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

Sunflower cake associated with crude glycerin in white laying hens diets: Performance and quality, antioxidant activity and lipid oxidation of eggs

The objective of this study was to evaluate the effects of sunflower cake inclusion and its association with crude glycerin in the diet of laying hens. A total of 320 laying hens with 39 weeks of age were distributed in a completely randomized design in a 4 × 2 factorial scheme with 5 replications of 8 birds. The studied factors were 4 inclusion levels of sunflower cake and 2 levels of crude glycerin. The inclusion of 210 g/kg of sunflower cake reduced egg mass and worsened feed conversion, and after the level 70 g/kg there was reduction in yolk coloration and specific density of eggs with or without the addition of glycerin in the diet. The addition of 70 g/kg of crude glycerin reduced the specific density of eggs in all levels of sunflower cake. There was increase in phenolic compounds, antioxidant capacity and antioxidant activity in eggs and reduction in lipid oxidation of yolks from fresh and stored eggs, with the inclusion of sunflower cake. The addition of crude glycerin increased the lipid oxidation of egg yolks. Therefore, it is possible to include up to 140 g/kg sunflower cake in the diet of laying hens, with or without crude glycerin, without impairing performance and egg quality, obtaining higher antioxidant capacity of eggs and lower lipid oxidation in yolks from fresh and stored eggs. The inclusion of 70 g/kg crude glycerin does not affect laying hens performance, however, it worsens shell quality and increases lipid oxidation in the liver and egg yolks.

Natural Products of Plants and Animal Origin Improve Albumen Quality of Chicken Eggs

Albumen quality is recognized as one of the major yardsticks in measuring egg quality. The elasticity of thick albumen, a strong bond in the ovomucin-lysozyme complex, and excellent biological properties are indicators of high-quality albumen. The albumen quality prior to egg storage contribute to enhance egg’s shelf life and economic value. Evidence suggests that albumen quality can deteriorate due to changes in albumen structure, such as the degradation of β-ovomucin subunit and O-glyosidic bonds, the collapse of the ovomucin-lysozyme complex, and a decrease in albumen protein-protein interaction. Using organic minerals, natural plants and animal products with antioxidant and antimicrobial properties, high biological value, no residue effect and toxicity risk could improve albumen quality. These natural products (e.g., tea polyphenols, marigold extract, magnolol, essential oils, Upro (small peptide), yeast cell wall, Bacillus species, a purified amino acid from animal blood, and pumpkin seed meal) are bio-fortified into eggs, thus enhancing the biological and technological function of the albumen. Multiple strategies to meeting laying hens’ metabolic requirements and improvement in albumen quality are described in this review, including the use of amino acids, vitamins, minerals, essential oils, prebiotics, probiotics, organic trace elements, and phytogenic as feed additives. From this analysis, natural products can improve animal health and consequently albumen quality. Future research should focus on effects of these natural products in extending shelf life of the albumen during storage and at different storage conditions. Research in that direction may provide insight into albumen quality and its biological value in fresh and stored eggs.

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

A meta-analysis was performed to evaluate the effects of supplementary n-3 polyunsaturated fatty acids (PUFA) sources in the diet on the formation of some important n-3 PUFA contents in eggs and to assess factors contributing to the conversion efficiency of omega-3 in laying hens. A dataset was constructed from 34 studies examining the impact of dietary inclusion with ingredients rich in n-3 PUFA on fatty acids profile and production performance of laying hens. The eligibility criteria were developed to obtain studies reporting required information with sufficient quality. The mixed model methodology was employed where the “study” was set as random effects and fatty acid (FA) supplements as fixed effects. Several factors were included in the models as covariates. Discrete analysis for sources of FA was also performed to compare their effects on FA formation in eggs. Significant linear positive associations were observed between the concentration of α-linolenic acid (ALA), total n-3 PUFA, and the ratio of linoleic acid (LA) to ALA (LA/ALA) in diets with the formation of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), total n-3 PUFA, and n6/n3 ratio in egg (P < 0.05) with different magnitudes. ALA and total n-3 PUFAs concentration had no relationship with cholesterol concentration, feed intake, and egg weight. Prediction models for DHA formation was higher for ALA as predictor variables (slope = 0.482; R² = 0.684) than n-3 PUFAs (slopes = 0.998, R² = 0.628). Significant interactions were found on the level of ALA × FA sources and n-3 PUFA × FA sources. Fish oil (P = 0.0148, R² = 0.732) improved the prediction equation to estimate DHA formation. To conclude, levels of ALA, n-3 PUFA, and the ratio of LA/ALA can be used as predictor variables to estimate the formation of n-3 fatty acids in eggs. It was confirmed that although all n-3 FA sources had a positive correlation on DHA and n-3 PUFA deposition, however, fish oil showed the highest prediction model for DHA formation across all FA sources included in the dataset.

Evaluating the Effect of a Brewery By-Product as Feed Supplementation on the Quality of Eggs by Means of a Human Panel and E-Tongue and E-Nose Analysis

The objective of our research was to evaluate the possible alteration of the organoleptic properties of eggs produced by hens (Lohmann Brown-Classic) fed with diets containing different doses of an industrial by-product enriched with organic zinc (Zincoppyeast, ZP): Control 0%, ZP 2.5%, and ZP 5.0%. Eggs were collected after 30 days (batch 1) and 60 days (batch 2) of feeding with the experimental diets and subjected to chemical, microbiological, human sensory, e-nose, and e-tongue analyses. There was no significant difference among the microbiological status of eggs of the three groups, but there were significant differences (p < 0.05) in the fat (9.5% vs. 9.3%) and protein contents (12.7% vs. 13.4%) of the Control and ZP 5.0% groups, respectively. Human sensory analysis showed no clear change in the organoleptic characteristics of the eggs. Using linear discriminant analysis (LDA), the e-tongue could recognize the three groups of eggs in batch 1 and batch 2 with 95.9% and 100% accuracy and had a prediction accuracy of 64.8% and 56.2%, respectively. When the eggs were incubating at 50 °C or 80 °C before the e-nose analysis, the groups of eggs could be recognized with 98.0% and 82.7% accuracy, and predicted with 68.5% and 62.2% accuracy, respectively, using principal component analysis-based discriminant analysis (PCA–DA). The aroma compounds and respective sensory descriptors showing changes among the different groups of eggs (batch, storage, and feeding) were identified based on the e-nose analysis. The supplementation of laying hens’ feed with the investigated industrial by-product can be applied without any substantial effect on egg quality, which can, however, be detected with advanced analytical methods.

The effects of high-oleic peanuts as an alternate feed ingredient on performance, ileal digestibility, apparent metabolizable energy, and histology of the small intestine in laying hens

We aimed to determine the effects of feeding a high-oleic peanut (HOPN) diet to egg-producing laying hens on egg quality, digestibility, and feed conversion. Three isonitrogenous and isocaloric dietary treatments were formulated with 1) Control diet (CON)-a corn-soybean meal conventional diet with 7.8 % added poultry fat, 2) HOPN diet-dietary inclusion of ~20% coarse-ground whole HOPN, and 3) oleic acid (CON-OA) diet-a control diet supplemented with 2.6% oleic fatty acid oil. Ninety-nine 57-wk-old brown Leghorn laying hens were randomly assigned to 33 animals per treatment. Animals were housed individually for 8 wk. Body and feed weights were recorded weekly and feed conversation ratio was calculated. Bi-weekly, shell eggs were analyzed for quality (yolk color, albumen height, and Haugh unit [HU]). Jejunum samples were collected at week 8 for histomorphometric analysis. Analysis of variance was performed on all variables using a general linear mixed model. Laying hens fed the CON-OA diet produced greater number of eggs relative to those fed the HOPN and control diets (P < 0.05). The roche yolk color value was higher (P < 0.001) in eggs from hens fed the HOPN diet. There were no differences in laying hen performance, eggshell color, eggshell strength, eggshell elasticity and egg albumen height, or egg HU, ileal fat digestibility, or villi surface among treatment groups. However, the apparent metabolizable energy (P < 0.01) and ileal protein digestibility (P = 0.02) were greater in laying hens fed the HOPN diet relative to the CON diet. This study suggests that whole unblanched high-oleic peanuts may be an acceptable alternative feed ingredient for laying hens.