Freshly-laid Eggs Research Articles

Effects of replacement noug seed cake (Guizotia abyssinica) with treated tagasaste (Chamaecytisus palmensis) leaf meal on egg quality traits of layer hens

Egg quality treats are significantly impacted by nutritional factors either deficient or excessive quantities in the layer diets. In this study one hundred eight, 32 weeks age of Bovans Brown chickens were used as an experimental animals. Four iso-nitrogenous and iso-caloric based ration diets were formulated. The level of ration replacing NSC by TTLM was at 0%(T1), 5%(T2), 10%(T3) and 15%(T4) from the total ration. Complete Randomized Design (CRD) was used with four treatments, three replicate (9chicken/replicate) and the experiment lasted for 12 weeks. Egg quality parameters were determined at the interval 28 days by randomly taking 5 freshly-laid eggs from each replication and determine egg size, eggshell, albumen and yolk quality by using different measurement parameters. The results showed that egg shape index, yolk weight (g) and yolk ratio (%) were similar (P>0.05) among treatment groups. Eggshell thickness and yolk color score were significantly varied (p<0.05) with different levels of TTLM substitution. In the present study shell thickness, shell weight and shell ratio were higher in the treatment groups (5, 10 and 15% TTLM) than the control (0%) diets. The study showed that shell thickness ranged from 0.32-0.38 mm at T1 and T3 TTLM, respectively. Haugh unit (84.04±1.79) and albumen height (7.01±0.23) were highest (P<0.05) at T3 than the other treatments. Based on results most of the external and internal egg quality parameters were significantly changed when the level of TTLM increased up to15% than the control diet and it implies a great opportunity in utilizing TTLM.

Elastic Moduli of Avian Eggshell.

Simple SummaryBirds have existed on Earth for over one hundred million years, and the eggshell is one of the main factors in them having survived for such a long period of time. The avian eggshell is a multifunctional thin-shelled structure that protects the developing embryo from damage and excessive water loss, provides the embryo with calcium for its skeleton, and sustains the weight of incubating birds. It must also be breakable for the hatchling to emerge. Elastic modulus (Young’s modulus) is the most fundamental mechanical property for such a load-bearing structure. Despite extensive studies on avian eggs, our understanding of the elastic moduli and structure–function relationship of avian eggshells remains incomplete—most previous works have focused on chicken or only a few species. One challenge is the availability and collection of freshly-laid egg samples. The present study is based on 700 freshly-laid eggs collected over a period of seven years from 2015 to 2021, covering a wide taxonomic scale and egg mass (from 1 g to 1459 g). With this large dataset, we may obtain a bird’s-eye view of the elasticity and structure–function relationships of the avian eggshell.We analyze 700 freshly-laid eggs from 58 species (22 families and 13 orders) across three orders of magnitude in egg mass. We study the elastic moduli using three metrics: (i) effective Young’s modulus, EFEM, by a combined experimental and numerical method; (ii) elastic modulus, Enano, by nanoindentation, and (iii) theoretical Young’s modulus, Etheory. We measure the mineral content by acid-base titration, and crystallographic characteristics by electron backscatter diffraction (EBSD), on representative species. We find that the mineral content ranges between 83.1% (Zebra finch) and 96.5% (ostrich) and is positively correlated with EFEM—23.28 GPa (Zebra finch) and 47.76 GPa (ostrich). The EBSD shows that eggshell is anisotropic and non-homogeneous, and different species have different degrees of crystal orientation and texture. Ostrich eggshell exhibits strong texture in the thickness direction, whereas chicken eggshell has little. Such anisotropy and inhomogeneity are consistent with the nanoindentation tests. However, the crystal characteristics do not appear to correlate with EFEM, as EFEM represents an overall “average” elasticity of the entire shell. The experimental results are consistent with the theoretical prediction of linear elasticity. Our comprehensive investigation into the elastic moduli of avian eggshell over broad taxonomic scales provides a useful dataset for those who work on avian reproduction.

THE RELATIONSHIPS BETWEEN SELECTED EGG QUALITY TRAITS AND EGG SIZE

The relationships between selected egg quality traits and sizes of eggs were studied in a part of the South Western Nigeria with a view to egg marketers and to investigating the variation in egg quality egg size changes. 320 market eggs and 40 freshly-laid eggs collected from a poultry farm were used for the study in which egg weight, specific gravity, haugh units, percent yolk, percent albumen, shell thickness and percent shell measurements were obtained. Quality traits for small and large-sized eggs were observed as: Egg Weight (53.34 vs 67.07 g), shell thickness (0.375 mm Vs 0.377mm), Percent shell (9.60 Vs 8.94), specific gravity (1.073 1.069), haugh unit (67.65 Vs 61.38), Percent albumen (62.28 Vs 64.35) and percent yolk (28.13 Vs 26.71), respectively. Egg size was observed to correlate positively with percent albumen (P<0.05) and shell thickness. It, however, correlated negatively with all other quality traits measured. Regression models between eggsize and the various quality traits were also established. It was concluded that small-sized eggs could be of better quality in terms of the traits measured.

Effect of Hen Age, Storage Duration and Temperature on Egg Quality in Laying Hens

Eggs from two age flocks (40 and 60 wk old laying hens) in a commercial layer operation were sampled immediately after lay and used them for egg quality after periods of storage of 7, 14, 21 and 28 days at room temperature or in a refrigerator. Freshly-laid eggs from two age groups did not differ in egg weight, Haugh unit, albumen pH, albumen and yolk weights and eggshell thickness. Upon incubation at different temperature and duration of storage, age of hen did not affect egg weight loss or Haugh unit, but effected on yolk and albumen weights. Increase in storage temperature accelerated egg weight loss and reduction in albumen weight, but decreased Haugh unit and the pH of albumen. As the storage duration increased, egg weight loss, albumen pH and yolk weight were increased, but Haugh unit was lowered. Interaction between temperature and storage duration was noticed in egg weight loss, Haugh unit and albumen pH. Age of hens did not interact with either temperature or storage duration in egg quality parameters measured. It i s concluded that egg quality is more affected by temperature or storage duration, but not by hen age. As the age of hens is an important contributing factor to egg quality, further study is needed to clarify no clear effect of hen age on egg quality emerged from in this study.

계란의 유통 중 품질예측을 위한 품질지표 선정

This study was conducted to identify quality indicators of the freshness of chicken eggs circulating in domestic markets. We first stored freshly-laid eggs at temperatures of 0, 10, 20, and 30°C, investigated their weight-loss rate, specific gravity, color, york index, albumen index, Haugh unit (HU), pH, and sensory evaluation, and finally analyzed the correlation between each quality characteristic and the sensory preference. At all the storage temperatures, the quality characteristics of the weight-loss rate, specific gravity, yolk index, albumen index, and HU showed significant correlations (p<0.05) with the preference. In particular, the temperature-dependent correlation between the quality characteristics and the sensory preference was significantly higher with increasing storage temperatures and weight-loss rates (r = -0.78; r = -0.93; r = -0.95; and r = -0.99), albumen index (r = 0.66; r = 0.89; r = 0.89; and r = 0.93), and HU values (r = 0.64; r = 0.92; r = 0.96; and r = 0.98) at 0, 10, 20, and 30°C, respectively (p<0.01). The Color and pH examinations yielded disparate results, and further research is needed to determine the methods of using the characteristics as quality indicators. We believe that the changes in the weight-loss rate, specific gravity, yolk index, albumen index, and HU are adequate quality indicators of the freshness of egg in circulation.

Cues for communal egg-laying in lizards (Bassiana duperreyi, Scincidae)

Animals may aggregate either because the presence of conspecifics provides information about habitat suitability, or because the presence of conspecifics directly enhances individual viability. For a female lizard, the advantage of laying her eggs in a communal nest may entail either information transfer (hatched eggshells show that the site has been successful in previous seasons) or direct physiological benefits (recently-laid eggs can enhance water availability to other eggs). We tested the relative importance of these two mechanisms in the three-lined alpine skink (Bassiana duperreyi Gray, 1838) by offering gravid females a choice between sites with hatched eggshells versus freshly-laid eggs. Females selectively oviposited beside fresh eggs. In this species, early-nesting females use information transfer (i.e. the presence of old eggshells) as a nest-site criterion, whereas later nesters switch to a reliance on direct benefits of conspecific presence (i.e. the presence of freshly-laid eggs).

Penguin chicks benefit from elevated yolk androgen levels under sibling competition.

Crested penguins (genus Eudyptes) have a peculiar hatching pattern, with the first-laid egg (A-egg) hatching after the second-laid egg (B-egg) and chicks from A-eggs typically having a much lower survival probability. Maternal yolk androgens have been suggested to contribute to the competitive superiority of the B-chick in southern rockhopper penguins Eudyptes chrysocome, given their important role in mediating sibling competition in other species. We therefore increased the yolk androgen levels in freshly-laid eggs and examined the consequences for sibling competition - via effects on embryonic developmental times, chick growth and early survival. We placed one androgen-treated egg and one control egg into each foster nest, matching them for mass, laying date and laying order. The androgen treatment did not significantly affect embryonic developmental times or chick measurements at hatching. However, elevated yolk androgen levels benefitted chick growth in interaction with the number of siblings in a brood. Chicks from androgen-treated eggs had faster growth in the presence of a sibling than chicks from control eggs. Under these circumstances they also had a higher survival probability. Thus maternal androgens appear to reinforce the observed hatching pattern, facilitating brood reduction. This contrasts to most previous studies in other species where yolk androgens have been shown to compensate for the negative consequences of delayed hatching within the brood hierarchy.

Residual yolk energetics and postnatal shell growth in Smooth Softshell Turtles, Apalone mutica

We examined functions of residual yolk (RY 1 1 RY: residual yolk. ) in hatchling Smooth Softshell Turtles ( Apalone mutica). Removal of RY did not affect survival, shell growth, or resting metabolic rates of turtles for 40 d after hatching. Our estimates of metabolic rate suggest that RY can fuel maintenance and activity metabolism for approximately 25 days. A. mutica absorb more than 1 g of water in the first 2 weeks of life, which appears to be the basis of post-hatch shell expansion rather than yolk-provisioned growth. Post-hatch growth may be limited by the magnitude of RY remaining at hatching, but RY protein and lipid proportions do not differ from those of freshly-laid eggs. In addition, A. mutica did not use RY to fuel nest emergence. Our results suggest that RY does not fulfill several hypothetical functions in A. mutica, including postnatal growth, catabolic fuel for nest emergence, and long-term nutritional sustenance for maintenance, activity, or hibernation. Instead, A. mutica appear to absorb most yolk prior to hatching, and are left with a minimum of RY. Variation in RY mass with incubation regime in other species suggests that mothers may overprovision their eggs to ensure successful development across a diversity of possible incubation conditions.

Comparisons of egg incubation and hatchling traits among captive cohorts of the Chinese three-keeled pond turtle, Chinemys reevesii

Freshly-laid eggs of the Chinese three-keeled pond turtle ( Chinemys reevesii) from captive cohorts in Hunan, Shanghai and Jiangxi were incubated at four constant temperatures of 24, 26, 28 and 30 °C to assess the effects of incubation temperature and cohort origin on incubation duration and hatchling phenotypes. Eggs from the three cohorts differed in size and shape. Egg mass and width were greatest in the Hunan cohort, smallest in the Jiangxi cohort, with the Shanghai cohort in between. Incubation duration decreased with increasing temperature and differed among the cohorts, with longer incubation duration for eggs from the Jiangxi cohort than those from the Hunan or Shanghai cohorts. Incubation temperatures significantly affected hatchling size and hatchlings from 30 °C were smaller than those from the lower temperatures in terms of carapace size and body mass. When incubated at a common temperature, hatchlings from the Hunan and Shanghai cohorts were larger than those from the Jiangxi cohort. The swimming capacity of hatchlings was affected by incubation temperature, but did not differ among the cohorts. The characteristics of eggs and hatchlings were similar among the Hunan and Shanghai cohorts, but they differed significantly from the Jiangxi cohort.

Lipid composition and utilization in developing eggs of two tropical marine caridean shrimps (Decapoda: Caridea: Alpheidae, Palaemonidae)

Changes in biomass and lipid biochemistry during egg development were studied in the tropical shrimps, Alpheus saxidomus and Palaemonetes schmitti, from Pacific Costa Rica. Freshly-laid eggs of P. schmitti were substantially smaller than those of A. saxidomus; dry mass decreased during embryogenesis in the former species but remained almost constant in the latter one. Water content of eggs close to hatching were similar among both species (roughly 75%). Newly-produced eggs of the two species contained ≈20% fatty acids per egg dry mass; a comparison with data concerning decapods inhabiting tropical and temperate waters revealed that eggs produced by shrimps inhabiting tropical waters tend to have a higher lipid egg content per dry mass than those from temperate regions. Major lipid classes in the eggs of both species were phospholipids and triacylglycerols which increased and decreased during the incubation period, respectively. The predominant fatty acids of P. schmitti eggs were 16:0, 20:5(n-3) and 22:6(n-3) whereas eggs of A. saxidomus showed high amounts of 16:0, 20:5(n-3) and 16:1(n-7), and remarkably low values of 22:6(n-3) fatty acid. Lipid utilization was more pronounced in P. schmitti; in A. saxidomus, eggs close to hatching still contained 70% of the initially deposited fatty acid content which may indicate an enhanced independence of the newly-hatched larvae on external energy resources. The observed differences may partially be related to different habitat preferences, however, the role of adaptation and phylogeny as determinants of egg lipid biochemistry in caridean shrimps remains to be clarified.

Ropalidia rufoplagiata: a polistine wasp society probably lacking permanent reproductive division of labour

Ropalidia rufoplagiata Cameron (Hymenoptera: Vespidae), a polistine species from penisular India, appears to be unique among all known primitively eusocial wasps. A total of 33 out of 46 identified females from an observed colony were found to oviposit on 1-17 occasions. No single predominant egg-layer could be identified during the 45-day period. Of the 17 dissected egg-layers, 12 were mated. All egg-layers showed several oviposition-related behavioural patterns including systematic, but indiscriminate, cannibalism of eggs and larvae, cleaning of empty cells, and guarding of freshly-laid eggs. There was no correlation between the egg-laying activity of the females (whether mated or not), oophagy, and their position in the dominance hierarchy. All nest-maintenance activities were performed exclusively by the egg-layers, while the non-egg-layers were mainly involved in the extranidal task offoraging. No significant morphometric differences between egg-layers and foragers could be discerned. Almost all the older individuals in the colony were egg-layers, while foragers were mainly younger animals. Such a temporal differentiation in reproductive labour suggests the absence of a permanent reproductive caste in this species.

Distribution of Immunoglobulins During Embryogenesis in the Chicken*

Whereas the yolk of freshly-laid eggs contains only IgG, apart from traces of IgA, we were able to measure, on average, 0.145 mg/ml IgM and 0.207 mg/ml IgA in the yolk sac contents of 21-day-old chicken embryos. Up to the 14th embryonic day, IgG is exclusively contained in the yolk sac contents. It was not possible to demonstrate an increase in the amount of immunoglobulins present by comparing the amounts of IgM and IgA in freshly-laid eggs and in the yolk sac contents of 21-day-old embryos. The offspring of hens with experimentally-induced agammaglobulinemia did not begin with the production of the immunoglobulin isotypes IgG, IgM and IgA until after hatching. From these results the conclusion can be drawn that the immunoglobulins IgM and IgA are transferred from the egg white to the yolk sac contents during the last third of embryonic development. Embryonic synthesis of these immunoglobulins can be discounted as a result of this study. Synthesis was found to be initiated between the 2nd and 7th day of life for IgG, between the 2nd and 4th day of life for IgM and between the 6th and 13th day of life for IgA.

Alkylphosphonic acid distribution in the planorbid snail Helisoma sp.

1. 1. In the adult pulmonate snail Helisoma sp., ca 29% of the total phosphorus is present as alkylphosphonate, principally 2-aminoethylphosphonic acid (AEP), while in freshly-laid eggs, 98% is present as alkylphosphonate. 2. 2. 31P NMR analysis showed major differences in the phosphonate region of the spectrum of hot water extracts from eggs, compared to snails. 3. 3.Hot water extractable material from eggs had a mol. wt of greater than 1.5 × 10 6 by gel filtration and contained 2.5% AEP, 48% hexose and less than 1% amino acids. 4. 4.|AEP appears to be attached to the high mol. wt material by a phosphonomonoester bond.

Clutch size, intraclutch egg size variation, and breeding strategy in the GoldcrestRegulus regulus

In Fennoscandia the Goldcrest regularly lays two clutches per breeding season. Near Trondheim in Central Norway (about 63° N) the mean size of 11 first clutches was 10.4 (9–12) eggs and of 10 second/repeat clutches 9.4 (8–11) eggs. Mean egg length was 13.49 mm, breadth 10.35 mm, mean weight of freshly-laid eggs 0.78 g, volume 737 mm3 and shape index 130.6. The correlation coefficient for egg length against weight was 0.47, and for egg breadth against weight 0.77. For the four clutches studied in more detail, all egg dimensions, except the shape index, increased with the laying sequence. On average, the last-laid egg was 20.1 % heavier than the first-laid egg, or 5.6 % heavier than the mean weight for the whole clutch. The 3–5 last-laid eggs in the clutch deviated by about the same magnitude from the clutch mean. Because of the pronounced asynchrony in hatching, the size-hierarchy within a Goldcrest brood may be considerable, at least 1:5. The survival chances of the smallest young in a brood apparently depend mainly on the prevailing food supply. The primary advantage of hatching from a relatively large-sized egg is probably that such a hatchling is strong enough to secure itself a favourable feeding position in the crowded nest, in which the young often form 2–3 horizontal layers. The parental selection of food is adjusted to the size of the young, even in a brood with a marked size-hierarchy. It is concluded that the Goldcrest has evolved a brood reduction strategy.

Bacteria associated with four species of Dacus (Diptera: Tephritidae) and their role in the nutrition of the larvae.

The bacteria associated with Dacus tryoni (Froggatt), Dacus jarvisi (Tryon), Dacus neohumeralis (Hardy) and Dacus cacuminatus (Hering) were examined. Bacteria were isolated from the surface of freshly-laid eggs, from within surface sterilised pupae, from heads and abdomens of wild and laboratory-maintained flies, and from decomposed fruits in which the wild larvae were feeding. A more diverse flora was associated with D. tryoni and D. jarvisi (15 and 14 species, respectively) than with D. neohumeralis and D. cacuminatus (9 and 6 species, respectively). Most of the bacteria belonged to the family Enterobacteriaceae and while there were similarities of bacterial associations between fly species there was no evidence of a strict symbiotic association of a particular bacterium or bacteria with each species of fly. The larvae of D. jarvisi were unable to develop normally in an artificial medium containing unhydrolysed protein and free of bacteria and on a medium containing casein and Serratia liquefaciens (isolated from the flies and shown to secrete protease) the larvae died. On the same casein medium containing Enterobacter cloacae (isolated from the flies and shown to be protease negative) the larvae developed normally. Larvae of D. tryoni and D. jarvisi were devoid of protease and cellulase activity, but contained some amylase activity. The significance of these results in terms of current hypotheses concerning symbioses between tephritids and bacteria is discussed.

Calcium metabolism in embryos of the oviparous snake Coluber constrictor.

Total calcium in embryos of an oviparous, colubrid snake (Coluber constrictor L.) rises rapidly during the last half of incubation as the embryos increase in size. Although most of this calcium is drawn from stores in the yolk, hatchlings contain more calcium than was present in yolk of eggs at oviposition. Because shells from eggs incubated to hatching contain less calcium than do shells from freshly-laid eggs, the extra calcium appears to be drawn from the eggshell. Indeed, approximately 20% of the calcium required for development in this snake is obtained from the eggshell, with the remainder coming from the yolk. Thus, embryos of oviparous snakes, like embryonic chelonians, crocodilians and birds, withdraw calcium from their eggshells and do not rely exclusively on calcium supplied in their yolk for support of growth and development.

Some Factors Influencing Bacterial Penetration of Eggs

A SIGNIFICANT percentage of commercial eggs undergo marked deterioration in quality or even complete spoilage before reaching the consumer. The prevalent opinion is that microorganisms play a dominant role in this deterioration, a concept supported by the fact that parallel with or preceding deterioration there is frequently mass growth of bacteria in the egg.Views expressed in the literature relative to the influence of various factors upon the microbial content and growth in eggs are rather divergent. The available data are fairly consistent, however, in indicating that only a small proportion of freshly-laid eggs contains living organisms, and that in these, the number of bacteria is relatively low (Tanner, 1944). Furthermore, it has been observed repeatedly that eggs held or stored under a variety of environmental conditions exhibit extremely wide individual variation in the rate at which deterioration in quality takes place. This is true even when the environmental conditions would .