The obligatory carnivorous nature of cats probably emerged as part of the slow adaptational process of these animals in becoming efficient predators rather than the result of a specific dietary requirement. Loss of the ability to produce needed nutrients from plant precursors was peripheral to this evolutionary change, but a lasting effect of it.
As a result, present-day cats must meet their nutritional needs in the context of specialized requirements for dietary fat and other nutrients. These needs are most readily met by consumption of other mammalian tissues. High dietary concentrations of protein and special requirements for arginine, taurine, and retinol uniquely characterize feline nutrition. Like other mammals, cats cannot synthesize the essential fatty acid (EFA), linoleic acid (18:2n-6; LA).
However, unlike other mammals, cats also have a limited capacity to synthesize arachidonic acid (20:n-6; AA) from LA and, similarly, eicosapentaenoic acid (20%-3; EPA) and docosahexaenoic acid (22:6n-3; DHA) from or-linolenic acid (1 8:3n-3; ALA). These features of fatty acid metabolism underscore the reliance of cats on other mammals to make these important fatty acids for them. The provision of the dietary EFA to domestic cats (Felis catus) is of interest to veterinarians and animal nutritionists, especially in view of their domestication and role as exclusive household companions. Among other members of the Felidae family, comparative differences are also of interest, not only because optimal nutritional care of captive zoological species must be provided, but also because reproductive performance depends on adequacy of the EFA.
The importance of this latter concept with respect to endangered species such as the cheetah (Acinonyx jubutus) needs little added emphasis. Although most studies of feline fatty acid metabolism have been conducted in Felis catus, opportunities to investigate this topic in other species, when presented, have furthered our understanding of the unique lipid metabolic pathways of the order Carnivora. Results of recent studies in cheetahs from our laboratory are the focus of the present discussion, along with a review of fatty acid metabolism in cats.
Evidence has been obtained that fatty acid metabolism of cheetahs is similar to that of domestic cats and lions. And future collaborative studies will be needed to further our understanding of lipid metabolism in the big cats.
PMID 9483667
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