Morphological variation of tail bone among two chicken breeds and their F1 progeny.

Fancy breeds of Japanese indigenous chicken display extensive morphological diversity, particularly in tail feathers. Although marked differences in tail and bone traits have been reported between Tosa-jidori (wild type) and Minohikichabo (rich type) breeds, little is known about the pattern of genetic inheritance in cross experiments. Therefore, this study aimed to investigate the strain and sex effects, and inheritance patterns, in the morphometric variation of pygostyle bones among Tosa-jidori, Minohikichabo, and their F1 hybrids. Five morphological traits, angle of the apex of the pygostyle, pygostyle length, margo cranialis length, tail feather number, and body weight, were evaluated at the adult stage. A significant strain difference was detected in all traits, whereas significant sex differences were observed in only three traits, but not in the angle of the apex of the pygostyle and tail feather number. In F1 hybrids, the angle of the apex of the pygostyle was significantly different to that of Tosa-jidori but not that of Minohikichabo, whereas the pygostyle length and tail number of F1 hybrids were significantly different from those of Minohikichabo but not those of Tosa-jidori. A significant heterosis effect was found in the margo cranialis length and body weight. All five traits showed nonadditive inheritance patterns but varied in each trait between partial dominance (angle of the apex of pygostyle), full dominance (pygostyle length and tail feather number), and over-dominance (margo cranialis length and body weight). Interestingly, different patterns of genetic inheritance in the F1 hybrid were observed at different locations, even within the same pygostyle bone. Using the Japanese indigenous chicken model, these results provide a substantial step toward understanding the genetic architecture of morphology in chickens.

Orientation-Independent-DIC imaging reveals that a transient rise in depletion force contributes to mitotic chromosome condensation.

Genomic information must be faithfully transmitted into two daughter cells during mitosis. To ensure the transmission process, interphase chromatin is further condensed into mitotic chromosomes. Although protein factors like condensins and topoisomerase IIα are involved in the assembly of mitotic chromosomes, the physical bases of the condensation process remain unclear. Depletion force/macromolecular crowding, an effective attractive force that arises between large structures in crowded environments around chromosomes, may contribute to the condensation process. To approach this issue, we investigated the "chromosome milieu" during mitosis of living human cells using orientation-independent-differential interference contrast (OI-DIC) module combined with a confocal laser scanning microscope, which is capable of precisely mapping optical path differences and estimating molecular densities. We found that the molecular density surrounding chromosomes increased with the progression from prometaphase to anaphase, concurring with chromosome condensation. However, the molecular density went down in telophase, when chromosome decondensation began. Changes in the molecular density around chromosomes by hypotonic or hypertonic treatment consistently altered the condensation levels of chromosomes. In vitro, native chromatin was converted into liquid droplets of chromatin in the presence of cations and a macromolecular crowder. Additional crowder made the chromatin droplets stiffer and more solid-like, with further condensation. These results suggest that a transient rise in depletion force, likely triggered by the relocation of macromolecules (proteins, RNAs and others) via nuclear envelope breakdown and also by a subsequent decrease in cell-volumes, contributes to mitotic chromosome condensation, shedding light on a new aspect of the condensation mechanism in living human cells.

New Behavioral Handling Test Reveals Temperament Differences in Native Japanese Chickens.

It is well known in the poultry industry that fear and stress experienced during the handling of day-old chicks in commercial hatcheries can have long-lasting effects on their behavior later in life. These hatchery-related stresses are more intense and complex than those encountered in traditional behavioral tests. Consequently, a single behavioral test may not be sufficient to measure hatchery stresses and chicken temperament. In this study, we developed a new behavioral handling test for day-old chickens, which incorporated concepts from established behavioral tests used with both young and adult birds. The new test assessed 10 behavioral traits, including vocalization frequency and responses to human interaction. It was conducted on 96 two-day-old chicks from seven breeds of native Japanese and Western chickens. The results of the principal component analysis classified chicken temperaments into three distinct categories: bustle, aggression, and timidity. Using these categories, the seven breeds were classified into five groups, each with distinct temperaments. This study highlights the reliability and value of the new handling test in characterizing the temperaments of various chicken breeds and provides insights into the complex behaviors of chickens.

Housing Systems Affect Eggshell Lightness and Free Amino Acid Contents of Egg Albumen in Tosa-Jidori Chickens: A Preliminary Research.

Many countries have gradually shifted to animal welfare-friendly housing systems for egg layers. However, there is still no consensus among researchers on whether the housing system affects egg quality traits. Therefore, this study aimed to determine the effects of housing systems on egg traits and free amino acid contents of albumen and yolk using two types of housing systems, the conventional cage (cage) system and a floor rearing (litter) system. Tosa-jidori (n = 20) hens were divided into two groups. Experiments during the 7 weeks were performed twice by switching the housing systems (first and second stages). One-way analysis of variance was used to evaluate the effects of housing systems on body weight gain, egg traits, albumen and yolk amino acid contents, and fecal corticosterone. We observed significant housing effects in body weight gain, eggshell weight, yolk weight, eggshell thickness, eggshell lightness, and several albumen amino acids (A_Gln, A_His, A_Met, A_Cys, A_Lys, A_Asp, A_Glu, A_Ser, A_Thr, A_Ala, A_Pro, and A_Phe). Notably, a robust effect was seen in eggshell lightness, even after switching housing systems. These results suggest that eggshell lightness and several egg traits, including albumen amino acid contents, can be changed by using the different housing systems.

Establishment of Wild-Derived Strains of Japanese Quail (Coturnix japonica) in Field and Laboratory Experiments.

Domestic quail are used as both farm and laboratory animals. As the wild ancestor of quails is "endangered," field studies are needed to conserve them. If wild-derived strains of quail are established, they will be unique genetic resources for both farm and laboratory animals. The purpose of the present study was to conduct a field study and create wild-derived quail strains using the breeding stocks in Tokachi, Hokkaido, Japan. Field observations from 2019 to 2022 indicate that wild quails migrate and stay at reproductive sites from late April to late October. Our estimations of the approximate ages of the observed and captured quails imply that adult males have intermittent reproductive opportunities from May to August. Morphological traits collected from adult and juvenile quails in the 2019-2022 population were similar to those previously reported for Japan's 1914 and 1970 populations. Using natural mating of captured wild males and domestic (Dom) females, we established the W50 and W75 strains, which possessed 50% and 75% genetic contributions from the wild stocks. These unique genetic resources can be applied for future conservation and experimental use to understand the domestication history and genetic basis of quantitative traits.

Combined Effect of Feed and Housing System Affects Free Amino Acid Content of Egg Yolk and Albumen in Brown Layer Chickens.

In recent years, the market share for cage-free eggs has gradually increased. Because commercially available cage-free eggs are often produced not only by several housing systems but also with different feed crude protein (CP) levels, there are combined effects of feed and housing systems between cage-free and cage eggs. Therefore, using field data, this study aimed to determine the combined effects of feed and housing systems on egg traits and yolk and albumen amino acids in table eggs. Brown layers (n = 40) at the middle laying stage under two feed and housing systems (cage, CP 15.5% diet; barn, CP 17.0% diet) were used. One-way analysis of variance and Pearson's correlation analysis were used to evaluate 10 egg traits, 19 yolk amino acid traits, and 20 albumen amino acid traits. We observed significant effects of feed and housing on two egg traits (yolk weight and eggshell color redness), 16 yolk amino acids (Asp, Glu, Asn, Ser, Gln, His, Arg, Thr, Ala, Tyr, Met, Cys, Ile, Leu, Phe, and Lys), and 14 albumen amino acids (Asp, Asn, Ser, Gln, Gly, His, Arg, Thr, Ala, Val, Met, Cys, Ile, and Leu). This study revealed that eggs from the barn system (CP 17.0%) contained higher levels of free amino acids in 15 yolk and nine albumen amino acid traits. Phenotypic correlations among the 49 egg traits indicated similar correlation patterns in both systems, which implies that the balance of free amino acid content in yolk and albumen is similar in each system. Although some potential confounding factors may be present for comparing egg content between cage (CP 15.5%) and barn (CP 17.0%) systems, this study suggests that commercially available cage-free eggs may be different from cage eggs not only in external egg traits but also yolk and albumen amino acid traits.

Morphological variations of caudal skeleton between three chicken breeds.

Although fancy caudae are important traits for chicken breeds, factors associated with their morphological diversity are not fully understood. We analyzed the caudal skeleton of the Tosa-jidori, Chabo, and Minohikichabo breeds with wild-type, erect, and rich caudae, respectively. Five of six Tosa-jidori chickens had four caudal vertebrae, whereas all six Chabo and five of six Minohikichabo chickens had five. The angle of the apex pygostyli with respect to the margo cranialis was significantly larger and smaller in Chabo and Minohikichabo than Tosa-jidori chickens, respectively. These findings indicated that the caudal skeleton is one of important factors for forming the characteristic traits of chicken breeds.

Polyoxocationic antimony oxide cluster with acidic protons.

The success and continued expansion of research on metal-oxo clusters owe largely to their structural richness and wide range of functions. However, while most of them known to date are negatively charged polyoxometalates, there is only a handful of cationic ones, much less functional ones. Here, we show an all-inorganic hydroxyiodide [H10.7Sb32.1O44][H2.1Sb2.1I8O6][Sb0.76I6]2·25H2O (HSbOI), forming a face-centered cubic structure with cationic Sb32O44 clusters and two types of anionic clusters in its interstitial spaces. Although it is submicrometer in size, electron diffraction tomography of HSbOI allowed the construction of the initial structural model, followed by powder Rietveld refinement to reach the final structure. The cationic cluster is characterized by the presence of acidic protons on its surface due to substantial Sb3+ deficiencies, which enables HSbOI to serve as an excellent solid acid catalyst. These results open up a frontier for the exploration and functionalization of cationic metal-oxo clusters containing heavy main group elements.

Phenotypic Analysis of Growth and Morphological Traits in Miniature Breeds of Japanese Indigenous Chickens.

Japanese indigenous chickens include approximately 50 breeds exhibiting various morphological traits, such as a long tail. These genetic resources will be important for revealing the genetic basis of morphological traits in the future. However, little is known about the phenotypic characteristics of each breed during the growth stages. To understand age-dependent changes in growth and morphological traits, we investigated tail length, tail number, body weight, and shank length at several time points using three genetically distinct Japanese indigenous chicken breeds. A total of 155 birds from the Tosa-jidori, Chabo, and Minohikichabo breeds were used for trait measurements from 1 to 36 weeks of age to reveal breed and sex effects. Significant sex differences through the growth stages were observed for all traits except for tail number. Although there were no clear breed differences in tail length traits at the 6- and 20-week stages, Minohikichabo ultimately had a significantly longer tail due to extended tail feather growth at later stages (28 and 36 weeks). By measuring two tail length variables (central and maximum), it was revealed that the shape of the tail feathers varies with the growth stage. Minohikichabo's tail number was higher than that of Tosajidori and Chabo at earlier ages (8 and 16 weeks), which leads to an elegant visual in Minohikichabo. Tosa-jidori's body weight was higher than that of Chabo and Minohikichabo, whereas the shank lengths of Chabo and Minohikichabo were shorter than those of Tosa-jidori. These differences in body weight and shank length were consistent from the early to late growth stages. These results revealed the age-dependency of growth and morphological trait breed characteristics.

Genotype affects free amino acids of egg yolk and albumen in Japanese indigenous breeds and commercial Brown layer chickens.

Using a variety of genetic resources, the aim of this study is to see how genetic background affects egg traits in chickens. Three different chicken genotypes (a commercial Brown layer, BOR; 2 Japanese indigenous breeds, NGY and YKD) were investigated effects on genotype in 10 external and internal egg quality traits along with 20 yolk and albumen free amino acid traits. Significant effects on genotype in 10 external and internal egg quality traits and 18 yolk and 17 albumen amino acid traits were found (P < 0.05). In sizes and weights of egg and eggshell redness, there were significant differences among all combinations of genotype (BOR > NGY > YKD). In 14 yolk (Asn, Ser, Gln, Gly, His, Arg, Ala, Pro, Tyr, Val, Met, Leu, Phe, and Lys) and 8 albumen amino acid traits (Gln, Gly, His, Arg, Val, Ile, Leu, and Lys), BOR was significantly higher than NGY and YKD, while the opposite relations were seen in 2 amino acid traits (Cys and GABA). Moreover, phenotypic correlation analyses revealed that positive correlations among amino acid traits within each yolk and albumen were broadly seen (0.30 < r < 0.98, P < 0.05). However, there are almost no phenotypic correlations in amino acids between yolk and albumen in BOR and NGY, but negative correlations in YKD, which implying a potential use of untapped genetic resources for modifying amino acid balance. These results indicate genetic background affects not only sizes and weights of egg but also amino acid contents and their balance of yolk and albumen.

Genetic effect on free amino acid contents of egg yolk and albumen using five different chicken genotypes under floor rearing system.

Chicken eggs play an important role as food resources in the world. Although genetic effects on yolk and albumen contents have been reported, the number of chicken genotypes analyzed so far is still limited. To investigate the effect of genetic background on 10 egg traits, 19 yolk amino acid traits, and 19 albumen amino acid traits, we evaluated a total of 58 eggs from five genotypes: two Japanese indigenous breeds (Ukokkei and Nagoya) and three hybrids (Araucana cross, Kurohisui, and Boris Brown) under a floor rearing system. One-way ANOVA revealed significant effects of genotype on 10 egg traits, 8 yolk amino acids (Asp, Glu, Ser, Gly, Thr, Tyr, Cys, and Leu), and 11 albumen amino acids (Asp, Glu, Asn, Ser, Gln, His, Ala, Tyr, Trp, Phe, and Ile) contents. Moderate to strong positive phenotypic correlations among traits within each trait category (size and weight traits, yolk amino acid traits, and albumen amino acid traits), whereas there were basically no or weak correlations among the trait categories. However, a unique feature was found in the Araucana cross indicating moderate positive correlations of amino acids between yolk and albumen. These results suggest that genetic factors can modify not only the size and weight of the egg and eggshell color but also yolk and albumen free amino acids contents.

Quantitative trait loci for growth-related traits in Japanese quail (Coturnix japonica) using restriction-site associated DNA sequencing.

This study aimed to identify quantitative trait loci (QTLs) for growth-related traits by constructing a genetic linkage map based on single nucleotide polymorphism (SNP) markers in Japanese quail. A QTL mapping population of 277 F2 birds was obtained from an intercross between a male of a large-sized strain and three females of a normal-sized strain. Body weight (BW) was measured weekly from hatching to 16 weeks of age. Non-linear regression growth models of Weibull, Logistic, Gompertz, Richards, and Brody were analyzed, and growth curve parameters of Richards was selected as the best model to describe the quail growth curve of the F2 birds. Restriction-site associated DNA sequencing developed 125 SNP markers that were informative between their parental strains. The SNP markers were distributed on 16 linkage groups that spanned 795.9 centiMorgan (cM) with an average marker interval of 7.3 cM. QTL analysis of phenotypic traits revealed four main-effect QTLs. Detected QTLs were located on chromosomes 1 and 3 and were associated with BW from 4 to 16 weeks of age and asymptotic weight of Richards model at genome-wide significant at 1% or 5% level. No QTL was detected for BW from 0 to 3 weeks of age. This is the first report identified QTLs for asymptotic weight of the Richards parameter in Japanese quail. These results highlight that the combination of QTL studies and the RAD-seq method will aid future breeding programs identify genes underlying the QTL and the application of marker-assisted selection in the poultry industry, particularly the Japanese quail.

Mapping of Quantitative Trait Loci Controlling Egg-Quality and -Production Traits in Japanese Quail (Coturnix japonica) Using Restriction-Site Associated DNA Sequencing.

This research was conducted to identify quantitative trait loci (QTL) associated with egg-related traits by constructing a genetic linkage map based on single nucleotide polymorphism (SNP) markers using restriction-site associated DNA sequencing (RAD-seq) in Japanese quail. A total of 138 F2 females were produced by full-sib mating of F1 birds derived from an intercross between a male of the large-sized strain with three females of the normal-sized strain. Eggs were investigated at two different stages: the beginning stage of egg-laying and at 12 weeks of age (second stage). Five eggs were analyzed for egg weight, lengths of the long and short axes, egg shell strength and weight, yolk weight and diameter, albumen weight, egg equator thickness, and yolk color (L*, a*, and b* values) at each stage. Moreover, the age at first egg, the cumulative number of eggs laid, and egg production rate were recorded. RAD-seq developed 118 SNP markers and mapped them to 13 linkage groups using the Map Manager QTX b20 software. Markers were spanned on 776.1 cM with an average spacing of 7.4 cM. Nine QTL were identified on chromosomes 2, 4, 6, 10, 12, and Z using the simple interval mapping method in the R/qtl package. The QTL detected affected 10 egg traits of egg weight, lengths of the long and short axes of egg, egg shell strength, yolk diameter and weight, albumen weight, and egg shell weight at the beginning stage, yellowness of the yolk color at the second stage, and age at first egg. This is the first report to perform a quail QTL analysis of egg-related traits using RAD-seq. These results highlight the effectiveness of RAD-seq associated with targeted QTL and the application of marker-assisted selection in the poultry industry, particularly in the Japanese quail.

1,6-hexanediol rapidly immobilizes and condenses chromatin in living human cells.

Liquid droplets formed inside the cell by liquid-liquid phase separation maintain membrane-less condensates/bodies (or compartments). These droplets are important for concentrating certain molecules and facilitating spatiotemporal regulation of cellular functions. 1,6-hexanediol (1,6-HD), an aliphatic alcohol, inhibits weak hydrophobic protein-protein/protein-RNA interactions required for the droplet formation (droplet melting activity) and is used here to elucidate the formation process of cytoplasmic/nuclear condensates/bodies. However, the effect of 1,6-HD on chromatin in living cells remains unclear. We found that 1,6-HD drastically suppresses chromatin motion and hyper-condenses chromatin in human cells by using live-cell single-nucleosome imaging, which detects changes in the state of chromatin. These effects were enhanced in a dose-dependent manner. Chromatin was "frozen" by 5%, or higher, concentrations of 1,6-HD. 1,6-HD greatly facilitated cation-dependent chromatin condensation in vitro. This 1,6-HD action is distinct from its melting activity of liquid droplets. Alcohols, such as 1,6-HD, appear to remove water molecules around chromatin and locally condense chromatin. Therefore, liquid droplet results obtained using 1,6-HD should be carefully interpreted or reconsidered when these droplets are associated with chromatin.

Impact on genetic differences among various chicken breeds on free amino acid contents of egg yolk and albumen.

Eggs play important roles as food resources and nutraceuticals, to alleviate malnutrition and to improve health status in the world. Since free amino acids contribute to the nutritional values and food tastes, we investigated a total of 81 eggs from five chicken breeds, which are Australorp, Nagoya (NGY), Rhode Island Red (RIR), Shamo (SHA), Ukokkei, and two F1 hybrids (NGYxRIR and SHAxRIR) to test impact on genetic differences in 10 egg traits, 20 yolk amino acid traits, and 18 albumen amino acid traits. One-way ANOVA revealed significant breed effects on 10 egg traits, 20 yolk amino acid traits, and 15 albumen amino acid traits. Moreover, a significant heterosis effect on yolk aspartic acid was identified. In addition, positive correlations were found broadly among traits within each trait category (egg traits, yolk amino acid traits, and albumen amino acid traits), whereas there were basically no or weak correlations among the trait categories. These results suggest that almost all traits can be dramatically modified by genetic factor, and there will be partially independent production systems of amino acids into yolk and albumen. Since there will be typical quantitative genetic architecture of egg contents, further genetic analyses will be needed.

Analyses of free amino acid and taste sensor traits in egg albumen and yolk revealed potential of value-added eggs in chickens.

To create high-quality eggs by using different breed and feed materials, we investigated free amino acid contents and taste sensor traits using two chicken breeds (Rhode Island Red; RIR and Australorp; AUS) fed two feeds (mixed and fermented feeds). Two-way ANOVA revealed significant breed and feed main and interaction effects on albumen bitterness and a significant interaction effect on yolk bitterness. Albumen from RIR fed mixed feed and AUS fed fermented feed was higher bitterness, whereas yolk from those groups was lower bitterness. Significant breed effects were detected in four albumen amino acid traits (His, Met, Ile, and Lys) and a yolk His, whereas significant feed effects were found in 15 albumen amino acid traits (Asp, Glu, Ser, His, Gly, Thr, Ala, Tyr, Val, Met, Trp, Ile, Leu, Lys, and Pro) and a yolk cystine trait. Compared to albumen amino acids, yolk amino acids had limited effects by breed and feed. The present results suggest that genetic and nutritional factors can alter not only amino acid contents but also sensor values of bitterness, indicating that selecting the combination of breed and feed enable us to make amino acids enriched and taste added designer eggs in future.

Combined change of behavioral traits for domestication and gene-networks in mice selectively bred for active tameness.

Tameness is a major element of animal domestication and involves two components: motivation to approach humans (active tameness) and reluctance to avoid humans (passive tameness). To understand the behavioral and genetic mechanisms of active tameness in mice, we had previously conducted selective breeding for long durations of contact and heading toward human hands in an active tameness test using a wild-derived heterogeneous stock. Although the study showed a significant increase in contacting and heading with the 12th generation of breeding, the effect on other behavioral indices related to tameness and change of gene expression levels underlying selective breeding was unclear. Here, we analyzed nine tameness-related traits at a later stage of selective breeding and analyzed how gene expression levels were changed by the selective breeding. We found that five traits, including contacting and heading, showed behavioral change in the selective groups comparing to the control through the generations. Furthermore, we conducted cluster analyses to evaluate the relationships among the nine traits and found that contacting and heading combined in an independent cluster in the selected groups, but not in the control groups. RNA-Seq of hippocampal tissue revealed differential expression of 136 genes between the selection and control groups, while the pathway analysis identified the networks associated with these genes. These results suggest that active tameness was hidden in the control groups but became apparent in the selected populations by selective breeding, potentially driven by changes in gene expression networks.

Breed and feed affect amino acid contents of egg yolk and eggshell color in chickens.

Genetic and environmental factors regulate hen egg traits. To demonstrate the possibility of producing designer eggs through genetic and environmental factors, we investigated the effects of breed and feed on egg traits using 2 chicken breeds, Rhode Island Red (RIR) and Australorp (AUS), and 2 feeds, mixed feed and fermented feed. A total of 40 eggs were collected at 33 wk of age (0 mo under mixed feed) and 1, 1.5, and 2 mo after switching to fermented feed. Two-way ANOVA mixed design was used to evaluate 10 egg traits: weight, length of the long axis, length of the short axis, eggshell weight, yolk weight, albumen weight, eggshell thickness, eggshell lightness, redness, and yellowness, and 19 yolk amino acids. The results revealed significant breed effects on eggshell redness and yellowness, with higher values of these traits in RIR eggs compared with AUS eggs. There was a significant effect of feed on eggshell lightness, with a lighter color observed under fermented feed compared with mixed feed. Significant effects of breed and breed × feed were found for yolk cysteine content. Eggs from AUS had a higher yolk cysteine content than those from RIR. The cysteine content in AUS eggs increased gradually after starting fermented feed, although RIR remained relatively constant over time. These findings suggest that it is possible to produce designer eggs with enriched components, including yolk amino acids, by adjusting both genetic and environmental factors. This represents a first step in understanding the mechanisms underlying the production of value-added eggs in chickens.

Metabolomic analyses of plasma and liver of mice fed with immature Citrus tumida peel.

In this study, we investigated the effects of dietary supplementation of Citrus tumida hort. ex Tanaka on food intake, body and fat tissue weights, and metabolic profiles of plasma and liver in mice. Supplementation with 5% (w/w) of peels of immature C. tumida (PIC) for 4 weeks significantly suppressed body weight gain and decreased adipose tissue weight in epididymal, perirenal, and subcutaneous fats. Metabolome analyses showed that 2-hydroxyvaleric acid levels were reduced in the blood plasma of mice fed with PIC. PIC supplementation significantly elevated dipeptide (Thr-Asp, Ser-Glu, and Ala-Ala), glucuronic acid, and S-methylglutathione levels, and significantly reduced betaine aldehyde levels in the liver. In conclusion, PIC supplementation affects the metabolism of fatty acids, pectin, glutathione, and choline, showing potential beneficial effects for metabolic syndrome and obesity. PIC may be developed as a functional food and used in the treatment of these diseases.

Metabolomics Approach Reveals the Effects of Breed and Feed on the Composition of Chicken Eggs.

Chicken eggs provide essential nutrients to consumers around the world. Although both genetic and environmental factors influence the quality of eggs, it is unclear how these factors affect the egg traits including egg metabolites. In this study, we investigated breed and feed effects on 10 egg traits, using two breeds (Rhode Island Red and Australorp) and two feed conditions (mixed feed and fermented feed). We also used gas chromatography-mass spectrometry (GC-MS/MS) to analyze 138 yolk and 132 albumen metabolites. Significant breed effects were found on yolk weight, eggshell weight, eggshell colors, and one albumen metabolite (ribitol). Three yolk metabolites (erythritol, threitol, and urea) and 12 albumen metabolites (erythritol, threitol, ribitol, linoleic acid, isoleucine, dihydrouracil, 4-hydroxyphenyllactic acid, alanine, glycine, N-butyrylglycine, pyruvic acid, and valine) were significantly altered by feed, and a significant interaction between breed and feed was discovered in one albumen metabolite (N-butyrylglycine). Yolk and albumin had higher levels of sugar alcohols when hens were fed a fermented diet, which indicates that sugar alcohol content can be transferred from diet into eggs. Linoleic acid was also enriched in albumen under fermented feed conditions. This study shows that yolk and albumen metabolites will be affected by breed and feed, which is the first step towards manipulating genetic and environmental factors to create "designer eggs."