Age of Laying Hens Significantly Influences the Content of Nutritionally Vital Lipophilic Compounds in Eggs

Comparison of Fatty Acid Profile in Egg Yolk from Late-Age Hens Housed in Enriched Cages and in a Free Range System

In recent years, the free-range system for laying hens has increased, driven by societal sensitivity to animal welfare. This study aimed to comparatively analyze the total lipid, cholesterol, and fatty acid composition of egg yolks of late-age laying hens reared in enriched cages (C) and the free-range system (FR). Eggs were collected from Lohmann Brown Classic hens at the 68th, 70th, 72nd, and 74th week of age. The concentrations of total lipids and cholesterol were not affected (p > 0.05) by either factor. Egg yolk from the FR group showed lower (p < 0.01) monounsaturated fatty acids and higher (p < 0.01) polyunsaturated fatty acid (PUFA) compared with that of the C group. From a nutritional point of view, the PUFA n-6/n-3 and the PUFA/SFA ratios of egg yolk from the FR group were favorably lower and higher (p < 0.01) compared with the C one. Conversely, hen age did not affect (p > 0.05) the fatty acid composition of yolks. Interactions between factors were found for total n-3 and n-6 PUFA and the n-6/n-3 ratio (p < 0.01), as well as the thrombogenic index (p < 0.05). In conclusion, the results confirmed that the free-range system may improve the nutritional yolk fatty acid profile and its positive impact on human health.

Carotenoid enrichment in eggs: From biochemistry perspective

The emergence of safe and functional eggs for consumer acceptance has gained focus. The production of carotenoid-enriched eggs has received attention due to its multifunctional biological properties. Nutritional modification of laying hens' diet can be a strategy to produce such eggs. This review presents the chemistry of carotenoids in nature and eggs, the accumulation process of carotenoids into eggs, and the functions of carotenoids in eggs. Our findings showed that carotenoids can be deposited into the egg and contribute to improving its nutritive value. The biosynthesis, chemical structure, and metabolism pathways of carotenoids lead to the deposition of carotenoids into eggs in their original or metabolized forms. Also, some factors modulate the efficiency of carotenoids in fowls before accumulation into eggs. Carotenoid-enriched eggs may be promising, ensuring the availability of highly nutritive eggs. However, further studies are still needed to comprehend the full metabolism process and the extensive functions of carotenoids in eggs.

The Effect of Feeding Laying Hens with Nonindustrial Hemp Seed on the Fatty Acid Profile, Cholesterol Level, and Tocopherol Composition of Egg Yolk

The purpose of this study was to evaluate how cannabis-derived nonindustrial hemp seed (HS) inclusion in laying hen diets, as well as treatment duration, affected the fatty acid (FA) profile, cholesterol level, and tocopherol composition of egg yolks. Ninety-six (n = 96) Lohmann Brown classic laying hens were randomly assigned to one of the four groups: control (standard diet) and HS-containing diets (10% HS, 20% HS, and 30% HS). The study was conducted for a period of 4 months. The findings demonstrated that the FA profile and the tocopherol composition are strongly impacted by the addition of HS to the diet of laying hens (p < 0.05), but the cholesterol content remained unaffected. The increase in the dose of cannabis incorporated into the hen's diet (HS-30% group) led to a significant increase in the amounts of the polyunsaturated fatty acids n-3 and n-6 content of egg yolk. This enrichment was accompanied by a considerable decrease in the n-6/n-3 ratio (p < 0.001) from 8.19 to 4.88, on day 84 of the experiment. The total tocopherol content significantly increased (p < 0.05) from 281.44 (control) to 327.02 μg/g yolk (HS-30%) on day 84. Finally, in the context of warfare, these seeds might be used as a feed additive for laying hens to produce higher nutritive value eggs with affordable prices.

Carotenoids: Dietary Sources, Extraction, Encapsulation, Bioavailability, and Health Benefits-A Review of Recent Advancements

Natural carotenoids (CARs), viz. β-carotene, lutein, astaxanthin, bixin, norbixin, capsanthin, lycopene, canthaxanthin, β-Apo-8-carotenal, zeaxanthin, and β-apo-8-carotenal-ester, are being studied as potential candidates in fields such as food, feed, nutraceuticals, and cosmeceuticals. CAR research is advancing in the following three major fields: (1) CAR production from natural sources and optimization of its downstream processing; (2) encapsulation for enhanced physical and chemical properties; and (3) preclinical, clinical, and epidemiological studies of CARs’ health benefits. This review critically discusses the recent developments in studies of the chemistry and antioxidant activity, marketing trends, dietary sources, extraction, bioaccessibility and bioavailability, encapsulation methods, dietary intake, and health benefits of CARs. Preclinical, clinical, and epidemiological studies on cancer, obesity, type 2 diabetes (T2D), cardiovascular diseases (CVD), osteoporosis, neurodegenerative disease, mental health, eye, and skin health are also discussed.

Production Performance, Egg Quality Characteristics, Fatty Acid Profile and Health Lipid Indices of Produced Eggs, Blood Biochemical Parameters and Welfare Indicators of Laying Hens Fed Dried Olive Pulp

This study aimed to evaluate the long-term dietary effects of dried olive pulp (OP) on production performance, fatty acid profile and health lipid indices and quality characteristics of produced eggs, health and welfare indicators of laying hens. It was carried out in a commercial poultry farm using 300 Isa Brown layers at 23 weeks of age. The hens were randomly and equally divided in six dietary groups CON, OP2, OP3, OP4, OP5 and OP6, according to the inclusion rate of OP in the ration (0%, 2%, 3%, 4%, 5% and 6%, respectively). OP feeding increased the percentage of polyunsaturated fatty acids (PUFA) in eggs, decreased that of saturated fatty acids (SFA) and improved the PUFA to SFA ratio and health lipid indices, as indicated by the decrease of AI and TI and the increase in the h/H ratio of produced eggs, in a dose-dependent way. OP-fed layers presented a lower percentage of broken eggshells compared to controls. No adverse effects on birds’ performance, egg quality traits, health and welfare parameters were observed but a positive impact on Keel Bone Damage (KBD) incidence and belly plumage damage was recorded. OP feeding at the rates of 5% and 6% seems to be beneficial in improving egg nutrition quality.

Comparative characteristics of eggs of chickens of domestic and foreign selection in their diverse age

At this juncture, more and more attention is drawn to the preservation of the gene pool of local breeds of poultry, which have a set of valuable features, including high-quality eggs. In this study, the quality parameters of eggs (egg weight, weight, and proportion of yolk, weight, and proportion of albumen, yolk-albumen ratio, energy value, lipid and fatty acid content in the yolk) of chickens of Ukrainian selection(such hybrids as Plymouth white, Poltava Clay, Birkivska Barvysta and their interbreed hybrids) and foreign commercial crosses (Tetra SL, Tetra H, Super Harko, Lohmann Brown, Highsex White and Brown, High Line W36), at different ages (26, 34, 44 weeks of age) were studied in the comparative aspect. The average egg weight of Ukrainian breeds and hybrids was 51.9 g, 56.5 g, and 61.2 g at the age of 26, 34, and 44 weeks, respectively, in foreign crosses it was much higher - 59 g, 61.2 g, and 64.5 g, respectively (p <0.01). At the same time, there was a probable advantage of the Ukrainian selection bird over the foreign selection bird in the proportion of yolk (by 4.3%, 2.9%, and 4.1% at the age of 26.34 and 44 weeks, respectively), the yolk-albumen ratio (by 0.12, 0.07 and 0.08, respectively) and the energy value of the egg (76, 48 and 60 kJ, respectively). Higher lipid content was found in the egg yolks of domestic chickens in comparison with the foreign hybrid Tetra SL. The total content of saturated and unsaturated fatty acids in the egg yolks in hens of local breeds is higher than in foreign cross. High-quality characteristics of eggs of local breeds and populations are evidence of the presence of a valuable set of genes that require comprehensive study, preservation, and use in the creation of new selectively significant forms.