Brown-shelled Eggs Research Articles

Mapping of QTL affecting incidence of blood and meat inclusions in egg layers

BackgroundOccurrence of blood and meat inclusions is an internal egg quality defect. Mass candling reveals most of the spots, but because brown eggshell hampers selection in brown chicken lines it has not been possible to eliminate the defect by selection. Estimated frequency of blood and meat inclusions in brown layers is about 18% whereas it is 0.5% in white egg layers. Several factors are known to increase the incidence of this fault: genetic background, low level of vitamin A and/or D, stress or infections, for instance. To study the genetic background of the defect, a mapping population of 1599 F2 hens from a cross of White Rock and Rhode Island Red lines was set up.ResultsOur histopathological analyses show that blood spots consist of mainly erythrocytes and that meat spots are accumulations of necrotic material. Linkage analysis of 27 chromosomes with 162 microsatellite markers revealed one significant quantitative trait locus (QTL) affecting blood spot and meat spot frequency. We sequenced a fragment of a candidate gene within the region, ZO-2, coding for a tight junction protein. Nine polymorphisms were detected and two of them were included in fine-mapping and association analysis. Fine-mapping defined the QTL result. To further verify the QTL, association analyses were carried out in two independent commercial breeding lines with the marker MCW241 and surrounding SNPs. Association was found mainly in a 0.8 Mb-wide chromosomal area on GGAZ.ConclusionsThere was good agreement between the location of the QTL region on chromosome Z and the association results in the commercial breeds analyzed. Variations found in tight junction protein ZO-2 and microRNA gga-mir-1556 may predispose egg layers to blood and meat spot defects. This paper describes the first results of detailed QTL analyses of the blood and meat spots trait(s) in chickens.

Observations on Main Quality Indices of Consumption Eggs Collected from Lohmann Brown Hen Hybrid

The research was conducted on eggs taken from Lohmann Brown hybrid, a hybrid created from pure lines (four lines) of Rhode-Island, which produce brown-shelled eggs. 60 eggs for consumption were analyzed, harvested at different ages (36 respectively 50 weeks). The recorded data were statistically processed and compared, from the Student test.

Are brighter eggs better? Egg color and parental investment by House Wrens

ABSTRACT Recent work suggests that avian egg color could be a sexually selected signal to males that provides information about female condition, female genetic quality, or maternal investment in eggs. Theory predicts that egg color should influence male investment if it is an honest signal of the marginal fitness returns on paternal investment; a male should invest more in a colorful clutch if that investment increases offspring success more than an equivalent investment in a less colorful clutch. Some experimental support for this hypothesis has been found for species that lay blue eggs containing the pigment biliverdin, a potentially costly antioxidant. However, the brown eggshell pigment protoporphyrin, a pro-oxidant associated with poor female condition, has received less attention as a potential predictor of female quality or investment. We performed a cross-fostering experiment with House Wrens (Troglodytes aedon) in southwest Michigan in 2007 to test whether brown egg color was related to female condition or maternal investment, and whether male provisioning of nestlings was related to egg color. We swapped entire clutches between nests and measured egg characteristics and parental provisioning rates. We found that brighter eggs (i.e., those with less brown pigment) were heavier, and that nestlings that hatched from brighter eggs were fed at higher rates by their foster mothers, but not by their foster fathers. This pattern is consistent with the hypothesis that egg color is a potential signal of egg quality and female investment, but we found no evidence of a male response to this potential signal. This lack of a response could be the result of methodological limitations, a nonadaptive biological constraint, or adaptive indifference because chicks from brighter eggs do not actually yield increasing marginal returns on paternal investment. Clearly, additional study is needed to differentiate among these possibilities. Un trabajo reciente sugiere que el color de los huevos pudiera ser una señal sexual que provee a los machos información sobre la condición de la hembra, la calidad genética de ésta o la inversión maternal en los huevos. La teoría predice que el color de los huevos debe influenciar en la inversión del macho si es una señal honesta de ganancia marginal de aptitud en la inversión parental; un macho debiera invertir más en una camada colorida si esta inversión aumenta el éxito de los hijos que una inversión equivalente en una camada menos colorida. La evidencia experimental, para esta hipótesis, ha sido encontrada para especies que ponen huevos azules los cuales contienen el pigmento biliverdina, que es un antioxidante potencialmente costoso. Sin embargo, el pigmento pardo en el cascarón, protoporfirina, un pro-oxidante asociado a una condición pobre de la hembra, ha recibido menos atención, como vaticinador potencial de la calidad de la hembra o de su inversión. En el 2007, realizamos un experimento de adopción cruzada en Reyezuelos (Troglodytes aedon) en el sureste de Michigan para poner a pruebas si los huevos pardos estaban relacionados a la condición de la hembra o a la inversión maternal, o si la atención (alimentación) de los machos a los pichones estaba relacionada al color de los huevos. Intercambiamos camadas entre nidos y medimos las características de los huevos y la taza de cuidado parental. Encontramos que los huevos más brillantes (ej. aquellos con menos pigmento pardo) eran más pesados, y que los pichones que nacían de estos huevos, eran más alimentados por sus madres nodrizas pero no así por sus padres adoptivos. Este patrón es consistente con la hipótesis de que el color de los huevos es una señal prospectiva o potencial de la calidad de los huevos e inversión maternal. Sin embargo, no encontramos evidencia, de esta señal potencial, en la respuesta de parte de los machos. Esta falta de respuesta pudiera ser el resultado de una limitación en la metodología utilizada, una limitación biológica no-adaptativa, o una indiferencia adaptativa, porque los pichones de huevos más brillantes no ofrecen un aumento de rendimiento marginal en la inversión parental. Claramente, se necesitan estudios adicionales para diferenciar entre estas posibilidades.

Physical quality and composition of retail shell eggs

There are a number of specialty shell eggs available to consumers in the US retail market. A survey consisting of white and brown large shell eggs with various production and nutritional differences (traditional, cage-free, free-roaming, pasteurized, nutritionally enhanced, and fertile) was conducted to determine if physical quality and compositional differences exist. Identical brands of eggs were purchased from the same retail outlets on 3 occasions (replicates) in a single city. The average range of time from processing to purchase for all eggs was 7.67 to 25.33 d, with traditional white eggs in retail having the shortest time. Haugh unit values ranged from 66.67 (cage-free, docosahexaenoic acid, and n-3 enhanced) to 84.42 (traditional white). Albumen height followed a similar pattern. Egg weight was greater for brown eggs (61.12 vs. 58.85 g). Brown eggs also had greater static compression shell strength than white eggs (4,130.61 vs. 3,690.31 g force). Vitelline membrane strength was greatest for traditional brown eggs (2.24 g force). Percentage of total solids and crude fat was greatest in the cage-free, n-3-enhanced white eggs (25.07 and 11.71%, respectively). Although significant differences were found between white and brown shell eggs and production methods, average values for quality attributes varied without one egg type consistently maintaining the highest or lowest values.

Impact of Layer Breeder Flock Age and Strain on Mechanical and Ultrastructural Properties of Eggshell in Chicken

This investigation was carried out to study mechanical eggshell traits (weight, specific gravity, eggshell thickness and eggshell breaking strength) and ultrastructural properties from layer breeder hens at different ages (25, 47 and 61 weeks). The present results showed that the brown eggshell had significantly higher specific gravity, shell thickness and breaking strength compared to white eggshell. Concerning breeder flock age, it could be noticed that the age of hen significantly affected mechanical eggshell traits, where specific gravity, shell thickness and breaking strength decreased significantly as the breeder age was advance. With respect to eggshell ultrastructural properties, the brown eggshell had significantly higher effective thickness (palisade %) compared to white ones. Opposite trend was observed for relative cap thickness. With regard to layer breeder flock age effect, the results indicated that the effective thickness (palisade %) was significantly decreased as the layer breeder flock age increased. Conversely, the relative cap thickness was increased with age increased. With respect to confluence trait, the present results observed that both brown and white eggs owned shells with similar values of confluence. Significant difference observed between strains regarding fusion (early or late) trait. Type B's, type A's and alignment traits in eggshell produced from older breeders was significantly higher that of younger breeders.

Comparison of the total amount of eggshell pigments in Dongxiang brown-shelled eggs and Dongxiang blue-shelled eggs

Based on the knowledge of the heme bio-synthetic and metabolic pathway and the structures of biliverdin and protoporphyrin, experiments were carried out to compare the difference between the total quality of eggshell pigments in blue-shelled eggs and brown-shelled eggs from the same population (Dongxiang, China) and to analyze the correlation between the quantity of protoporphyrin and biliverdin in the 2 kinds of eggshells. It was found that there was no significant difference between the total quantity of eggshell pigments in Dongxiang blue-shelled eggs and Dongxiang brown-shelled eggs (P = 0.9006), and a highly significant positive correlation between the quantity of protoporphyrin and biliverdin in blue eggshells (P < 0.01) and a significant positive correlation between the quantity of protoporphyrin and biliverdin in brown eggshells (P < 0.05). These results suggested that eggshell protoporphyrin and eggshell biliverdin probably derived from common precursor material.

Vital Tooth Bleaching : A Study on the Irradiation Time by Means of Brown Eggshell

Vital Tooth Bleaching : A Study on the Irradiation Time by Means of Brown Eggshell

Study of the Deposition Process of Eggshell Pigments Using an Improved Dissolution Method

An improved dissolution method called layer-by-layer dissolution was adopted to study the process of eggshell deposition, which is opposite to the process of eggshell dissolution. In the present study, blue and brown eggshells from 2 Chinese indigenous chicken breeds, Dongxing and Shouguang, respectively, were analyzed with layer-by-layer dissolution. The results showed that the deposition velocity of the eggshell pigments in the top (first) eggshell layer was the highest compared with other layers, which were biliverdin and protoporphyrin in blue eggshell or primarily protoporphyrin in brown eggshell. It was also revealed that the deposition processes of biliverdin and protoporphyrin were synchronous in the blue eggshell of the Dongxiang chicken in the present study.

Comparative Pigmentation Efficiency of High Dietary Levels of Apo-Ester and Marigold Extract on Quality Traits of Whole Liquid Egg of Two Strains of Laying Hens

This trial was carried out to compare the effect of the dietary supplementation of high doses of either synthetic pigment ethyl ester of β-apo-8′-carotenoic acid (apo-ester) or natural pigments, mainly lutein and zeaxanthin, extracted from Tagetes erecta, on egg quality of hens laying brown shell eggs (ISA Brown) and white shell eggs (Hy-Line White W-36). The hens of each strain were divided into 6 groups and fed a corn-soybean basal diet supplemented either with 40, 60, and 80 ppm of apo-ester (APO) or with 120, 180, and 240 ppm of marigold extract (MAR). Egg pigmentation rose linearly and significantly (P < 0.01) as the dietary levels of apo-ester increased, but this did not occur when MAR supplementation was used. The amount of β-carotene equivalents in whole liquid egg of MAR treatments was almost constant with varying pigment dietary dose and was significantly lower (P < 0.01) than in APO treatments. In both hen strains, whole liquid egg redness (a*) and yellowness (b*) were higher with APO supplementation. The egg component weights were highly affected (P < 0.01) by the hen strain, with yolk:egg ratio higher in the Hy-Line. The trial confirms that in spite of the higher level of MAR supplementation, APO has a better efficiency in whole liquid egg pigmentation. The ISA Brown hens showed a better ability to absorb dietary carotenoids than did the Hy-Line White.

Monitoring the Egg Freshness During Storage Under Modified Atmosphere by Fluorescence Spectroscopy

A total of 207 intact brown-shelled eggs of the same flock (29 weeks of age) belonging to two treatment groups were stored in daylight at 12.2 °C and 87% relative humidity (RH): (1) 108 eggs and (2) 99 other eggs were kept in an atmosphere containing 2 and 4.6% of CO2, respectively. The 18 remaining eggs have also been analysed directly when they were available in our laboratory to check the degree of freshness (aged of 1 day or less). Eggs of the two groups were analysed after 6, 8, 12, 15, 20, 22, 26, 29, 33, 40, 47 and 55 days of storage using front face fluorescence spectroscopy. The emission fluorescence spectra of aromatic amino acids and nucleic acids (AAA+NA; excitation, 250 nm; emission, 280–450 nm), fluorescent Maillard reaction products (excitation, 360 nm; emission, 380–580 nm) and the excitation spectra of vitamin A (emission, 410 nm; excitation, 270–350 nm) were scanned on thick albumen and egg yolk. For each treatment, the principal component analysis applied on the vitamin A fluorescence spectra allowed a good discrimination of eggs according to both their storage time and conditions, while more overlapping between egg samples was observed when the other intrinsic probes were investigated. These results showed that vitamin A fluorescence spectra could be considered as a good indicator of egg freshness kept only in 2% of CO2.

Changes in Brown Eggshell Color As the Hen Ages

The color of eggshells from eggs laid by commercial-type Hy-Line brown hens 25 wk of age was studied over a period of 10 mo. Color measurements were made by a color machine vision system and were analyzed using a mixed model to calculate between and within hen variances and to investigate the effect of time on shell color. Hens laid eggs with lighter colored shells as the flock aged, as evidenced by the lightness (L*) values increasing in time. A decrease in pigmentation was associated with a decrease in the amount of redness (a*) in the eggshell. When L* and a* values were corrected for egg weight, the rate of change in the L* and a* values decreased, indicating that size of the egg was a major factor affecting the color of the eggshell. These findings quantified the observations that older hens lay lighter colored eggs due to an increase in egg size associated with no proportionate change in the quantity of pigment deposited over the shell surface. Using a 2-stage sampling analysis and the variances between and within hens, sample sizes required to estimate the color of eggshells within 5% of the true mean were calculated. Accordingly, 11 eggs would need to be collected from each of the 51 hens housed for a study of brown eggshell color using the L*, a*, and b* (yellowness) coordinates.

Effect of Genotype on Slaughtering Performance and Meat Physical and Sensory Characteristics of Organic Laying Hens

Slaughtering yields and some meat physical and sensorial parameters of laying hens reared under organic system production were studied. The hens belonged to both Italian dual-purpose breeds [Ermellinata di Rovigo (ER; brown eggshell) and Robusta Maculata (RM; brown eggshell)] as well as hybrid genotypes [Hy Line White 36 (white eggshell) and Hy Line Brown (brown eggshell)]. The birds were reared under organic farming system production from 24 to 44 wk of age, when they were slaughtered. They were reared throughout summer and autumn, and the temperature ranged from about 28 to 3 degrees C. Local breeds presented higher (P < 0.01) live BW and dressing percentage compared with hybrids. The RM and ER carcasses had (P < 0.01) the highest breast and leg (thigh and drumstick) percentage, respectively. The muscle-bone ratio of the Hy Line White 36 drumstick was lower (P < 0.05) than the RM ratio, whereas the other groups were intermediate. The ER breast presented the highest (P < 0.01) lightness value and the lowest (P < 0.01) final pH value compared with the other 3 groups. The breast meat significantly differed according to genotype for almost all the studied sensorial parameters (adhesivity, fibrousness, chewiness, solubility, juiciness, tenderness, shear resistance), with the exception of aroma and odor intensity. In the thigh, genotype significantly affected aroma, adhesivity, fibrousness, solubility, tenderness, and shear resistance.

Bleaching of Vital Tooth : Application of Brown Eggshell as a Bleaching Standard

Bleaching of Vital Tooth : Application of Brown Eggshell as a Bleaching Standard

Vitamin C Overcomes the Detrimental Effect of Vanadium on Brown Eggshell Pigmentation

Phosphorus supplementation from poor quality feed-grade sources may introduce excessive levels of vanadium (V) into the diets of laying hens. Vanadium in the diet of chickens has been shown to be detrimental to egg production, albumen height, BW, and feed consumption. This study showed that dietary V also has a negative effect on the color of brown eggshells from commercial-type layers. Commercial-type brown egg layers were fed a cornsoybean meal basal diet supplemented with 0, 50, or 100 ppm of V as NH4 VO3 to determine the effect on shell pigmentation. Hens fed V at both dietary concentrations laid lighter colored eggs (less redness) after only 2 d. Another experimental group of the same type of hens that were fed lower V concentrations (0, 15, or 30 ppm) also had less shell pigmentation. After the detrimental “bleaching” effect on shell color was observed, these diets were supplemented with 1 of the following: no supplement, 100 ppm of vitamin C, 100 IU of vitamin E, or 100 ppm of β-carotene. Only vitamin C restored the eggshell color of eggs from hens fed both levels of V. When these same antioxidants were added as preventive agents to diets supplemented with 15 ppm of V before the effects of V were established, brown layers benefited again from 100 ppm of vitamin C but not from vitamin E or β-carotene.

Egg Embryo Development Detection with Hyperspectral Imaging

In the U. S. egg industry, anywhere from 130 million to over one billion infertile eggs are incubated each year. Some of these infertile eggs explode in the hatching cabinet and can potentially spread molds or bacteria to all the eggs in the cabinet. A method to detect the embryo development of incubated eggs was developed. Twelve brown-shell hatching eggs from two replicates (n=24) were incubated and imaged to identify embryo development. A hyperspectral imaging system was used to collect transmission images from 420 to 840 nm of brown-shell eggs positioned with the air cell vertical and normal to the camera lens. Raw transmission images from about 400 to 900 nm were collected for every egg on days 0, 1, 2, and 3 of incubation. A total of 96 images were collected and eggs were broken out on day 6 to determine fertility. After breakout, all eggs were found to be fertile. Therefore, this paper presents results for egg embryo development, not fertility. The original hyperspectral data and spectral means for each egg were both used to create embryo development models. With the hyperspectral data range reduced to about 500 to 700 nm, a minimum noise fraction transformation was used, along with a Mahalanobis Distance classification model, to predict development. Days 2 and 3 were all correctly classified (100%), while day 0 and day 1 were classified at 95.8% and 91.7%, respectively. Alternatively, the mean spectra from each egg were used to develop a partial least squares regression (PLSR) model. First, a PLSR model was developed with all eggs and all days. The data were multiplicative scatter corrected, spectrally smoothed, and the wavelength range was reduced to 539 - 770 nm. With a one-out cross validation, all eggs for all days were correctly classified (100%). Second, a PLSR model was developed with data from day 0 and day 3, and the model was validated with data from day 1 and 2. For day 1, 22 of 24 eggs were correctly classified (91.7%) and for day 2, all eggs were correctly classified (100%). Although the results are based on relatively small sample sizes, they are encouraging. However, larger sample sizes, from multiple flocks, will be needed to fully validate and verify these models. Additionally, future experiments must also include non-fertile eggs so the fertile / non-fertile effect can be determined.

Front face fluorescence spectroscopy as a tool for the assessment of egg freshness during storage at a temperature of 12.2 °C and 87% relative humidity

The objective of this study was to investigate intrinsic fluorophores of thick albumen and egg yolk in order to assess egg freshness during storage at a temperature of 12.2 °C and 87% relative humidity (RH). A total of 126 intact brown-shelled eggs of the same flock (29 weeks of age) were stored for 1, 6, 8, 12, 15, 20, 22, 26, 29, 33, 40, 47 and 55 days. The emission fluorescence spectra of aromatic amino acids and nucleic acids (AAA + NA) (excitation: 250 nm; emission: 280–450 nm), fluorescent Maillard reaction products (FMRP) (excitation: 360 nm; emission: 380–580 nm) and the excitation spectra of vitamin A (emission: 410 nm; excitation: 270–350 nm) were scanned on thick albumen and egg yolk. Among the intrinsic fluorophores, only the principal component analysis (PCA) applied on the vitamin A fluorescence spectra allowed a good identification of eggs as a function of their storage time. Factorial discriminant analysis (FDA) was then applied on the first five principal components (PCs) of the PCA applied on each spectral data set. Regarding AAA + NA recorded on thick albumen, correct classification of 69.4% and 63.9% was observed for the calibration and validation sets, respectively. Quite similar results were obtained on AAA + NA scanned on egg yolks. The best results were obtained with vitamin A fluorescence spectra since 97.7% and 85.7% of the calibration and validation sets was obtained, respectively. These results showed that vitamin A fluorescence spectra provide useful fingerprints, mainly allow the identification of eggs during storage and could be considered as a powerful intrinsic probe for the evaluation of egg freshness.

Acute Depigmentation of Fertile Brown Eggs in a Commercial Layer Operation

Rapid depigmentation of brown eggs is an infrequent but startling event in the commercial egg industry that can result in significant economic losses. Loss of shell pigment in brown-shelled eggs is caused by various factors. In many cases, the exact cause of flock-wide pigment loss remains undetermined. A rapid decline in shell pigmentation was observed in 2 flocks of Hyline brown layers. The lack of evidence of an infectious disease process suggested a feed or management problem. On the basis of a small-scale, "in-house" feeding trial, the feed was identified as the cause of depigmentation. Feed analysis by liquid chromatography with mass spectrometry confirmed the presence of 4,4'-dinitrocarbanilide, a major component of nicarbazin (NCZ). There was no evidence of increased mortality, and only a slight but transient drop in the egg production was observed. Depigmentation effects were rapidly reversed after replacing the feed with NCZ-free feed.

Effect of intensity of eggshell pigment and illuminated incubation on hatchability of brown eggs

1. The effects of intensity of brown eggshell pigment (light (LBP), medium (MBP) and dark (DBP)) and light intensity during incubation (low and high, 900 to 1380 and 1430 to 2080 lux, respectively) on eggshell characteristics, embryonic growth, hatchability traits, chick hatching weight and hatching time were investigated using eggs from a meat-type breeder (Hybro) flock at 32, 36 and 41 weeks of age in three trials. 2. With eggs of similar weights the intensity of brown pigment was not associated with eggshell weight and thickness, and did not influence embryo weight and egg weight loss during incubation. 3. The shade of brown pigment of eggs laid by young hens influenced the percentage hatchability (HP) of eggs incubated under light. Illuminated incubation improved HP of LBP eggs (compared with MBP and DBP eggs) from 32- and 36-week-old hens, but had no significant effect on HP of eggs from 41-week-old hens. 4. Light intensity during incubation did not influence egg weight loss. High intensity of light during incubation reduced HP and increased early death percentage (EDP) in the LBP and MBP groups, and did not influence HP and EDP in the DBP group. 5. Brown eggshell pigment and intensity of light during incubation did not influence hatching time. 6. It is concluded that the shade of brown pigment, intensity of light during incubation and age of the breeder hens influenced the hatchability performance of embryos from brown eggs. Light during incubation improved the hatchability of embryos in light brown eggs laid by young hens and the shade of brown pigment of eggs laid by older hens did not influence hatchability under illuminated incubation. 7. High intensity of light during incubation reduced hatchability of light and medium brown eggs, but not the dark brown eggs.

Substitution of soyabean meal with “00” rapeseed meal or its high-protein fraction in the nutrition of hens laying brown-shelled eggs

Substitution of soyabean meal with “00” rapeseed meal or its high-protein fraction in the nutrition of hens laying brown-shelled eggs

Re-evaluation of calcium and phosphorus requirements in aged laying hens

1. A series of 5 trials was conducted with 401- to 650-d-old Lohmann, Yafa (local breed with brown eggshells) and Yarkon (local breed with white eggshells) hens fed for 56 to 84 d with diets containing 25 to 50 g/kg calcium (Ca) and 4.5 to 7.6 g/kg phosphorus (P). 2. Increasing dietary Ca from 24-25 to 36-40 g/kg improved egg production, shell weight (SW) and shell thickness (ST), and decreased mortality. 3. Increasing dietary Ca to 48 to 50 g/kg did not affect egg production but increased SW and/or ST. In one out of the 4 trials, this effect was not significant, most likely because of the high shell quality of the eggs from the Yafa hens used for this trial. 4. Dietary P content of 4.5 g/kg (1.0 g/kg added inorganic P) appears to be sufficient for maintaining egg production and shell quality in aged laying hen given 36 to 40 g/kg Ca. 5. Increasing dietary Ca above 40 g/kg may require a higher dietary P content.