Abstract
Arachidonic acid, retinol and taurine are known to the cat : felis catus of the genuine flesh-eating animal as nutrient necessity. The required nature of the arachidonic acid depends on deficit of Δ6-desaturase. Therefore arachidonic acid cannot metabolize even if cat take in linoleic acid. Because the required nature of the retinol (vitamin A) deletes dioxygenase in the bowels, cat cannot resolve β-carotene into retinol. Because cat do not have an enzyme composing taurine, it is necessary to take in the taurine which there is only to animal protein. It mean that EPA and DHA cannot metabolize even if the deficit of Δ6-desaturase takes in the linolenic acid of the n-3 fatty acid. It is necessary to take in the mammalian meat which contains them because it cannot metabolize even if the cat of the genuine flesh-eating animal takes in linoleic acid and the linolenic acid of the plant to get arachidonic acid, EPA and DHA. The fish contains arachidonic acid, retinol, and taurine other than EPA and DHA. The photoreceptor of the retina of the cat which a thing looks like in darkness, DHA, retinol and taurine are that is to say necessary for construction and the maintenance of the photoreceptor. The writer suggests a hypothesis that “the cat eats a fish when it cannot take in meat” from the above-mentioned reason.
