Eggshell Color Research Articles

Effects of dietary organic or inorganic iron concentrations on productive performance, egg quality, blood measurements, and tissue iron concentrations in aged laying hens.

The objective of the current experiment was to investigate the effects of dietary organic or inorganic iron (Fe) concentrations on productive performance, egg quality, blood measurements, and tissue Fe concentrations in aged laying hens. A total of three hundred fifty 60-week-old Hy-Line Brown laying hens were allotted to one of five dietary treatments with seven replicates. Each replicate had 10 consecutive cages. Organic Fe (Fe-Gly) or inorganic Fe (FeSO4 ) was added to the basal diet at the levels of 100 or 200 mg/kg Fe. Diets were fed on an ad libitum basis for 6 weeks. Results indicated that supplementation of organic or inorganic Fe in diets increased (p < 0.05) eggshell color and feather Fe concentrations compared with no supplementation of Fe in diets. An interaction was found (p < 0.05) between Fe sources and supplemental levels in diets for egg weight, eggshell strength, and Haugh unit. Hens fed diets supplemented with organic Fe had greater (p < 0.05) eggshell color and hematocrit than those fed diets supplemented with inorganic Fe. In conclusion, dietary supplementation of organic Fe increases the eggshell color of aged laying hens. High supplemental levels of organic Fe in diets improve egg weight in aged laying hens.

ФАКТОРЫ, ВЛИЯЮЩИЕ НА ПИГМЕНТАЦИЮ СКОРЛУПЫ КУРИНЫХ ЯИЦ (ОБЗОР)

The paper is devoted to studying of brown hen egg shell pigmentation mechanism and factors that influence the pigmentation. Protoporfirine-IX has been established to determine hen egg shell brown color especially this com- pound high fluorescent monomer (colored pigment). This pigment is synthesised in epithelial cells of oviduct uterus. Any factor that disturb these cells possibility to synthesise pigment or to ensure cuticle deposition will effect negatively on egg shell color intensity.

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.

Egg Quality of Italian Local Chicken Breeds: I. Yield Performance and Physical Characteristics.

The aim of this study was to compare yield performance (from 39 to 50 weeks of age) and egg physical characteristics (at 50 weeks of age) of eight autochthonous chicken breeds of the Veneto region (Italy). Four white eggshell breeds, namely Padovana Camosciata (PA-C, chamois plumage), Padovana Dorata (PA-G, golden plumage), Polverara Bianca (PO-W, white plumage), and Polverara Nera (PO-B, black plumage), and four tinted eggshell breeds, namely Pepoi (PP), Ermellinata di Rovigo (ER), Robusta Maculata (RM), and Robusta Lionata (RL) from a conservation centre were considered in the trial. Significant differences (p < 0.05) among breeds were observed for yield performance and egg quality. From 39 to 50 weeks of age, the hen-day egg production was higher in PA-C and RM than in RL, and PO-W and ER were intermediate; PA-G, PO-B, and PP were the lowest. The hen-day egg production changed according to the age of the hens. From 39 to 42 weeks of age, ER showed the highest hen-day egg production and PA-G the lowest; from 47 to 50 weeks, PA-C, PO-W, and RM were the highest and PP the lowest. The tinted eggshell breeds, with the exception of PP, had higher egg weights than white eggshell breeds. PP egg weight was similar to PO-B. As regards the tinted eggshell breeds, RM eggs had the highest eggshell a* and b*, and PP the lowest. PA-C had the most spherical eggs, and PO-B and ER had the most ovoid eggs. PO-W and RM had the highest eggshell thickness and ER had the lowest. The highest eggshell ratio was observed for PO-W and PO-B, and the lowest for ER. The yolk-to-albumen ratio was higher in the white eggshell breeds than in PP, ER, and RL. ER had the highest Haugh units and PA-G the lowest. PO-W, PO-B, PA-C, PA-G, and ER had the lowest egg inclusions, and RL and RM the highest. Tinted eggshell eggs differed from white eggshell eggs by having higher meat spots. Results indicated that the eggs produced by the eight local chicken breeds differed according to the laying rate and a wide range of physical external and internal characteristics which allow the consumer to distinguish them for their genetic origin by the eggshell shape and colour, and to use them for different purposes to valorise poultry biodiversity.

IMPACT OF EGG SHELL AND SPOTS COLOUR ON THE QUALITY OF HATCHING EGGS DERIVED FROM THREE LINES OF LOCAL QUAIL

This study was carried out to analyze the impact of lines, egg shell colour and intraction between (Line ⁎ eggshell colours) on egg quality characteristics and hatching parameters assess the correlation between these traits in three local quail eggs (desert, brown and white). A total of 409 eggs were collected from female quails during 16 weeks divided into five groups on the basis of eggshell colour and spot colour for each line. The results revealed that there were significant (P≤0.05) variances among lines for quality characteristics of the whole egg (weight, length, width, Egg volume, Haugh unit), albumen (weight, height, diameter), yolk (weight, height, index, Yolk/albumen) and shell (weight, thickness, egg surface area, unit surface). The desert line resulted in the best quality. The results demonstrated that internal and external egg quality characters were differed significantly among egg shell colour. Whereas, yolk parameters such as: yolk weight, yolk height, Yolk diameter and Yolk percentage revealed no significance differences among these groups. Phenotypic correlation appeared that there were significant correlation coefficients among the internal and external egg quality traits. The incubation characteristics, fertility, hatchability of fertile eggs, hatchability of set eggs and Chick hatching weight were significantly differences among eggshell colour groups within lines.

Quantitative and qualitative traits characterisation of indigenous chickens in Southern African countries

Indigenous poultry production is important to human lives as they alleviate poverty by providing an affordable source of animal proteins. Besides, it serves as the easiest source of income for rural farmers in developing countries. The current review was conducted to evaluate the research findings of indigenous chickens’ quantitative and qualitative traits characterisations in Southern African countries. Quantitative and qualitative traits characterisation is the first step for genetic improvement in livestock. The documents used in the review were attained from different search engines, most of which were published lately (after 2010). Potchefstroom Koekoek, Venda, Naked Neck, Ovambo, Boschveld and Tswana indigenous chicken breeds in the Southern African countries were characterised. The studies suggest that there are variations in quantitative traits including live weight, egg weight, wing length, comb length and shank length and qualitative traits including feather color, comb type, comb color and eggshell color of indigenous chickens of Southern African countries. The single red comb types and red wattles were observed in most indigenous chicken breeds in Southern African countries. The present review concludes that the characterisation of quantitative and qualitative traits assists greatly in the differentiation and identification of indigenous chicken breeds.

Ameliorative effects of dietary selenium against cadmium toxicity on production performance and egg quality in laying hens

In order to reveal the influences of supplemented dietary selenium (Se) on the suppressive effect of cadmium (Cd) toxicity on performance and egg properties of laying hens, the effects of co-treatment Se and Cd on the performance, egg quality, levels of amino acids and the antioxidant capacity of egg and serum were investigated. A total of 128 31-week-old laying hens were randomly distributed in four treatments, which were fed with the basic diet (0.2 mg/kg Se and 0.08 mg/kg Cd), and the basic diet with Se (1.1 mg/kg Se and 0.08 mg/kg Cd), Cd (0.2 mg/kg Se and 92.1 mg/kg Cd) and Se+Cd for 13 weeks, respectively. Hens supplemented with Cd led to an impairment on production performance and egg quality with decreased egg production (EP), egg mass (EM), feed intake (FI), eggshell color, eggshell thickness, yolk color, albumen height and haugh unit and increased the feed conversion ratio (FCR) (p < 0.05). Cd treatment decreased the contents of cysteine (Cys), histidine (His), lithium (Li), aluminum (Al), chromium (Cr), manganese (Mn), nickel (Ni), zinc (Zn), arsenic (As), Se, strontium (Sr), stannum (Sn), mercury (Hg) and thallium (Tl) and increased the contents of isoleucine (Ile) and Cd (p < 0.05). Cd destroyed the egg yolk and serum redox states with the increased concentration of malondialdehyde (MDA) and the decreased activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) (p < 0.05). The expression levels of ovarian apoptotic genes (protein 53, Caspase9, Cytochrome c and Bcl-2 associated X protein) increased, and B-cell lymphoma 2 (Bcl-2) expression decreased in the Cd group (p < 0.05). Feeding Se significantly alleviated Cd-induced toxicity on performance and egg quality. Se+Cd treatment restored the balance between oxidation and antioxidant systems and modulated the elements' homeostasis and alleviated the changes in apoptotic-related genes expression levels. Se could alleviate the Cd toxicity to laying hens and their eggs but could not counteract all negative effects of Cd.

Identification of crucial genes and metabolites regulating the eggshell brownness in chicken

BackgroundProtoporphyrin IX (Pp IX) is the primary pigment for brown eggshells. However, the regulatory mechanisms directing Pp IX synthesis, transport, and genetic regulation during eggshell calcification in chickens remain obscure. In this study, we investigated the mechanism of brown eggshell formation at different times following oviposition, using White Leghorn hens (WS group), Rhode Island Red light brown eggshell line hens (LBS group) and Rhode Island Red dark brown eggshell line hens (DBS group).ResultsAt 4, 16 and 22 h following oviposition, Pp IX concentrations in LBS and DBS groups were significantly higher in shell glands than in liver (P < 0.05). Pp IX concentrations in shell glands of LBS and DBS groups at 16 and 22 h following oviposition were significantly higher than WS group (P < 0.05). In comparative transcriptome analysis, δ-aminolevulinate synthase 1 (ALAS1), solute carrier family 25 member 38 (SLC25A38), ATP binding cassette subfamily G member 2 (ABCG2) and feline leukemia virus subgroup C cellular receptor 1 (FLVCR1), which were associated with Pp IX synthesis, were identified as differentially expressed genes (DEGs). RT-qPCR results showed that the expression level of ALAS1 in shell glands was significantly higher in DBS group than in WS group at 16 and 22 h following oviposition (P < 0.05). In addition, four single nucleotide polymorphisms (SNPs) in ALAS1 gene that were significantly associated with eggshell brownness were identified. By identifying the differential metabolites in LBS and DBS groups, we found 11-hydroxy-E4-neuroprostane in shell glands and 15-dehydro-prostaglandin E1(1-) and prostaglandin G2 2-glyceryl ester in uterine fluid were related to eggshell pigment secretion.ConclusionsIn this study, the regulatory mechanisms of eggshell brownness were studied comprehensively by different eggshell color and time following oviposition. Results show that Pp IX is synthesized de novo and stored in shell gland, and ALAS1 is a key gene regulating Pp IX synthesis in the shell gland. We found three transporters in Pp IX pathway and three metabolites in shell glands and uterine fluid that may influence eggshell browning.

Effect of folic acid supplementation to Lohmann Brown layers diet on performance, egg quality and folic acid content of eggs and serum

Sometimes, customers added folic acid to layer diet to enhance brown egg shell color. This supplementation may lead to increase the content of folic acid in serum and eggs. The increment of folic acid in egg lead to produce folate egg that it will be beneficial to customers health especially pregnant women. This study was carried out to investigate the effect of supplementation of folic acid enriched diet on layer performance, egg quality, and folic acid content of egg and serum. Five thousand Lohmann classic brown laying hen’s type were use in this experiment. At the first period, hens were fed on basal diet according to Lohmann Classic Brown nutrition requirement guide. The Second period of the experiment, all hens were fed same basal diet enriched with folic acid with 1mg/kg of feed. Eggs were collected and blood samples were collected from the layers at the end of the first and second periods for measuring folic acid content of egg and serum by using HPLC &amp; ELIZA respectively. Egg quality were measuring by calculating of egg weight, albumin height, albumin diameter, yolk height, yolk diameter, yolk color, shell thickness and Haugh unit.

Consider, “Egg characteristics of Tsushima-jidori chickens”

The Tsushima-jidori are a native breed of chickens in Tsushima City, Nagasaki Prefecture, and have long been kept as egg-laying hens in garden poultry farms. In order to improve the egg-laying ability of Tsushima-jidori, they were crossed with red eggshell laying hens, which have higher egg-laying ability, and the egg-laying characteristics of the crossed hens were investigated. The crossbred chickens were found to have higher egg-laying ability than the Tsushima-jidori, a more elongated egg shape compared to the red eggshell laying hens, and an eggshell color of pink to almost reddish-brown. The general egg composition showed inherited characteristics of both Tsushima-jidori and red eggshell hens. The large yolk ratio is a characteristic of Tsushima-jidori hens, and hens resulting from crossbreeding with Tsushima-jidori hens inherited the same characteristics. Further, eggshell thickness and strength, and Haugh unit were improved by crossbreeding with red eggshell hens. These results suggest that crossbred Tsushima-jidori hens can inherit characteristics of the original Tsushima-jidori hens while exhibiting high egg-laying ability and producing distinctive eggs.

A new molecular mechanism supports that blue-greenish egg color evolved independently across chicken breeds

Chicken blue-greenish coloration (BGC) was known as a classic Mendel trait caused by a retrovirus (EAV-HP) insertion in the SLCO1B3 gene. Lueyang black-boned chicken (LBC) BGC is light and varies continuously, implying that LBC BGC may be controlled by a new molecular mechanism. The aim of this study was to provide an insight into the molecular basis of LBC BGC. The EAV-HP was detected in the BGC (n = 105) and non-BGC LBC (n = 474) using a PCR-based method. The association of SLCO1B3 expression in shell glands and sequence variants in a 1.6-kb region upstream from the transcription start site of SLCO1B3 with eggshell color and biliverdin (pigment for BGC) concentration was studied. Promoter activities of haplotypes in the 1.6-kb region were analyzed by luciferase reporter assay. This study did not found the EAV-HP in BGC and Non-BGC LBC, but detected a strong positive correlation between levels of SLCO1B3 expression in shell glands and biliverdin concentrations. A total of 31 SNP were found in the 1.6-kb region. Twenty-two of 31 SNP formed 42 types of haplotypes in the re-sequenced samples (n = 94). Haplotype 4 was present in higher frequency in the BGC (52%) than Non-BGC (3%). Haplotype 13 was significantly associated with Non-BGC (Non-BGC vs. BGC = 26% vs. 6%). In line with the above associations, Haplotype 4 showed higher (P < 0.05) levels of SLCO1B3 expression in shell glands, biliverdin concentration, and promoter activity than Haplotype 13. This study confirms that LBC BGC is not caused by the EAV-HP, but remains to be associated with the change of SLCO1B3 expression. Haplotype 4 accounts to some extents for the molecular basis of LBC BGC. The new molecular mechanism supports LBC BGC independently evolved.

Quantitative analysis of CRISPR/Cas9-mediated provirus deletion in blue egg layer chicken PGCs by digital PCR

Primordial germ cells (PGCs), the precursors of sperm and oocytes, pass on the genetic material to the next generation. The previously established culture system of chicken PGCs holds many possibilities for functional genomics studies and the rapid introduction of desired traits. Here, we established a CRISPR/Cas9-mediated genome editing protocol for the genetic modification of PGCs derived from chickens with blue eggshell color. The sequence targeted in the present report is a provirus (EAV-HP) insertion in the 5’-flanking region of the SLCO1B3 gene on chromosome 1 in Araucana chickens, which is supposedly responsible for the blue eggshell color. We designed pairs of guide RNAs (gRNAs) targeting the entire 4.2 kb provirus region. Following transfection of PGCs with the gRNA, genomic DNA was isolated and analyzed by mismatch cleavage assay (T7EI). For absolute quantification of the targeting efficiencies in homozygous blue-allele bearing PGCs a digital PCR was established, which revealed deletion efficiencies of 29% when the wildtype Cas9 was used, and 69% when a high-fidelity Cas9 variant was employed. Subsequent single cell dilutions of edited PGCs yielded 14 cell clones with homozygous deletion of the provirus. A digital PCR assay proved the complete absence of this provirus in cell clones. Thus, we demonstrated the high efficiency of the CRISPR/Cas9 system in introducing a large provirus deletion in chicken PGCs. Our presented workflow is a cost-effective and rapid solution for screening the editing success in transfected PGCs.

Quality of table eggs in relation to shell colour

The present study evaluated the quality of table eggs in relation to shell colour. The study was conducted on 60 table eggs with shells coloured white, green, blue and brown (15 eggs per colour) obtained from laying hens from the same backyard farm. The following external quality traits of table eggs were measured: egg weight, percentage of dirty and cracked eggs, egg width and length, egg shape index, eggshell colour, eggshell weight and percentage, and eggshell thickness. The following internal quality indicators of table eggs were determined: albumen weight and percentage, albumen pH value, albumen width, length and height, Haugh index, albumen index, yolk weight and percentage, yolk pH value, yolk width and height, yolk index and yolk colour. Green eggs had the lowest weight, as well as the lowest width and length. White eggs had the highest eggshell dirtiness scores and egg shape index, while brown eggs had the highest eggshell thickness and weight. Green and brown eggs had the highest albumen index and Haugh index. In addition, green eggs had the lowest yolk width and the highest yolk index. White eggs had the highest albumen and yolk width, the greatest albumen length and the lowest albumen height. Yolks of white and blue eggs had a higher sensory colour score, as well as lower L* and b* values compared to the yolks of green and brown eggs. Based on the results of this study, it can be concluded that green and brown table eggs are of better overall quality compared to white and blue table eggs.

Study on egg sorting model based on visible-near infrared spectroscopy

To realize the automatic sorting of eggs, the sorting models are established in this paper by using the visible-near infrared spectroscopy technique and taking the eggshell colour, integrity, as well as the feeding mode as sorting indexes. A variety of methods are selected to remove the noise and systematic error by preprocess the spectral information. The backpropagation neural network (BP), the Principal Component Analysis (PCA) coupled with BP and the Soft Independent Modeling of Class Analogy (SIMCA) sorting method are used to identify the eggshell colours (white, pink, green), eggshell integrity (intact, cracked) and laying hen feeding mode (caged and cage-free) by their characteristic band, respectively. The prediction correlation coefficient (Rv), the prediction mean square error (RMSEP), the prediction standard error (SEP), the recognition rate () and the rejection rate () are used to evaluate the established models. The results show that the established classification models have high prediction accuracy and small errors. The non-destructive testing (NDT) technology has great potential for large-scale intelligent laying hen farms.

Traditional sexing methods and external egg characteristics combination allow highly accurate early sex determination in an endangered native turkey breed.

Early sex determination methods are not only crucial in the worldwide massive poultry industry, but also for small-holder producers. The profitability of sexing techniques must be accounted for when aiming to boost management, nutrition, and conservation practices in endangered poultry breeds. This becomes pivotal when the local breed dealt with belongs to an understudied species, such as the turkey. So, the main objective of this study is to identify which method combination may report a higher likelihood of successful sex determination in poults across the three-pattern varieties of the Andalusian turkey breed. A total of 84 one to two days old Andalusian turkey poults (42 black, 28 black-roan, and 14 bronze-roan) were evaluated in this study. Sex determination was performed using 15 methods, which included testing external egg metrics and eggshell color, poult morphological appraisal and phaneroptics, and behavioral traits. Possible differences across plumage varieties and the interaction between sex and plumage were observed when external egg quality was measured. Sex determination through behavioral methods in black base feathered (black and black-roan) male sex individuals showed seven times higher sensitivity when compared to the rest of the studied individuals (χ2 = 7.14, df = 1, P < 0.01). In contrast, for the black-roan plumage females, the method based on the color of down feathers was approximately four times more sensitive (χ2 = 3.95, df = 1, P ≤ 0.05). For the bronze-roan pattern, none of the sexing techniques was reported to efficiently predict sex itself. However, the most proper method combination to determine sex, independent of plumage color, was physical external egg characteristics, the color of down feathers, and behavioral approaches (“English method” and “slap technique”). The specificity values were found to be 49.12, 93.33, and 100%, while the sensitivity values were observed to be 74.64, 91.03, and 100%, which translated into accuracy of 63.10, 92.26, and 100% in black, black-roan, and bronze-roan poults, respectively. Our results suggest that the method combination tested in this study could be considered a highly accurate, simple, and affordable alternative for sex determination in turkeys. This could mean a pivotal advance for small producers of turkeys, as early sex detection can help to plan timely conservational management strategies, which is of prominent importance in the context of endangered poultry breeds.

Analysis of ultrastructure and microstructure of blackbird (Turdus merula) and song thrush (Turdus philomelos) eggshell by scanning electron microscopy and X-ray computed microtomography

The unique structure of the egg allows for efficient reproduction on land. Although the functions of the egg are ensured by the concomitant cooperation of all its structures, the eggshell also plays a significant role. Apart from maintaining an aqueous environment within the egg along with controlled gas exchange, the color and pigmentation pattern of eggshell contributes to identification and protection. As a result of all these functions, the structure, shape, and pigmentation of eggshell greatly vary across the class of birds, and understanding these three variability-determining factors may aid in better interpretation of evolutionary mechanisms. In this study, we analyzed for the first time the structure, mineral composition, and characteristics of the pigmentation of blackbird (Turdus merula) and song thrush (Turdus philomelos) eggshells. The shell of blackbird eggs is much thicker compared to the shell of song thrush eggs which is due to a much thicker crystalline and palisade layers. In both species, strongly elongated mammillary knobs are observed, which create a large space between the mineralized shell and the egg membranes. The blackbird egg shell has a higher water vapor conductivity which is due to the larger diameter of the circle and the surface area of individual pores. The primary compound entering the mineral composition of the shell in both species is CaCO3 however, the thrush egg shells contained more Mg in all layers except the crystalline layer, and S in the crystalline and palisade layers. The two species clearly differ in the size and distribution of pigment spots on the eggshell. We suppose that the differences in shell structure and pigmentation presented in this study may in the future provide a basis for explaining the reasons for the much lower reproductive efficiency of song thrush compared to blackbird.

Correlation between Internal and External Egg Quality Indicators in the Early Phase of Hy-Line Brown Laying Hens

This study investigated correlations between egg quality indicators to identify external egg quality traits to predict internal egg quality using non-destructive and convenient measurements. Thirteen indicators, including Haugh unit, albumen height, eggshell breaking strength, eggshell thickness, eggshell color (CIE L^*, CIE a^*, CIE b^*), and reflectivity value, egg weight, egg length, egg width, shape index, and yolk color, were investigated. A total of 180 brown eggs were obtained from one 27-week-old flock of Hy-line brown-laying hens raised in a cage system. Correlations were evaluated using Pearson’s correlation coefficient (r). The results showed strong correlations between Haugh unit and albumen height, eggshell color CIE L^* and reflectivity, egg weight and width, egg weight and length, eggshell color CIE L^* and CIE a^*, eggshell color CIE a^* and reflectivity, and shape index and egg length (<i>P</i>&lt;0.001). Moderate correlations were observed between eggshell breaking strength and eggshell thickness, eggshell color CIE a^* and CIE b^*, and shape index and egg width (<i>P</i>&lt;0.001). Eggshell color CIE L^* was correlated with eggshell breaking strength (<i>P</i>&lt;0.01), and eggshell color CIE a^* was correlated with Haugh unit, albumen height (<i>P</i>&lt;0.01), and eggshell breaking strength (<i>P</i>&lt;0.001). The present study showed significant correlations between eggshell color and other quality indicators. Thus, this study suggests that eggshell colors based on reflectiveness and the CIE L^*a^*b^* value can be used to estimate the Haugh unit, albumen height, eggshell breaking strength, and thickness.

Measurement of brown eggs freshness using non-destructive UV/VIS spectroscopy and viscosity of egg white

The present research aimed to determine the freshness of brown eggs using non-destructive ultraviolet-visible (UV/VIS) transmission spectroscopy (λ = 350-1020 nm) and viscosity measurement during storage for 7 days. As per human visual perception, the eggshell color varied from light yellow-brown to dark red-brown, distributed near the edge of the spectral locus of orange to a red region in the CIE 1931 chromaticity diagram. Quantitatively characterized luminance (CIE Y) values of the eggshell brightness were 7.77 (darkest) and 49.1 cd/cm2 (brightest). The L* value (brownness) of the eggshell increased while the a* value (redness) decreased. The correlation between luminance and transmittance values was evaluated using a linear regression model which showed a correlation coefficient of 0.92. The transmittance spectra collected daily showed a gradual increase from 36.0% (day 1) to 38.8% (day 3). The slope of this increment became steeper after day 3 and reached 50.8% (day 7). The freshness of the eggs calculated based on the transmittance value of 100% (day 1) showed an inverse relation with the storage time and was reduced by 59% (day 7). Egg white exhibited non-Newtonian shear thinning behavior and showed a reduction in viscosity by 13.7% reduction on day 7 as compared to that on day 1. Our results clearly demonstrated that the freshness of the eggs declined with an increase in storage time. This analytical method of measuring egg freshness has potential applications in designing an automatic egg selection machine, to identify stale eggs from the fresh ones on-site in small and medium egg farms by simply measuring the transmittance of eggshells of varying darkness.

Research Note: L*a*b* color space for prediction of eggshell pigment content in differently colored eggs

Eggshell color is the most intuitive external feature that affects consumer acceptance. Different eggshell colors are mainly determined by protoporphyrin IX and biliverdin content. The selection of eggshell color by the human eye with an eggshell color fan can be roughly classified. Although more technologically advanced, a colorimeter or spectrophotometer might be of limited use when observing a variety of shell colors, such as brown, olive, green, and blue. This study aimed to provide a convenient and accurate method for predicting the content of eggshell pigments by measuring eggshell color using the Commission International de L'Eclairage (CIE) L*a*b* system. The results showed the deepening of eggshell color in brown and blue eggs was correlated with increased eggshell pigment deposition, and eggshell color was significantly positively correlated with eggshell pigment content (P < 0.01). Furthermore, the adjusted R2 of the fitted function was in the range of 0.81 to 0.89, and the Spearman rank correlation coefficient between the predicted and true values was in the range of 0.89 to 0.93. In brief, the L*a*b* method of measuring eggshell color to predict the amount of eggshell pigment deposition is convenient, effective, and promising for layer production.

Long-term Feeding Effects of Calcium-bentonite Clay in Aflatoxin B1 Contaminated Diet on Egg Production, Egg Quality and Immune Status of Laying Hens

Background: This experiment was conducted to determine the effect of synthetic aflatoxin B1 and calcium bentonite clay as a mycotoxin binder in the laying hen diet on performance, egg quality and immune response to vaccination. Methods: A total of 144 Lohmann brown classic hens (22 weeks old) were divided into 4 groups of 6 replications with 6 hens each. This experimental design was completely randomized design and there were 4 experimental diets: (1) Basal diet (Positive control), (2) Basal diet +0.25% calcium bentonite clay, (3) Basal diet+200 ppb aflatoxin B1 (negative control) and (4) Basal diet+200 ppb aflatoxin B1 and +0.25% calcium bentonite clay. All hens were vaccinated with Newcastle (ND) and Infectious bronchitis (IB) vaccines during 24 weeks feeding trial. Result: At the end of the 24 weeks of feeding trial, dietary treatments did not influence the egg production, egg mass, feed conversion ratio (FCR) and IB titer of hens; however, aflatoxin B1 significantly (P less than 0.05) deceased final body weight and deceased the eggshell color score (P less than 0.05). Moreover, the ND titer was reduced by aflatoxin B1 at 8th and 12th weeks of trial (P=0.05 and less than 0.05; respectively). Thus, supplementation of 0.25% calcium bentonite clay in feed improved body weight, eggshell color and ND titer of laying hens similar to those fed the positive control diet.