs or cats for behavior that pleases them; may be a part of training and behavior modification programs, but is often done simply as a result of the owner's affection for the pet.
food specific dynamic action
see specific dynamic action.
may be the result of toxins or microorganisms contaminating the food or excessive levels of a nutrient, such as vitamin A.