Egg Color Research Articles

Character displacement of egg colors during tinamou speciation.

The divergence of reproductive traits frequently underpins the evolution of reproductive isolation. Here we investigated whether tinamou (Tinamidae) egg colorations function as mating signals that diverged as character displacement (mating signal character displacement hypothesis). We tested three evolutionary predictions behind the hypothesis: (a) egg colors coevolve with known mating signals; (b) signal divergence is associated with divergent habitat adaptation; and (c) sympatric tinamou species with similar songs have different egg colors as character displacement during speciation. We found support for all three predictions. In particular, egg colors coevolved with songs; songs and egg colors coevolved with habitat partitioning; and tinamou species that were likely sympatric with similar songs tended to have different egg colors. In conclusion, the mating signal character displacement hypothesis is well supported in which egg colors serve as mating signals that undergo character displacement during tinamou speciation.

Revealing the roles of egg darkness and nest similarity for a cryptic parasite egg versus host's cognition: an alternate coevolutionary trajectory.

As a text-book example of coevolution, the escalating interactions between egg mimicry by parasitic cuckoos and egg recognition by their hosts constitute a key battlefield for parasitism and anti-parasitism strategies. However, some parasite-host systems have deviated from this coevolutionary trajectory because some cuckoos do not lay mimetic eggs, while the hosts do not recognize them, even under the high costs of parasitism. The cryptic egg hypothesis was proposed to explain this puzzle, but the evidence to date is mixed and the relationship between the two components of egg crypticity, egg darkness (dim egg coloration) and nest similarity (similarity to host nest appearance), remains unknown. Here, we developed a 'field psychophysics' experimental design to dissect these components while controlling for undesired confounding factors. Our results clearly show that both egg darkness and nest similarity of cryptic eggs affect recognition by hosts, and egg darkness plays a more influential role than nest similarity. This study provides unambiguous evidence to resolve the puzzle of absent mimicry and recognition in cuckoo-host systems and explains why some cuckoo eggs were more likely to evolve dim coloration rather than similarity to host eggs or host nests.

Morphological Characteristics and Reproductive Organs Assessment of Blue-Spotted Mudskipper Boleophthalmus Boddarti in Peninsular Malaysia

Mudskippers have a unique adaptation allowing them to live on the land and commonly inhabiting the mangrove ecosystem. A fundamental study on the Blue-spotted mudskippers, Boleopthalamus boddarti were purposely to identify the species through morphometric and meristic characteristics, observation on the gonad organs as well as to correlate with their length-weight relationship. Collection of B. boddarti (n=72) from Matang Perak, Pendas Johor and Pekan Pahang was conducted using hand and net. Data collection on seventeen morphometric and seven meristics characters, length and weight, and pictorial documentation on male and female gonads were conducted. The means of each characteristic were estimated by using analysis of Variance (ANOVA) with P<0.05. The morphometric analysis found eye diameter and posterior dorsal fin ray count characteristics were significantly different (P<0.05) followed by five meristics characteristics except for anterior dorsal fin ray count and upper jaw teeth characteristics (F value ≥ 1.0). The mature gonad of female B. boddarti was found with an ovary in bright yellow coloration, turgid, firm and visible presence of eggs. Male gonads were identified with a testis having two lobes, a swollen structure at the top of the elongated shape and appear pale pink and thicker than the immature testes that generally exist in string-like structures. The length and weight of the fish were found directly proportional to the regression curve displayed b≠3. Morphometric and meristic characteristics were a reliable method in the identification of fish in general and for B. boddarti in specific. The observation of gonads differentiation helps understand the mature and immature state of the sex organs. This study offered an easy, quick and low-cost approach in determining species and sexes compared to the molecular method.

Assessment of Embryonic and Larval Development of Nile Tilapia under the Traditional and Re-Circulatory Thermostatic System in Relation to Climatic and Water Quality Variations

Embryonic and larval development of tilapia (Oreochromis niloticus) is very vulnerable to climate change. This study was conducted for an assessment of the embryonic and larval development of Nile tilapia in traditional hatchery and re-circulatory thermostatic systems. Daily changes in embryonic and larval development were measured through microscopic observation and image analysis in the laboratory. Climatic data and water quality parameters were measured every day using appropriate devices. Water temperature was varied with room temperature at the traditional hatchery system while it was maintained at 28.50 °C in the re-circulatory thermostatic system. A total of 200 unhatched eggs were stocked in every three trays of both systems. The egg diameters of the gastrula, segmentation, and pharyngula stages were measured at higher (2261.47 ± 81.66 µm, 2646.24 ± 17.98 µm, and 2710.90 ± 16.60 µm) in the re-circulatory thermostatic system than in the traditional hatchery system (2261.07 ± 81.52 µm, 2645.47 ± 18.24 µm, and 2710.01 ± 16.45 µm), respectively. For both systems, egg colors, egg size, black pigments, germinal ring, eye shape, tail, and heartbeat were determined through microscopic observation. Higher hatching and survival rates were found under the re-circulatory thermostatic system (95% and 97%) than under the traditional hatchery system (85% and 81%). About 6 h less hatching time was required under the re-circulatory thermostatic system than under the traditional system. At the end of 30 DAH (Days After Hatching), larval length and weight under the re-circulatory thermostatic system were found to be higher (15.736 ± 0.424 mm and 0.0528 ± 0.004 g) than under the traditional hatchery system (15.518 ± 0.415 mm and 0.050 ± 0.004 g), respectively. Larval growth patterns for both systems were found to have an exponential trend. PCA analysis revealed that two components were identified, one primarily associated with morphometric characteristics and the other with climatic and water quality parameters. These components showed that there were several interrelationships between the morphometric changes and the climatic and water quality parameters. The characteristic changes of larval development under the re-circulatory thermostatic system and the traditional hatchery system were found to be remarkably similar except for some deformities denoted under the traditional hatchery system. The changes of yolk sac, body pigmentation, dorsal and caudal fin shape, eye size, and head length and width were determined from 1 DAH to 30 DAH. After absorbing the yolk sac, ready-made feed was provided. The water temperature was varied from 30.50 °C to 35.50 °C in the traditional hatchery system. The highest air temperature and humidity were 33.87 °C and 69.94% while the lowest were 29.63 °C and 45.62%, respectively, in the traditional hatchery system. There has been no such comprehensive comparative study on hatchery production in Bangladesh, and therefore, further research might be carried out on broader aspects. This research would be highly beneficial for improving seed production at the tilapia fish hatchery level in the country.

Dietary supplementation of Spirulina platensis and Saccharomyces cerevisiae on egg quality, physiological condition and ammonia emission of hens at the late laying period

The study was aimed to evaluate the effect of Spirulina platensis and Saccharomyces cerevisiae or its combination on egg quality, physiological condition and ammonia excretion of hens at the late lay-ing period. At 81 weeks old, 144 Lohmann Brown layer chickens were divided into four treatment groups included CON (hens fed basal feed), SP (basal feed + 0.3% S. platensis), SC (basal feed + 0.2% S. cerevisiae), and SPSC (basal feed + 0.3% S. platensis + 0.2% S. cerevisiae). At the end of the study, eggs, intestinal mucosa, digesta, excreta and blood sample were collected. Results showed that albumin index was higher (P<0.05) in SPSC group than in CON, SP and SC. The yolk index and yolk colour were greater (P<0.05) in SP and SPSC groups than in CON and SC. The erythrocyte values were high-er (P<0.05) in SP group compared to CON, SC and SPSC groups. The ileum pH was higher (P<0.05) in SP than in CON, SC and SPSC. Lactic acid bacteria counts were lower (P<0.05) in the caecum of SC and SPSC than in CON and SP groups. The lower (P<0.05) counts of lactose-negative Enterobacte-riaceae were shown in SC and SPSC than in CON. The excreta pH was lower (P<0.05) in SC group compared to CON, SP and SPSC groups. There were better (P<0.05) protein digestibility coefficient and nitrogen retention in SPSC group than others. Faecal ammonia decreased (P<0.05) in SP, SC and SPSC groups. In conclusion, S. platensis improved egg yolk index and colour, increased erythrocyte counts and played an important role in maintaining the balance of bacteria in the intestine resulting in reduced ammonia excretion. Dietary inclusion of S. cerevisiae reduced ammonia excretion of laying hens during the late laying period.

Experimental evidence that cuckoos choose host nests following an egg matching strategy.

The arms race between brood parasites and their hosts provides a classic model to study coevolution. Hosts often reject the parasitic egg, and brood parasites should therefore select host nests in which the colour of the eggs best matches that of their own. Although this hypothesis has received some support, direct experimental evidence is still lacking. Here, we report on a study of Daurian redstarts, which show a distinct egg-colour dimorphism, with females laying either blue or pink eggs. Redstarts are often parasitized by common cuckoos, which lay light blue eggs. First, we showed that cuckoo eggs were more similar in spectral reflectance to the blue than to the pink redstart egg morph. Second, we report that the natural parasitism rate was higher in blue than in pink host clutches. Third, we performed a field experiment in which we presented a dummy clutch of each colour morph adjacent to active redstart nests. In this set-up, cuckoos almost always chose to parasitize a blue clutch. Our results demonstrate that cuckoos actively choose redstart nests in which the egg colour matches the colour of their own eggs. Our study thus provides direct experimental evidence in support of the egg matching hypothesis.

Attractive egg color? Red eggs facilitate egg acceptance in a cavity-nesting host.

Attractive egg color? Red eggs facilitate egg acceptance in a cavity-nesting host.

Consumer preferences for the color of unprocessed animal foods.

Consumer choices for food products are often based on appearance; one important aspect being product color. We systematically review the literature on consumer preferences for the color of raw beef, pork, poultry, bee honey, cow milk, and chicken eggs to inform future food technology and marketing research; a total of 40 studies were identified. Consumer preferences for pork color vary widely globally and can depend on other demographic factors. A trend toward light and bright beef was observed in six out of eight studies. A pink color was preferred in chicken by consumers in Northern Ireland and Brazil; muscle color uniformity was also related to higher acceptance. Contrarily, a diverse selection of honey colors is preferred; dark golden, yellow, and amber products were liked by consumers across the globe. One study observed a preference for white (over yellowish) milk. Worldwide, white and brown eggshells are preferred nearly equally with considerable differences between continents and regions. Our review highlights the heterogeneity of color preferences for animal products, worldwide; research methods should focus on quantifying colors associated with preferences so that food producers can accurately market their diverse products in regions with corresponding color preferences.

Determination of vitamin D level in chicken eggs from conventional and free range systems

This study aimed to investigate the vitamin D levels and some quality features of eggs. A total of 150 eggs (75 conventional and 75 free-range) were selected for the study. The levels of 25-OH vitamin D were determined by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in egg yolks. Furthermore, we evaluated the weights of egg, yolk, albumen, and yolk color as well as shape index, shell thickness, and percentages of albumen, yolk, and shell. The 25-OH vitamin D levels were significantly higher (P < 0.01) in the conventional than in the free-range eggs. Furthermore, the weights of egg, albumen, yolk, percentage of yolk and yolk color were significantly higher (P < 0.01) in the conventional than in the free-range eggs. However, the shape index, percentage of albumen, percentage of shell and shell thickness were significantly higher (P < 0.01) in the free-range than the conventional eggs. It can be concluded that vitamin D levels in eggs can be related to yolk color. However, egg quality characteristics can also be influenced by various environmental factors.

The Effect of Ethanol Propolis Extracts on Inhibition of Growth of Fusarium solani on Hen Eggs

The inhibition of growth of Fusarium solani mold on the shells of coated table hen eggs of a ethanol extract of propolis was investigated. Hen eggs were inoculated with F. solani spores and then coated with propolis extract at a concentration of 1, 2, 3, 5 or 10% using the spray method. Hen eggs were stored at room temperature for 28 days. Weight loss and the color of coated hen eggs were checked during storage. The color of hen eggs was tested using the CIELab method. Propolis extract was found to inhibit the growth of F. solani on hen eggshells. A reduction of three log cycles in the number of molds was observed on hen eggs coated with 10% propolis extract. Coating hen eggs with propolis extract slowed down and limited weight loss. No statistically significant changes in color parameters or sensory characteristics were observed during storage of hen eggs. There was a slight smell of propolis on the shells of hen eggs. Spraying table hen eggs with propolis extract at a concentration of 10% can help to improve the microbiological safety of hen eggs in terms of anti-mold protection.

First documented case of Tawny Pipit &lt;em&gt;Anthus campestris&lt;/em&gt; nest parasitism by Common Cuckoo &lt;em&gt;Cuculus canorus&lt;/em&gt; in Spanish steppes

Interspecific brood or nest parasitism is a relatively common breeding behavior in birds. Through this reproductive tactic, brood-parasites avoid the costs associated with raising and maintaining chicks by laying their eggs in the nests of the host species in which they are specialized. The common cuckoo (Cuculus canorus) follows this brood parasite strategy. Female cuckoos lay their eggs in the nests of other bird species, mimicking egg shape, size, and color of the host species. In this paper we report the first documented case of parasitism of tawny pipit nests by the common cuckoo in Spanish steppe habitats, where no record of parasitism on this species has been reported to date.

New breeding information on Brazilian birds. 1: Rheidae, Tinamidae, Anhimidae, Anatidae, Cracidae and Podicipedidae

This is the first in a planned series of articles about the breeding behaviour of Brazilian birds. Field work has been carried out in various regions of Brazil since the 1980s. The descriptions cover various aspects of reproductive biology, such as seasonality, nest architecture, materials and measurements, clutch size, egg colour, size and shape, incubation period, nestling period, and parental care. Many data are presented scientifically for the first time. In this first paper, we present data for 16 species: Greater Rhea Rhea americana (two nests, including the first information from north-east Brazil), Small-billed Tinamou Crypturellus parvirostris (20 nests), Red-winged Tinamou Rhynchotus rufescens (three nests), Spotted Nothura Nothura maculosa (11 nests), Horned Screamer Anhima cornuta (four nests, possibly with the first biometrics of eggs in the wild from Brazil), Southern Screamer Chauna torquata (five nests), White-faced Whistling Duck Dendrocygna viduata (three nests), Black-bellied Whistling Duck D. autumnalis (eight nests), Muscovy Duck Cairina moschata (two nests), Brazilian Teal Amazonetta brasiliensis (one nest), White-cheeked Pintail Anas bahamensis (one nest), Rusty-margined Guan Penelope superciliaris (seven nests, probably with the first data on reproductive success), Chaco Chachalaca Ortalis canicollis (one nest), East Brazilian Chachalaca O. araucuan (one nest), Least Grebe Tachybaptus dominicus (six nests) and Pied-billed Grebe Podilymbus podiceps (one nest).

Growth Rate and Sexual Performance of Domesticated Blue Swimming Crab, Portunus pelagicus (Linnaeus, 1758) in Earthen Ponds

It is generally accepted that using domesticated aquatic animal is advantageous due to their adaptation to a captive environment. Despite previous reports on the domestication of the blue swimming crab, Portunus pelagicus (Linnaeus 1758), empirical data are lacking on the growth and sexual performance of domesticated individuals of this crab species. Thus, the growth and sexual performance were evaluated of domesticated P. pelagicus from the 1st to the 3rd generations. Domesticated crabs in the 1st (G1), 2nd (G2) and 3rd (G3) generations were reared for 150 days in 400 m2 earthen ponds at a density of 2 crabs/m2. Each generation had 3 replicates. The performance results showed that the mean final CW (11.4 cm) of G1 was higher than in G3 (9.9 cm), and G1 had a higher mean final BW (123.4 g) and SGR (4.8 % day–1) than in G2 (108.2 g and 4.7 % day–1, respectively) and G3 (102.9 g and 4.7 % day–1, respectively). The mean SR values in G1 (20.2 %), G2 (18.8 %) and G3 (18.3 %) were not significantly different. No significant differences were observed in mean FCR and productivity in G1 (5.8 and 94.1 kg/pond, respectively), G2 (6.6 and 82.9 kg/pond, respectively) and G3 (6.7 and 82.0 kg/pond, respectively). Sexual dimorphism in G1, G2 and G3 was observed at 60 days of rearing, with the sex ratio being 1:1 in each generation and 5.6 and 6.7 % of female crabs in G2 and G3, respectively, being berried in this period. In contrast, the berried females in G1 (17.6 % of females) were 1st found on day 90 of the rearing period. At day 150, the percentage composition ranges for yellow, brown and dark gray egg colors of the reared berried female crabs were 20.0 - 25.0, 40.0 - 50.0 and 25.0 - 40.0 %, respectively. These finding should assist in the future establishment of a selective breeding program that produces the 1st genetically improved strain of P. pelagicus possessing desired traits such as fast growth and high survival rates.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Currently, the culture techniques for blue swimming crab (Portunus pelagicus) have not yet been fully established to expand the farms and increase productivity to a commercial scale&#x0D; It is generally accepted that using domesticated broodstock is advantageous due to their adaptation to a captive environment&#x0D; Successful aquaculture of P.pelagicus should rely on domesticated broodstock in which domestication improves reproductive and growth performances&#x0D; &#x0D; GRAPHICAL ABSTRACT

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.

The Quality of Eggs Derived from Japanese Quail Fed with the Fermented and Non-Fermented Rapeseed Meal.

The most popular protein source in poultry feed mixtures is soybean. However, cheaper and more available alternative protein sources are being sought, and feed manufacturers more and more often turn their attention to the post-extraction meals of local oil plants, e.g., rapeseed. Therefore, the effect of fermented and non-fermented post-extraction rapeseed meal used as a feed additive for Japanese quails was investigated on the eggs’ quality. The study was performed on 280 females of Japanese quails fed with a mixture without rapeseed meal, with non-fermented post-extraction rapeseed meal (5%, 10% and 15%) and with fermented one (5%, 10% and 15%). During the experiment, eggs were collected from each group four times (every 4 weeks) and evaluated for their quality characteristics. The addition of 10% fermented rapeseed meal had the most beneficial effect on such eggs quality traits as egg weight, specific gravity, yolk index and color and albumen pH. However, in the majority of examined parameters, no significant differences were found between birds fed with soybean meal and those fed with fermented and non-fermented rapeseed meal (morphological elements proportions, yolk weight, albumen height and Haugh’s units, eggshell quality). This supports the thesis that the use of rapeseed meals instead of soybean meals may allow obtaining the proper quality of animal raw materials at a lower cost and with the use of local feed resources.

Karakteristik Kimia Dan Fisik Telur Burung Gosong Filipina (Megapodius cumingii) Dari Pulau Toroguso, Kabupaten Banggai, Sulawesi Tengah, Indonesia

This research was conducted to examine the physical characteristics, chemical composition of the eggs of the filipina gosong bird (Megapodius cumingii) obtained from nesting sites on the coast of Poat Island, Pagimana District, Banggai Regency, Central Sulawesi Province. Measurement of the physical characteristics of eggs (weight, diameter, length and egg index) were carried out at the Laboratory of Biology Study Program, Tadulako University. Besides, observation on egg color, shape and egg texture were also conducted. Measurements of water and fat content, protein, carbohydrates, ash, crude fiber and egg antioxidants (Proxymate analysis) were carried out at the Chemistry Laboratory, Faculty of Mathematics and Natural Sciences, Tadulako University. Amino acid analysis was carried out at the Integrated Laboratory of IPB by using HPLC (High Performance Liquid Chromatography). The results showed that the eggs of the Filipina charred bird had an oval shape with two shell colors, dark brown and light brown, and the texture was smooth. The average size of egg weight, length, diameter and egg index were 99.35 g, 7.31 cm, 5.5 cm and 72.43%, respectively. The results of the chemical analysis of filipino gosong eggs revealed that water and fat content, protein, carbohydrates, ash, crude fiber and egg antioxidants were 50.45%, 18.75%, 13.40%, 0.02%, 375.98% and 1.82% respectively. The result showed a higher protein content compared to fat content. The 17 types of amino acids included essential and non-essential amino acids. Glutamate was the highest concentration of 2.10%, while cysteine was the lowest concentration of 0.15%.

Xylanase Supplementation in Wheat-Based Diets of Laying Hens Affects the Egg Yolk Color, Carotenoid and Fatty Acid Profiles.

Wheat is rich in non-starch polysaccharides (NSP) and their degradation in poultry diets is promoted by exogenous carbohydrases. The objective here was to evaluate the effect of adding an intrinsically thermostable xylanase on wheat-based diets for laying hens in yolk color, carotenoid and fatty acid profiles of eggs. A total of 128 laying hens were used for 12 weeks. They were randomly allocated to four dietary treatments with different levels of xylanase: T1: control (no xylanase), T2: 30,000 U/g, T3: 45,000 U/g and T4: 90,000 U/g, with 32 birds, 16 replicates per treatment (2 birds/replicate). At the end of the experimental period, egg yolk color index, redness (a*) and yellowness (b*) of egg yolks were found significantly higher in all the enzyme supplemented diet groups (T2, T3, T4) compared with the control (T1). Canthaxanthin levels were significantly higher in T3 than T1 (p < 0.05). Total n-3, n-6 and total polyunsaturated fatty acids (FAs) were significantly higher in T4 compared with the control (p < 0.01), while the reverse trend was evidenced for monounsaturated FAs. Additionally, total n-3 FAs were higher in the T2 than T1 (p < 0.005). Overall, the results showed that exogenous xylanase enzyme supplementation in wheat-based diets for laying hens contribute to maintaining egg yolk color. Overall, exogenous xylanase enzyme supplemented at all levels in wheat-based laying hens’ diets improved egg yolk color compared to the control diet. The enzyme supplemented at the higher level (90,000 U/g) improved polyunsaturated and reduced monounsaturated egg yolk fatty acid content.

How Egg Storage Duration Prior to Incubation Impairs Egg Quality and Chicken Embryonic Development: Contribution of Imaging Technologies.

Storing fertilised eggs prior to incubation is a frequent practice in commercial hatcheries to coordinate activities and synchronise hatchings. However, the conditions used to store eggs can have major impacts on egg quality and the subsequent viability of chicken embryos. While storage temperatures of 16–18°C are classically used in hatcheries, the duration of storage varies from three to more than 10 days. We explored the effect of storage duration (zero, three or 10 days; D0, D3 and D10, respectively) at 16°C, 80% relative humidity (RH) on egg quality (Broiler, Ross 308), using computed tomography (CT) and classical measurements (egg weight, eggshell strength, egg white pH, Haugh units, yolk index and colour). The results revealed that a storage duration of up to 10 days negatively affected some egg quality traits (yolk index and volume, air chamber volume and egg white pH). Eggs stored for three or 10 days were further incubated for 11, 13 or 15 days (37.8°C, 55% RH). Eggs were analysed by magnetic resonance imaging (MRI) and CT to assess the development of the embryo and internal egg changes occurring during incubation. First, data showed that the fertility and sex ratio of eggs were not affected by storage duration. However, the mortality of viable eggs was increased in the D10 group compared to the D3 group. Results of non-invasive imaging technologies revealed that the storage of eggs for 10 days impaired embryo growth as early as 11 days of incubation (decrease in brain and embryo volumes). Collectively, these data provide new evidence that the duration of egg storage negatively affects embryonic growth. They further corroborate that this parameter is likely to be crucial to synchronising embryonic stages and maybe reducing the hatching window, hence limiting the time spent by newborn chicks in hatchers. In addition, our results highlight that CT and MRI imaging technologies are useful non-invasive tools to evaluate egg quality prior to incubation and the impact of storage (or incubation) practices on developmental growth of the embryo.

Nest density, egg conspicuity, vegetation structure and seasonality affect artificial nest predation in the Brazilian Cerrado

AbstractNest predators use visual, acoustic and chemical cues to locate nests. In the Neotropics, predation is high being the main cause of nest failure. Despite that, it is still not completely clear what kind of information predators are using to find nests or whether predators respond differently according to habitat characteristics. Here, we executed an experimental manipulation to investigate how different ecological factors influence nest predation probability. We hypothesised that egg conspicuousness, nest clustering and a more open vegetation structure would increase nest predation probability, and that nest predation would be higher during the breeding season of most avian species in the region. We used artificial nests baited with plasticine and quail eggs (Coturnix coturnix), manipulated egg coloration and nest density. Artificial nests were distributed over forest and savanna-like vegetations. Overall predation rate was 40.9%. We found that nests baited with conspicuous eggs, located in open habitats, at higher densities and during the dry period were more predated. Results suggest that main predators must be visually orientated, and that egg crypsis is an important trait for open-nest species in the area. Moreover, a higher nest density may affect predator behaviour, favouring an increase in nest searching, which may be facilitated in open habitats.

The effects of canthaxanthin microencapsulation on yolk color and canthaxanthin deposition in egg yolk of laying hens

Canthaxanthin is widely used as a feed additive to improve skin and yolk color in poultry. It is insoluble in water and sensitive to oxidation, so commercial canthaxanthin is often microencapsulated with wall materials to improve its solubility and stability. The objective of this study was to evaluate the effects of canthaxanthin microencapsulation on yolk color and canthaxanthin deposition in egg yolk of laying hens. A total of 288 Hyline Brown laying hens (48 wk of age) were allocated to 4 groups with 6 replicates of 12 hens each, and fed a basal diet or the basal diet supplemented with 5 mg/kg canthaxanthin microencapsulated with modified starch (CMMS), gelatin (CMG), and sodium lignosulfonate (CMSL), respectively. Canthaxanthin supplementation did not affect laying performance of hens, but improved (P < 0.05) yolk color of fresh, fried, boiled, and stored (4 and 25°C) eggs. The improvement of yolk color of fresh eggs was greatest in the CMSL group and least in the CMG group (P < 0.05). Both CMMS and CMSL resulted in higher (P < 0.05) yolk canthaxanthin concentration than CMG. The CMSL resulted in higher (P < 0.05) yolk color score of fried eggs than CMMS and CMG and higher (P < 0.05) yolk color score of boiled eggs than CMG, but no difference was observed in stored eggs among three canthaxanthin groups. In conclusion, CMMS and CMSL were more effective in yolk pigmentation than CMG, and CMSL was slightly better than CMMS.