Delving into vitamin A supplementation in poultry nutrition: current knowledge, functional effects, and practical implications
Yauheni Shastak, Wolf Pelletier
Abstract
SUMMARYVitamin A, also known as retinol, is crucial for maintaining various physiological functions, including vision, immunity, epithelial cell growth and differentiation, reproduction, and bone development. Discussions surrounding retinol in commercial poultry farming have recently emerged due to its significant biological importance, as well as concerns regarding its cost and susceptibility to oxidation in both pure form and premixes. Insufficient vitamin A in avian species can lead to reduced performance, increased susceptibility to infectious diseases, and reproductive disorders. Determining the optimal supply of vitamin A poses a challenging task. Poultry’s requirements for retinol depend on factors such as physiological state, age, health, nutritional status, and function. Scientific committees like the National Academies of Sciences, Engineering, and Medicine (NASEM, formerly National Research Council) or Gesellschaft für Ernährungsphysiologie (GfE) provide requirement estimates (NASEM) or allowances (GfE) as foundations for practical considerations. However, when applied in commercial farming scenarios, extrapolating requirement estimates and allowances from controlled research environments may entail intrinsic limitations. Therefore, developing a comprehensive understanding of the effects of supplemental vitamin A on poultry health and metabolism is essential for formulating balanced diets and achieving optimal performance in commercial settings. The objective of this review is to provide an in-depth analysis of this complex and relatively unexplored topic.