Effect of Oils in Feed on the Production Performance and Egg Quality of Laying Hens

Simple Summary Eggs are a valuable source of protein and fat in the human diet. Due to continuous improvement in the production performance of laying hens, the requirements regarding the feed energy of laying hens are increasing. Oils, which are the main energy sources in feed, exert a substantial effect on the production performance and egg quality of laying hens. In this review, we discuss the classification of oils commonly used in the diets of laying hens and the process of lipid metabolism in laying hens. We further look at the effects of adding different oils on the nutritional composition of eggs with a focus on the mechanism through which dietary oils affect the production performance and egg quality of laying hens, the effects of adding different types of animal and plant oils to the diets, and the potential effects of different types of oils on the health of laying hens. With the development of a large-scale and intensive production industry, the number of laying hens in China is rapidly increasing. Oils, as an important source of essential fatty acids, can be added to the diet to effectively improve the production performance and absorption of other nutrients. The present review discusses the practical application of different types and qualities of oils in poultry diets and studies the critical effects of these oils on production performance, such as the egg weight, feed intake, feed conversion ratio (FCR), and various egg quality parameters, including the albumen height, Haugh units, yolk color, and saturated/unsaturated fatty acids. This article reviews the effects of different dietary oil sources on the production performance and egg quality of laying hens and their potential functional mechanisms and provides a reference for the selection of different sources of oils to include in the diet with the aim of improving egg production. This review thus provides a reference for the application of oils to the diets of laying hens. Future studies are needed to determine how poultry products can be produced with the appropriate proper oils in the diet and without negative effects on production performance and egg quality.