The effect of replacing soya bean oil with glycerol in diets on performance, egg quality and egg fatty acid composition in laying hens

Abstract

The objective of this experiment was to replace soya bean oil with glycerol in laying hen diets and assess the change's effect on performance, parameters of egg quality and the egg fatty acid profile. A total of 60 44-week-old Hy-Line W36 laying hens were distributed according to a completely randomised experimental design into four treatments consisting of glycerol substitutions for soya bean oil dietary at varying inclusion levels (0%, 25%, 50% and 75%), with five replicates of three birds each. Dietary treatments had no significant effect on BW change, egg production, feed intake, feed conversion ratio, egg weight and egg mass of laying hens. The inclusion of glycerol in the diet of laying hens had no significant effect on egg specific gravity, eggshell breaking strength, eggshell weight, eggshell thickness, egg shape index, albumen index, yolk index, haugh unit, albumen pH, yolk pH and egg yolk colour values. The inclusion of glycerol in the diet of laying hens had no significant effect on palmitic, palmitoleic, stearic, oleic and linolenic acid contents of the egg yolk. The linoleic acid and polyunsaturated fatty acid contents of the egg yolk significantly decreased with the higher levels of dietary glycerol supplementation ( P < 0.05). The results of this study show that it is possible to replace 75% of soya bean oil (4.5% in diet) with glycerol.Keywords: crude oil, glycerol, performance, egg quality, laying hens ImplicationsAlthough glycerol, as a by-product of biodiesel production, can be an attractive alternative energy source for poultry diets, there is a need to determine what level of glycerol could be used in laying hen diets. Its effect on performance, egg quality and egg yolk fatty acid composition should be investigated. According to the results of this study, 75% of soya bean oil can be replaced by glycerol without a negative effect on performance and egg quality in laying hens. However, high level glycerol in the diets potentially decrease PUFA and linoleic acid percentages in the egg yolk.

Crude Glycerin and Energy Density of Diets for Growing, Pre-Lay and Pre-Peak Backcob Brown Egg-Laying Hens

“…Similarly, the physical characteristics of the eggs were not affected by the experimental treatments (results not presented), which on average, recorded the following values: 0.41 mm in shell thickness, 11.9 in color score, 5.95 mm in albumin height and 89.3 Haugh units. Similar to what was found in this study, the literature concludes that shell thickness, yolk color or the height of the albumin of the eggs are not affected by the levels of glycerin inclusion in the diets (Swiatkiewicz & Koreleski, 2009Boso et al, 2013Duarte et al, 2014;Mandalawi et al, 2015;Cufadar et al, 2016;Fontinele et al, 2017).…”

“…There are no reports in the literature of the dragging effect of glycerin consumption during the transition period on the subsequent performance of egglaying hens. However, research evaluating glycerin consumption on the productive response of egg-laying hens concludes, in accordance with what was found after the egg-laying peak, that the use of this co-product in diets does not affect feed consumption, not even when it is included in the formulation of diets (Swiatkiewicz & Koreleski, 2009;Boso et al, 2013;Mandalawi et al, 2015) or when it is used to replace oil in the formulation (Cufadar et al, 2016;Kanbur et al, 2017). The previous result has also been found in egglaying quails (Erol et al, 2009;Ghayas et al, 2017).…”

“…Similarly, the use of this resource does not affect the percentage of egg-laying or the weight of an egg of egg-laying hens, when inclusions are lower than 7.5% (Swiatkiewicz & Koreleski, 2009;Yalcin et al, 2010;Duarte et al, 2014, Mandalawi et al, 2015 or when up to 75% of the energy contribution of oils is replaced by glycerin (Cufadar et al, 2016;Kanbur et al, 2017). In egg-laying quails, the use of diets with inclusions of up to 10% glycerin did not affect the percentage of egg-laying or egg weight (Erol et al, 2009;Ghayas et al, 2017).…”

“…Glycerol, the main component of glycerin, is a molecule that has a rapid intestinal absorption (Kato et al, 2004), and due to the low caloric increaseit has a high net or effective energy value (AVINESP, 2014). In egg-laying hens this co-product has been used at levels of up to 15% for short periods (Lammers et al, 2008;Nemeth et al, 2013) or at 7.5% for several weeks in the egg-laying cycle (Boso et al, 2013;Cufadar et al, 2016).…”

Supplementary n-3 fatty acids sources on performance and formation of omega-3 in egg of laying hens: a meta-analysis

“…In addition, the strain, length of feeding trials, and feed additive incorporation such as acidifier, enzyme, and antioxidants might also affected lipid metabolism and the output of DHA in eggs ( Jia et al., 2008 ; Attia et al., 2013 ; Pérez et al., 2021 ; Lee et al., 2021 ). On the other hand, the effects of feeding hens with FA sources on production performance are conflicting, that is, there was a decrease in egg production ( EP ) and egg weight ( EW ) ( Cufadar et al., 2016 ; Aguillón-Páez et al., 2020 ) where other experiments reported an increased on EP and EW ( Dong et al., 2018 ; Westbrook and Cherian, 2019 ) and others mostly reported no effects on production parameters ( Huang et al., 2018 , 2020 ; Moran et al., 2019 ; Kralik et al., 2021 ).…”