Importance of essential fatty acids and their derivatives in poultry.

More than thirty-five years have passed since essential fatty acid requirements were demonstrated for poultry. Subsequent studies were conducted to establish a recommended level of linoleic acid for growing poultry. Although a requirement of 1% linoleic acid is suggested, a critical evaluation of the nutritional and metabolic significance of essential fatty acids is lacking. Perhaps alpha-linolenic acid is also essential, but direct evidence is not yet available. Recent literature indicates that several individual fatty acids, including the polyunsaturates derived from essential fatty acids, are biologically active. Furthermore, the numerous eicosanoids biosynthesized from specific polyunsaturates act as either cellular autocrine or paracrine signaling agents. Formation of eicosanoids is ubiquitous in tissues and organs, and these compounds influence nearly all systems in mammalian species. However, although such compounds have been studied extensively in mammalian systems, the formation of polyunsaturates, the biosynthesis of eicosanoids and the biological effects of these compounds have not been intensely studied in domestic poultry.