The effects of dietary cottonseed meal and oil supplementation on laying performance and egg quality of laying hens

Abstract

Cottonseed meal (CSM) and cottonseed oil (CSO), two cottonseed products, are rich in protein and lipids, respectively, but their use is limited by antinutritional factors in the products. This study investigated the effect of different dietary levels of CSM and CSO supplementation on the laying performance and egg quality of laying hens. A total of 162 24‐week‐old Hy‐Line brown laying hens were randomly assigned to diets supplemented with 0, 6%, or 12% CSM and 0, 2%, or 4% CSO in a 3 × 3 factorial design. During the 8‐week feeding trial, laying performance and egg quality parameters were measured weekly. Furthermore, a texture profile analysis (TPA) of the egg yolks was conducted, and the fatty acid profiles and protein composition of the yolks were measured to further determine egg quality. CSM supplementation decreased ( p < 0.01) egg production and feed efficiency and increased ( p < 0.01) yolk color, eggshell rate, and shell thickness, but had no significant effects on the TPA parameters, fatty acid profiles, and protein components of egg yolks. CSO supplementation resulted in decreases ( p < 0.01) in egg production, egg weight, and feed efficiency and an increase ( p < 0.01) in yolk color. In addition, CSO supplementation with two weeks of cold storage changed the physical properties of boiled egg yolks, as indicated by increased ( p < 0.01) hardness, springiness, cohesiveness, and chewiness. Furthermore, 4% CSO supplementation increased the ratio of saturated/monounsaturated fatty acids (SAFA/MUFA) and the protein content of egg yolks, which was accompanied by a modified protein composition. These results indicate that CSM supplementation reduces laying performance and egg quality, and CSO supplementation decreases laying performance and results in egg yolk hardening by modifying its components.

Effects of Dietary Cottonseed Oil and Cottonseed Meal Supplementation on Liver Lipid Content, Fatty Acid Profile and Hepatic Function in Laying Hens

“…The level of ALT in hens’ serum was dropped by feeding CSO, while the TP and ALB were markedly increased, which commonly indicates improved hepatic function [ 35 ]. However, the data about performances of the laying hens ( Table S4 ) had been published in our previous research [ 12 ], and it showed that a high level of CSO inclusion impaired the laying hen performances, such as decreased egg production, reduced egg weight, and low feed conversion rate. A previous study also reported the growth retardation and moderate liver histological damage of male New Zealand rabbits fed a diet containing CPFAs [ 36 ].…”

“…The high level of oil residue in the CSM would lead to increased intake of CPFAs in animals. Meanwhile, in previous trials conducted in our laboratory, it was also found that either high levels of CSM or CSO inclusion in diets had adverse effects on the laying performance of hens and the fatty acid profile of their eggs [ 11 , 12 ]. These adverse effects were mostly all linked to the alteration of lipid metabolism in the hen liver.…”

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

“…Cottonseed oil (CSO) is mainly composed of linoleic acid (52%), palmitic acid (24%), and oleic acid (22%) [ 101 ] and is also rich in fat-soluble vitamins; CSO is often used as an energy source in feed. In general, CSO is a high-quality edible vegetable oil with a high nutritional value and low cost.…”

“…CSO may also be enriched in the egg yolk through blood transport, leading to an increase in the HDL/LDL ratio in the egg yolk and a change in the ratio of fatty acids in the egg yolk, which results in a hardening of the egg yolk and the formation of a “rubber egg”. Mu et al [ 101 ] showed that the addition of 2% CSO to the diet of laying hens could harden the yolk and produce “rubber eggs”, thereby affecting the taste of the eggs; the addition of CSO to the diet (58 mg/kg ≤ CPFA ≤ 116.0 mg/kg) slightly increases the yolk color and significantly reduces the laying rate, egg weight, and FCR of laying hens. Traditional egg quality indicators, such as the egg yolk index, HU, and albumen height, do not effectively represent the egg quality of rubber eggs, which illustrates the limitations of traditional egg quality indicators.…”

“…CPFA also causes pink discoloration of yolk spots and albumen, thus deteriorating the internal quality of the eggs [ 168 ]. The FG content is related to adverse reactions such as decreased production performance, a decreased FCR, discoloration of the egg yolk, and decreased hatchability [ 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 159 , 160 , 161 , 162 , 163 , 164 , 166 , 167 , 168 , 171 ]. Therefore, the EU and other countries have issued standard limits for the FG content in various feed ingredients and different animal feed products, and the standard stipulates that the amount of FG added to laying hen diets should not exceed 20 mg/kg.…”