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

Abstract

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.

Feeding laying hens docosa hexaenoic acid-rich microalgae oil at 40 g/kg diet causes hypotriglyceridemia, depresses egg production, and attenuates expression of key genes affecting hepatic triglyceride synthesis and secretion, but is rescued by dietary co-supplementation of high-oleic sunflower oil

“…Microalgae biomass and oils have emerged as viable alternatives to fish oil for the enrichment of eggs and poultry meat with VLC n-3 PUFA ( Cheng et al, 2004 ; Cachaldora et al, 2005 , 2008 ; Lemahieu et al, 2013 ; Neijat et al, 2016 ; Wu et al, 2019 ; Moran et al, 2019 , 2020 ; Feng et al, 2020 ; Liu et al, 2020 ; Światkiewicz et al, 2020 ). However, in contrast to the present findings, all of the above researchers, as well as Gao et al (2021) who recently reviewed this topic, reported that feeding hens DHA-rich MAO or algal biomass did not negatively affect egg weight, yolk weight, or egg production. However, the inclusion of DHA-rich MAO in the diets of laying hens has been reported to produce an off-flavor in eggs often described as “fishy” (Swiatkiewicz et al, 2020 ) which can lead to reduced consumer acceptance.…”

“…However, they observed no effects of feeding hens 30 g/kg of fish oil on egg production or yolk weights as a relative percentage of egg weights and, in a second experiment, hens fed 20 g/kg of fish oil had normal liver, ovary, and oviduct weights. Other researchers have reported that fish oil feeding impaired hen productive performance (reviewed by Fraeye et al, 2012 ; Gao et al, 2021 ) but none reported a complete cessation of egg production, a reduction in circulating triglycerides to the degree observed in the present study, or effects on the hepatic expression of key genes involved in triglyceride and VLDL synthesis or secretion (discussed below).…”

“…However, the inclusion of DHA-rich MAO in the diets of laying hens has been reported to produce an off-flavor in eggs often described as “fishy” (Swiatkiewicz et al, 2020 ) which can lead to reduced consumer acceptance. Based on the reports of Fraeye et al (2012) and Swiatkiewicz et al ( 2020 ), Gao et al (2021) concluded that the dietary inclusion of MAO at more than 25 g/kg will impart negative sensory characteristics in eggs. Feng et al (2020) suggested that, in order to obtain eggs with acceptable sensory properties, dietary DHA supplementation from MAO should not exceed 6.64 mg/g (equal to 13.22 g/kg dietary MAO oil, since the MAO oil used in their study contained 502 mg DHA/g oil), and could result in production of eggs containing as much as 261 mg of DHA/yolk.…”

Effects of Oil Types and Fat Concentrations on Production Performance, Egg Quality, and Antioxidant Capacity of Laying Hens

“…The mixed oil includes different oils according to a defined ratio. The effects of oils on the production performance and egg quality of laying hens have been reported several times [8][9][10][11]. Numerous evidence has shown that under high-temperature conditions, the addition of appropriate amounts of soybean oil to the diet of laying hens, alleviated heat stress and improved egg production and feed conversion ratio, without significant adverse effects on egg weight [12,13].…”

A comparative study on the effects of hemp seed oil versus four different UFA-rich seed oils in the diets of laying hens on egg production, egg quality and yolk fatty acids

“…Lipids are concentrated sources of energy and are used in poultry nutrition to improve energy stability, palatability, and physical quality of the feed. During the peak phase of laying hens, the intensity of lipid metabolism in the body increases, and the oils in the feed enter the body of the eggs via the ovaries (Gao et al 2021). The vegetable oils commonly used in feed are rich in PUFAs (polyunsaturated fatty acids) and the lipids in the egg yolk come mainly from the oils in the feed.…”