Mineral content of eggs differs with hen strain, age, and rearing environment

Housing and dietary effects on production performance, quality index, and chemical composition of Japanese quail eggs

Quail housing and diet significantly impact egg yield and quality. This study assessed the impact of diets and housing arrangements on Japanese quail's egg production, egg index, and quality. In two trials, birds were reared in cages and on the floor with a commercial layer diet (CLD), and an experimental diet (ED) for 32 weeks. Compared to floor-reared birds, cage birds achieved 50% egg production and sexual maturity first. With dietary effects, the CLD diet showed similar results. Furthermore, their feed efficiency, hen house egg production (HHEP), and hen day egg production (HDEP) were significantly higher in cage birds that consumed CLD. Bird livability was unaffected by the housing system, while birds fed CLD had longer lifespans. The housing system had no discernible effects on egg dry matter (DM), crude protein (CP), crude fat (CF), or ash percentage. Nevertheless, the egg albumen's DM, CP, ash%, yolk's DM, CP, and CF were greater in the birds fed CLD. Barring shell thickness, weight, and Haugh unit, birds raised in cages exhibited higher egg exterior index values. Besides the yolk ratio, yolk index, and albumen weight ratio, birds given CLD exhibited enhanced egg interior quality. Ultimately, the most optimal egg production performance, improved egg quality, and prolonged lifespan of Japanese quail were obtained with cage raising and feeding practices utilizing CLD.

Using low-protein diet in egg production for win-win of productivity and environmental benefits should be prudent: Evidence from pilot test

A shortage of feed protein resources restricts poultry productivity. Key strategies to alleviate this problem include improvements to the structure of the gut microbiota by the appropriate intake of high-quality protein, improvements to the comprehensive protein utilization rate, and reducing the consumption of protein raw materials. In addition, damage to the environment caused by nitrogen emissions needs to be reduced. The aim of the study was to evaluate the effects of dietary protein levels on laying performance, host metabolism, ovarian health, nitrogen emissions, and the gut microbial structure and function of laying hens. In total, 360 hens at the age of 38 weeks were randomly allotted four treatments. Each of the groups consisted of nine replicates, with 10 birds per replicate, used for 12 weeks of study. Dietary protein levels of the four groups were 13.85 %, 14.41 %, 15.63 %, and 16.30 %. Results revealed that, compared with the 13.85 % crude protein (CP) group, the 15.63 % CP group experienced significantly enhanced final body weight, average daily gain, egg production, and egg mass. Compared with the 16.30 % CP group, the other groups' serum concentrations of immunoglobulin G (IgG) and immunoglobulin M (IgM) were significantly reduced. Compared with the 16.30 % CP group, the 13.85 % and 15.63 % groups had increased CP utilization rates but reduced nitrogen emission rate, and daily per egg and per kilogram egg nitrogen emissions rose with increased dietary protein levels. Compared to the 13.85 % and 14.41 % CP groups, the 16.30 % CP group exhibited a significant increase in the expression of genes related to amino acids and carbohydrate metabolic pathways. According to the linear discriminant analysis effect size diagram, the predominant bacteria in the 15.63 % CP group (e.g., Subdoligranulum, and Ruminococcaceae_UCG-013) were significantly related to CP utilization. The results of this study emphasize that production performance is significantly reduced when protein levels are too low, whereas too high protein levels lead to gut microbiota imbalance and a reduction in the utilization efficiency of nutrients. Therefore, on the premise of ensuring the health of hens, the structure of the gut microbiota can be improved by appropriately reducing protein levels, which helps to balance the relationships among host health, productivity, resources, and the environment.

Non-Destructive Classification of Organic and Conventional Hens' Eggs Using Near-Infrared Hyperspectral Imaging

Eggs that are produced using organic methods retail at higher prices than those produced using conventional methods, but they cannot be differentiated reliably using visual methods. Eggs can therefore be fraudulently mislabeled in order to increase their wholesale and retail prices. The objective of this research was therefore to test near-infrared hyperspectral imaging (NIR-HSI) to identify whether an egg has been produced using organic or conventional methods. A total of 210 organic and 210 conventional fresh eggs were individually scanned using NIR-HSI to obtain absorbance spectra for discrimination analysis. The physical properties of each egg were also measured non-destructively in order to analyze the performance of discrimination compared with those of the NIR-HSI spectral data. Principal component analysis (PCA) showed variation for PC1 and PC2 of 57% and 23% and 94% and 4% based on physical properties and the spectral data, respectively. The best results of the classification using NIR-HSI spectral data obtained an accuracy of 96.03% and an error rate of 3.97% via partial least squares-discriminant analysis (PLS-DA), indicating the possibility that NIR-HSI could be successfully used to rapidly, reliably, and non-destructively differentiate between eggs that had been produced using organic methods from eggs that had been produced using conventional methods.

Blood biochemical parameters and organs development of brown layers fed reduced dietary protein levels in two rearing systems

Objective

An experiment was conducted to evaluate the effect of different levels of crude protein (CP) and two rearing systems (cage and floor), on blood parameters and digestive and reproductive organ development of brown laying hens.

Methods

A total of 400 Hisex Brown laying hens between 30 and 45 weeks of age were distributed in a completely randomized design and a 2×4 factorial arrangement, with main effects including two rearing systems (cage and floor) and levels of CP (140, 150, 160, and 180 g/kg), in a total of eight treatments and five replicates of 10 birds each with initial body weight of 1,877 g (laying hen in cage) and 1,866 g (laying hens in floor). The parameters evaluated were plasma total protein, albumin, uric acid, total cholesterol, relative weights of oviduct, abdominal fat, liver, gizzard, crest and dewlap, length of small intestine and oviduct.

Results

The blood parameters were similar in birds reared in cage and floor systems. The birds reared on the floor showed greater small intestine and oviduct weight (%) and lower liver and pancreas weight (%). A significant interaction was observed between factors for the relative gizzard, crest and dewlap weight, serum protein, uric acid, and total cholesterol (P<0.05). The diets with 140 g/kg CP resulted in lower serum protein and lower cholesterol in birds reared in floor system, while birds reared in cage system showed no effect of CP on both parameters. Birds reared in cage and fed with 140 and 150 g/kg CP presented lower uric acid. The group of birds reared in floor system fed 180 g/kg had greater uric acid.

Conclusion

The dietary protein level can be reduced up to 140 g/kg for Hisex Brown hens (30 to 45 weeks of age) without an important effect on metabolic profile and organ development in both rearing systems.

Egg Yolk Antioxidants Profiles: Effect of Diet Supplementation with Linseeds and Tomato-Red Pepper Mixture before and after Storage

This study evaluated the effect of dietary incorporation of linseed alone or along with dried tomato paste-pepper powder mix on egg physical characteristics, antioxidant profiles, lipid oxidative status, and yolk coloration before and after storage at 4 °C for one month. Sixty Novogen White laying hens, 27 weeks-old, were divided into three groups and given 100 g/hen/day of a standard diet (C), standard diet containing 4.5% of ground linseed (L), linseed diet containing 1% of dried tomato paste and 1% of sweet red pepper (LTP). Linseeds increased (p < 0.05) egg yolk antioxidant capacity but not lipid oxidative stability (p > 0.05). However, dietary inclusion of LTP did not improve fresh egg yolk antioxidant activity and lipid oxidation stability (p > 0.05). With reference to the stored eggs, only antioxidant activity measured by phosphomolybdenum reduction and lipid oxidative stability were influenced (p < 0.05) by the dietary treatment. Fresh egg yolk of hens fed on linseeds tended to have a slightly more yellow, redder, and less light color than the eggs of hens fed with the control diet. Dietary supplementation of LTP increased (p < 0.05) the Roche yolk color fan (RYCF) score and redness (a*) and decreased (p < 0.05) lightness (L*) without affecting (p > 0.05) saturation (C*). Storage of hens’ eggs fed on the control diet did not influence (p > 0.05) yolk color.

Content of selected inorganic compounds in the eggs of hens kept in two different systems: organic and battery cage

Recent years have seen increased interest in the influence of bioactive dietary components on human genes and gene expression. A good source of many bioactive substances is the chicken egg. The egg is considered to be an excellent food provided by nature. It is a good source of nutrients such as vitamins A, B2, B6, B12, D, E and K, as well as elements including phosphorus, selenium, iron, zinc, magnesium and calcium. The research material use in this study consisted of eggs from hens kept in two different systems: organic and battery cages. The content of calcium (Ca), magnesium (Mg) and zinc (Zn) was determined in the egg contents - in the yolk and white respectively. The content of elements was determined by atomic absorption spectrometry (AAS) using an AA280 FS spectrometer with the automatic dilution of standards and samples. The eggs from the organically raised hens had a higher calcium, magnesium and zinc content. The greater variation in the Ca, Mg and Zn content in the organic eggs is due to the more individualized feeding system. The rearing system of the hens significantly affects the concentration of elements in the egg. The results of this research indicate that eggs from organic farming systems have a richer chemical composition in terms of the content of nutrients such as calcium, magnesium and zinc compared with eggs obtained from caged hens. Therefore, consumers purchasing eggs should consider the system in which the hens were reared, as eggs can be a valuable source of these elements in the diet.

Effect of Dietary Incorporation of Linseed Alone or Together with Tomato-Red Pepper Mix on Laying Hens' Egg Yolk Fatty Acids Profile and Health Lipid Indexes

This study evaluated the effect of linseed incorporation in laying hens’ feed (alone or along with a tomato-red pepper mix) on laying hens’ egg yolk fatty acids profile, as well as on their atherogenic (IA) and thrombogenic (IT) health lipid indexes, and the ratio between the hypocholesterolemic and hypercholesterolemic fatty acids (HH). Sixty 27 weeks-old Novogen White laying hens were divided into three groups and given 100 g/hen/day of a standard diet (Control, C) containing 4.5% of ground linseed (Linseed diet, L), containing 1% of dried tomato paste and 1% sweet red pepper (Lineseeds-Tomato-Pepper, LTP). The linseed dietary inclusion significantly reduced the egg yolk content of palmitic acid from 25.41% (C) to 23.43% (L) and that of stearic acid from 14.75% (C) to 12.52% (L). Feeding 4.5% ground linseed did not affect the egg yolk content of α-Linolenic acid but significantly increased the egg yolk concentration of eicosapentaenoic acid (EPA) from 0.011% (C) to 0.047% (L) and that of docosahexaenoic acid (DHA) from 1.94% (C) to 2.73% (L). The IA and the HH were not affected (p > 0.05) by the dietary addition of linseed, whereas the IT decreased (p < 0.05) from 1.16 (C) to 0.86 (L). Adding tomato-sweet red pepper mix to the linseed-supplemented feed did not affect the measured parameters as compared to the linseed dietary treatment.