Egg Color Research Articles

Quality assessment of chicken eggshell cuticle by infrared spectroscopy and staining techniques: a comparative study

ABSTRACT1. The cuticle is a very thin organic layer that coats the eggshell surface and plugs the eggshell pores preventing bacterial penetration. It also reduces eggshell permeability which is important to maintain internal quality of the egg. Thus, the eggshell cuticle quality is crucial to ensure the food safety and quality of eggs.2. A new methodology to assess eggshell cuticle quality, based on attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), is compared with a more traditional method based on cuticle staining techniques.3. Both techniques are useful to determine the amount of cuticle; however, the ATR-FTIR technique is independent of egg colour, more sensitive and provides complete information about the cuticle and its composition. Additionally, it provides information about eggshell permeability.4. The methodology for cuticle quality assessment described in this work can be very useful for genetic selection programmes aimed to improve the safety and quality of eggs.

Speckled and plain regions of avian eggshells differ in maternal deposition of calcium and metals: A hitherto overlooked chemical aspect of egg maculation

ABSTRACT Although it has been strongly implied that studies on structural function might resolve certain conflicting theories regarding the huge variability of coloration in avian eggs, including maculation, the fundamental physiological question about the functional role of eggshell speckling in the maternal deposition of micronutrients into maculated (pigment spots) and plain (unpigmented) eggshell regions remains largely unanswered. We measured (within the same egg) the concentrations of 2 micronutrients, the staple components of avian eggshells (calcium and magnesium), and 6 trace elements (copper, manganese, iron, cobalt, cadmium, and lead) in maculated (a superficial layer of brown pigment) and unpigmented areas of eggshells in 2 groups of Japanese Quail (Coturnix coturnix japonica) eggs representing 2 extremes of eggshell coloration: those with darker eggshells and more extensive pigment spots vs. those with bright eggshells and small, more clearly demarcated pigment spots. We found evidence that t...

Does contrast between eggshell ground and spot coloration affect egg rejection?

Obligate avian brood parasitic species impose the costs of incubating foreign eggs and raising young upon their unrelated hosts. The most common host defence is the rejection of parasitic eggs from the nest. Both egg colours and spot patterns influence egg rejection decisions in many host species, yet no studies have explicitly examined the role of variation in spot coloration. We studied the American robin Turdus migratorius, a blue-green unspotted egg-laying host of the brown-headed cowbird Molothrus ater, a brood parasite that lays non-mimetic spotted eggs. We examined host responses to model eggs with variable spot coloration against a constant robin-mimetic ground colour to identify patterns of rejection associated with perceived contrast between spot and ground colours. By using avian visual modelling, we found that robins were more likely to reject eggs whose spots had greater chromatic (hue) but not achromatic (brightness) contrast. Therefore, egg rejection decision rules in the American robin may depend on the colour contrast between parasite eggshell spot and host ground coloration. Our study also suggests that egg recognition in relation to spot coloration, like ground colour recognition, is tuned to the natural variation of avian eggshell spot colours but not to unnatural spot colours.

Does coevolution with a shared parasite drive hosts to partition their defences among species?

When mimicry imposes costs on models, selection may drive the model's phenotype to evolve away from its mimic. For example, brood parasitism often drives hosts to diversify in egg appearance among females within a species, making mimetic parasitic eggs easier to detect. However, when a single parasite species exploits multiple host species, parasitism could also drive host egg evolution away from other co-occurring hosts, to escape susceptibility to their respective mimics. This hypothesis predicts that sympatric hosts of the same parasite should partition egg phenotypic space (defined by egg colour, luminance and pattern) among species to avoid one another. We show that eggs of warbler species parasitized by the cuckoo finch Anomalospiza imberbis in Zambia partition phenotypic space much more distinctly than do eggs of sympatric but unparasitized warblers. Correspondingly, cuckoo finch host-races better match their own specialist host than other local host species. In the weaver family, parasitized by the diederik cuckoo Chrysococcyx caprius, by contrast, parasitized species were more closely related and overlapped extensively in phenotypic space; correspondingly, cuckoos did not match their own host better than others. These results suggest that coevolutionary arms races between hosts and parasites may be shaped by the wider community context in which they unfold.

Incubation and embryonic development affect the color of eggs of Mountain Bluebirds

Technological and theoretical advances over the past two decades have allowed researchers to quantify eggshell color in ways that were not previously possible. However, differences among studies in the timing of color measurements during laying or incubation and inclusion of data from inviable eggs may affect the results of these studies as well as conclusions based on comparisons among studies. To determine the effect of the timing of color measurements, we compared the color of the eggs of Mountain Bluebirds (Sialia currucoides) during both laying/early incubation and late incubation. We also assessed the influence of egg viability on eggshell color by comparing viable and inviable eggs from the same clutch. We found that all color metrics investigated (blue-green and UV chroma, brightness, and hue) were significantly different between early and late incubation, and viable and inviable eggs. However, color metrics of eggs measured during early and late incubation and of viable and inviable eggs in the same clutch were correlated. Our results suggest that the timing of color measurements and the viability of eggs have important effects on eggshell color and, therefore, in future studies, investigators should always provide information about the timing of measurements and the viability of eggs measured. Our results also suggest that comparisons among studies where eggshell color was measured at different times and/or the viability of eggs was not determined or reported are possible, given that the color metrics of viable and inviable eggs and of eggs measured at different times in our study were correlated, but those comparisons should be interpreted with caution.

Breeding behavior of the Atlantic forest endemic Blue Manakin (Chiroxiphia caudata)

ABSTRACT.— Manakins are small frugivorous birds found in the understory of humid Neotropical forests. Although aspects of their complex sexual displays have been addressed in various studies, their nesting biology is poorly documented. The Blue Manakin (Chiroxiphia caudata) is characterized by a cooperative courtship display but knowledge about its reproduction is limited to descriptions of the nest and eggs. We investigated 36 active nests during two breeding seasons in a well-preserved stretch of Atlantic Forest in southeastern Brazil. Nests were shallow cups attached at their rim to horizontal forks in bushes or saplings with slender branches and were usually built over or close to forest streams. Reproductive activities were recorded from October to February and clutches were invariably consisted of two eggs. The incubation period was 18 days; nestling periods varied from 15 to 16 days, and estimated overall nesting success was 34%. Comparisons of nest architecture, egg color, and nestling characteris...

Egg discrimination along a gradient of natural variation in eggshell coloration.

Accurate recognition of salient cues is critical for adaptive responses, but the underlying sensory and cognitive processes are often poorly understood. For example, hosts of avian brood parasites have long been assumed to reject foreign eggs from their nests based on the total degree of dissimilarity in colour to their own eggs, regardless of the foreign eggs' colours. We tested hosts' responses to gradients of natural (blue-green to brown) and artificial (green to purple) egg colours, and demonstrate that hosts base rejection decisions on both the direction and degree of colour dissimilarity along the natural, but not artificial, gradient of egg colours. Hosts rejected brown eggs and accepted blue-green eggs along the natural egg colour gradient, irrespective of the total perceived dissimilarity from their own egg's colour. By contrast, their responses did not vary along the artificial colour gradient. Our results demonstrate that egg recognition is specifically tuned to the natural gradient of avian eggshell colour and suggest a novel decision rule. These results highlight the importance of considering sensory reception and decision rules when studying perception, and illustrate that our understanding of recognition processes benefits from examining natural variation in phenotypes.

Pengaruh Penggunaan Tepung Limbah Udang dalam Ransum terhadap Kualitas Telur Itik

<p class="p1">The research aimed to determine the effect of shrimp waste on the quality of duck eggs. The research used 80 female ducks aged 21 weeks which were randomly distributed into four treatments consisted of four replicates of 5 ducks each. The ration consisted of yellow corn, rice bran, soybean meal, fish meal, premix, grit, vegetable oil and shrimp waste. The dietary treatments were formulated to contain 0 (control), 3, 6, and 9% shrimp waste. The experiment was performed for 3 periods of 28 days. Egg quality was assessed for 3 consecutive days on d 26,27 and 28 of every periods. The data were analysed using Analysis of Variance and continued with Duncan’s test for different results. Theuse of 9% shrimp waste in ration increased (P<0.05) score of yolk colour from 6.94 to 7.79, but did not affect other measured variables. It can be concluded that shrimp waste enhanced yolk colour of duck eggs.</p>

Pengaruh Penggunaan Tepung Limbah Udang dalam Ransum terhadap Kualitas Telur Itik

<p class="p1">The research aimed to determine the effect of shrimp waste on the quality of duck eggs. The research used 80 female ducks aged 21 weeks which were randomly distributed into four treatments consisted of four replicates of 5 ducks each. The ration consisted of yellow corn, rice bran, soybean meal, fish meal, premix, grit, vegetable oil and shrimp waste. The dietary treatments were formulated to contain 0 (control), 3, 6, and 9% shrimp waste. The experiment was performed for 3 periods of 28 days. Egg quality was assessed for 3 consecutive days on d 26,27 and 28 of every periods. The data were analysed using Analysis of Variance and continued with Duncan’s test for different results. Theuse of 9% shrimp waste in ration increased (P<0.05) score of yolk colour from 6.94 to 7.79, but did not affect other measured variables. It can be concluded that shrimp waste enhanced yolk colour of duck eggs.</p>

PHENOTYPIC CHARACTERISTICS AND BIOMETRICAL STUDY ON DIFFERENT BREEDS OF PIGEON IN NORTHERN BANGLADESH

The experiment was conducted to characterize different breeds of pigeon phenotypically and to study their body biometry, which are available in the northernBangladesh. During this study 30 farms were selected which have >20 pair of pigeons in the three study area namely Rajshahi, Natore and Pabna districts ofBangladesh. There about 15 breeds have been selected for the observation of phenotypic characteristics such as color of bill, eye, eyelid, skin, shank, toe, egg, head feather, neck feather, body feather, down feather, wing feather, tail feather and shape of bill, body and egg. The biometrical data were collected from the measurement of length of bill, head, body, shank, middle toe, wingspan and mature body weight. In this study the highest mean bill length was found 2.83±0.05cm in Strasser and lowest mean head length 5.00±0.00cm in Kormona, Nun and Jacobin. The highest mean body length was found 41.60±0.38cm in Strasser and lowest mean body length 30.00±0.43cm in Owl. The highest mean wingspan was found 81.00±0.51cm in Jacobin and lowest mean wingspan 60.45±0.76cm in kormona. The heighest mean shank length was found 3.40±0.13cm in Homer and lowest mean shank length 2.50±0.00cm in Giribug, Kormona, Nun, Satinette and Suachandan. The heighest mean middle toe length was found 4.40±0.05cm in pouter and lowest mean middle toe length 3.00±0.00cm in kormona. The heighest mean mature body weight was found 748.20±8.96gm in Strasser and lowest mean mature body weight 265.10±7.03gm in Giribug. Phenotypic correlation among bill length, head length, body length, wing span, shank length, middle toe length and mature body weight of these breeds of pigeon ranged from 0.233 to 0.789. The experiment’s result may contribute to breed up gradation, helps to formulate the conservation and improvement strategies for the breed as genetic resource.

Nesting Biology of Carmiol's Tanager (Chlorothraupis carmioli frenata) In Southeastern Peru

ABSTRACT We provide the first detailed account of incubation and nesting behaviors of Carmiol's Tanagers (Chlorothraupis carmioli) based on 34 nests of the subspecies Chlorothraupis carmioli frenata found between 2008 and 2011 in Manu National Park at 400 and 1100 m above sea level. All nests were shallow cups with three layers. All nests had two white eggs with varying intensity of brown speckling. The parent spent 63.9 ± 11.6% (average ± SD) of the daylight period incubating and conducted 5.6 ± 2.3 (n = 73 days) off-bout trips per day that lasted 52.6 ± 22.9 min (n = 409 trips). The incubation period ranged from 15 to 17 days. Nestlings hatched weighing on average 4.2 ± 0.8 g (n = 8 nestlings) and gained 2.5 ± 0.1 g per day (n = 63 nestling-days). The nestling period lasted 11 days. Mass the day before fledging was 24.7 ± 2.1 g (n = 3 nestlings). Nest shape and composition, egg coloration, and clutch size of C.c frenata subspecies was very similar to the nests described for Central American subspecies C...

Key to the Species of Ukrainian Notodontid Moths (Lepidoptera, Notodontidae) On the Egg Characters

Abstract A key for identification of 39 species from 20 genera of Ukrainian notodontid moths based on the the eggs is provided. Reliable diagnostic characters, which do not disappear with the injury of eggs or eggs preserved for a long time in alcohol were used. The characters as egg shape, egg and chorion colour, shape of gnawed holes in eggs before setting out of caterpillars, the type of oviposition and the chorionic sculpture are applied. Clear characters that are typical for the live eggs, which vary in the process of egg development are revealed. These are characters of egg colour and pattern. In the key such characters are kept by stable signs that do not disappear aft er eggs traumatizing. The key is illustrated in details with photographs made using a digital camera and scanning electron microscope.

Patterns and Drivers of Egg Pigment Intensity and Colour Diversity in the Ocean: A Meta-Analysis of Phylum Echinodermata.

Egg pigmentation is proposed to serve numerous ecological, physiological, and adaptive functions in egg-laying animals. Despite the predominance and taxonomic diversity of egg layers, syntheses reviewing the putative functions and drivers of egg pigmentation have been relatively narrow in scope, centring almost exclusively on birds. Nonvertebrate and aquatic species are essentially overlooked, yet many of them produce maternally provisioned eggs in strikingly varied colours, from pale yellow to bright red or green. We explore the ways in which these colour patterns correlate with behavioural, morphological, geographic and phylogenetic variables in extant classes of Echinodermata, a phylum that has close phylogenetic ties with chordates and representatives in nearly all marine environments. Results of multivariate analyses show that intensely pigmented eggs are characteristic of pelagic or external development whereas pale eggs are commonly brooded internally. Of the five egg colours catalogued, orange and yellow are the most common. Yellow eggs are a primitive character, associated with all types of development (predominant in internal brooders), whereas green eggs are always pelagic, occur in the most derived orders of each class and are restricted to the Indo-Pacific Ocean. Orange eggs are geographically ubiquitous and may represent a 'universal' egg pigment that functions well under a diversity of environmental conditions. Finally, green occurs chiefly in the classes Holothuroidea and Ophiuroidea, orange in Asteroidea, yellow in Echinoidea, and brown in Holothuroidea. By examining an unprecedented combination of egg colours/intensities and reproductive strategies, this phylum-wide study sheds new light on the role and drivers of egg pigmentation, drawing parallels with theories developed from the study of more derived vertebrate taxa. The primary use of pigments (of any colour) to protect externally developing eggs from oxidative damage and predation is supported by the comparatively pale colour of equally large, internally brooded eggs. Secondarily, geographic location drives the evolution of egg colour diversity, presumably through the selection of better-adapted, more costly pigments in response to ecological pressure.

Brood Parasitism Defense Behaviors Along an Altitudinal Gradient in the American Robin (Turdus Migratorius)

Some host species accept eggs from brood parasites over parts of their range and reject them in other areas representing an “evolutionary lag” in the development of rejection behavior or the loss of an adapative behavior when the selection pressure of brood parasitism is removed. Hosts may deter brood parasitism through egg rejection and aggressive nest defense behavior specifically targetting female brood parasites during the egg incubation period. In areas where parasitism frequencies are spatially and temporally variable, anti-parasite behaviors may decline as costs outweigh the benefits. Along the Colorado Front Range, American robins (Turdus migratorius) breed from low elevations where the brood parasitic Brown-headed Cowbird (Molothrus ater) is abundant to near timberline (3700 m) where cowbirds are uncommon. We tested the hypothesis that egg rejection and nest defense behaviors decline with reduced probability of parasitism. We found that robins accepted 100% of immaculate (robin-like) experimental eggs at both low and high elevations, but were more likely to reject spotted (cowbird-like) experimental eggs at low elevations than high elevations. Response to egg size was more variable than to egg color. When presented with a mount of a cowbird and Song Sparrow (Melospiza melodia) near the nest, robins responded more aggressively to cowbird models than to sparrows (control), and nest defense behavior towards cowbirds was longer and more aggressive at the lower elevation sites where cowbirds are common. These results suggest that egg rejection and nest-site aggression are costly adaptations to cowbird parasitism, and these behaviors decline when the threat of parasitism is reduced.

Temperature and shelving period effect on albumin height and color of supermarket eggs sold in northwest Mexico

Changes in albumin height and yolk color of supermarket eggs were determined by a regression model with dummy variables after periods of 1, 3 and 6 days. A first group included eggs stored above 25 ºC, while the second included eggs stored below 25 ºC. It was found that although on day one, eggs in both group were classified in the highest quality category, after six days a reduction in albumin height placed both groups in the second quality classification. However, it was found that percentage loss for group below 25 ºC was smaller than reduction in group above 25 ºC. Percentage of change in yolk color measured by L* a* and b* was smaller for the group above 25 ºC. Results indicate that when temperature in a supermarket reaches 25 ºC or more, eggs should not be stored for more than six days.

THE PHENOTYPIC AND PRODUCTIVE CHARACTERIZATION OF BENHA-LINE CHICKEN UNDER EGYPTIAN CONDATIONS

This project started in 2008 and aimed to produce a synthetic line of chickens under hot climate conditions in Egypt. A description of the main features of the line Benha chickens (Line B) is carried out. It was founded in 2011 as a synthetic line between the Egyptian Golden Montazah (50%) and the White Leghorn (50 %). The procedure of foundation began mating Golden Montazah cocks to White Leghorn hens and it was followed by three generations of “inter se” mating. Afterwards the line has been selected to highly egg production and quality according to the predicted breeding values based the BLUP procedure using animal model.The phenotypic and productive characters for this line are recorded. The main characteristics of this line are: Feather colors in adult chickens were mostly White (70%), 15% red golden and 15% grey, good adaptation for hot climate conditions (25-35 oC). It has high resistance for Pasteurellosis and Salmonella diseases, high fertility (93%) and hatchability (86%), low mortality rate (1%) during the production period, moderate body weight at sexual maturity (1742 g) and age at sexual maturity 159.6 d, high annual egg production (230 egg), moderate egg weight (55 g), white egg color, egg shape index was 79.1%, high Haugh units (93.8 %), live body weight was 1970 g and 1269 g for males and females respectively, carcass weight was 1273 g for cocks and moderate dressing percentage (65%). Thus, the B-line has showed high productive traits under hot climate conditions in Egypt.

Advances on tinamou phylogeny: an assembled cladistic study of the volant palaeognathous birds.

Tinamous are volant terrestrial birds, endemic to the Neotropics. Here, an inclusive phenotype-based phylogenetic study of the interrelationships among all extinct and living species of tinamous is conducted. In this cladistic analysis, results are compared between main character subsets and with previous molecular studies. Special attention is paid to character definition and scoring of integumentary and behavioural characters: transformation costs are applied to analyse egg coloration and plumage characters-on the basis of pigment composition and overlap of pigmentation patterns respectively-in the context of generalized (Sankoff) parsimony. Cladistic analysis recovers the traditional subdivision between those tinamous specialized for open areas (Nothurinae) and those inhabiting forested environments (Tinaminae) and support the monophyly of recognized genera. The present study demonstrates that morphological analysis yields highly congruent results when compared with previous molecular studies; thus, it provides morphological synapomorphies for clades that have been proposed by these molecular analyses. The placement of the fossil species within the open-area (Nothurinae) and the forest-dwelling (Tinaminae) tinamous is also consistent with the palaeoenvironmental conditions inferred from the associated flora and fauna.

Sensor for Detecting Caviar Maturity in Farmed Sturgeon

<abstract> Depletion of wild sturgeon around the world has forced the transition from wild-caught to farm-raised caviar. Farmers face difficult challenges to produce eggs of sufficient size and firmness to yield high-quality caviar at reasonable production costs. Females reach sexual maturity at about seven years, and the oocytes (eggs) are examined by surgical biopsy of the ovary in the late fall for color and size. Egg harvest follows in the winter and spring, but the exact time to harvest optimum quantity and quality of caviar cannot be predicted based on egg size or color because of individual variations in the rate of egg development. Changes in the concentration of plasma vitellogenin, a yolk precursor protein, reflect growth of the eggs and the transition to final maturation. Total plasma calcium is highly correlated with vitellogenin concentration. An automated sensor was designed to measure calcium in sturgeon blood plasma by chemical assay. The sensor used solenoid-operated, fixed-volume pumps, and solenoid-operated valves and was run with an embedded controller. It was able to measure total calcium (free and bound ions) in white sturgeon blood plasma with adequate accuracy to distinguish vitellogenic from non-vitellogenic fish. The sensor was tested in late fall during the normal commercial screening to identify ripe sturgeon. The readings were used to separate half of the ripe fish into low and high calcium groups based on plasma levels previously reported in the literature. The remainder of the ripe fish were used as the control. The harvest groups were selected to compare yields from groups of fish harvested under the current practice (random harvest from winter to spring) and groups harvested based on plasma calcium. Our hypothesis was that caviar harvesting based on plasma calcium gives more uniform size and yield compared to random harvesting, which is the current practice. The early harvest group and low calcium group were sampled in March, and the late harvest group and high calcium group were sampled in May. The high calcium group had greater yield per body mass than the low calcium and early harvest groups. No differences were found in body mass, fork length, ovary mass, egg diameter, and caviar yield. Only one fish was found to be atretic, and that individual was in the early harvest group. These results suggest that a better strategy might be to delay the current time of harvest by several months, with the higher calcium fish processed last.

Reproductive biology of the three-spot swimming crab (Portunus sanguinolentus) from the west coast of Sri Lanka with a novel approach to determine the maturity stage of male gonads

Aspects of the reproductive biology of Portunus sanguinolentus from the west coast of Sri Lanka were studied from February 2014 to January 2015. Berried females were observed throughout the year, confirming that they were continuous spawners; however, peak spawning was in October. The gonadosomatic index of females was significantly higher than the males (GLM; p < 0.05). Sex ratio fluctuated seasonally and a significantly higher male to female ratio was observed in October (χ2 test). Size at first sexual maturity was estimated at 9.75 and 9.40 cm carapace width for males and females, respectively. Three types of external egg masses, stages I, II and III, were identified based on the colour of berried eggs. The mean (±SD) diameter of eggs in each stage was 253.8 ± 3.19, 281.8 ± 6.79 and 316.5 ± 9.78 μm, respectively. The estimated fecundity of P. sanguinolentus varied from 1.12 × 105 to 1.38 × 106. We propose a new method to identify the maturity stage of the male gonad using external characteristics. Males with mature gonads have blue colour patches on the ventral side of the chelar propodus and merus but this was not prominent in males with immature gonads and absent in females.

Are Egg Colors and Patterns Signs of Phylogenetic Relatedness in Parrotbills?

Abstract Egg colors and patterns have long been of interest for ornithologists and evolutionary biologists, with several hypotheses proposed to explain them. These include: Wallace's hypothesis, the structure hypothesis, the brood parasitism hypothesis and the post-mating sexual selection signal hypothesis. However, none of these are sufficient to elucidate the evolutionary mechanism involved. In this study, egg polymorphism and phylogenetic relationships within the avian family Paradoxornithidae were investigated. When compared with phylogenetic information, we found that egg color matched two size-related clades within the Paradoxornithidae. The larger parrotbills all lay patterned eggs with pale background colors, whereas the smaller parrotbills lay plain pale blue eggs. To our knowledge, this is the first study to detect such a relationship between egg color and pattern and phylogeny in parrotbills, suggesting that they are under strong phylogenetic constraints and can be treated as an important indic...