Chapter 4. Egg Size and Egg Quality

Few studies have demonstrated plasticity of egg size within the confines of an egg size–number trade-off in response to trophic conditions in fishes. Moreover, the physiological mechanisms that govern this plasticity are not known. Growth differentiation factor 9 (Gdf9) and bone morphogenetic factor 15 (Bmp15) are oocyte-specific factors implicated in follicular growth and ovulation in mammals. In order to investigate whether expression levels of these genes were correlated with ration-dependent changes in fecundity in fish, zebrafish (Danio rerio) were subjected to four different feeding regimens. Counts of spawned eggs or vitellogenic follicles were used to estimate fecundity, whereas quantitative polymerase chain reaction analyses were performed to determine Gdf9 and Bmp15 mRNA levels in response to changes in ration size. Both relative fecundity and gonadosomatic index increased significantly with increased ration size, whereas egg size and hatching rate decreased significantly. No significant differences in Gdf9 or Bmp15 transcript abundance were evident between feeding regimens, suggesting that these growth factors do not govern fecundity in fish. However, favourable trophic conditions markedly affected follicle or egg size and number, with important implications for downstream egg quality and survival.

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INTRASPECIFIC VARIATION IN THE GROWTH RATE OF GASTROPODS: FIVE HYPOTHESES

Memoirs of the Entomological Society of Canada ◽

10.4039/entm120146199-1 ◽

1988 ◽

Vol 120 (S146) ◽

pp. 199-213 ◽

Cited By ~ 12

Author(s):

Diane M. Shibata ◽

C. David Rollo

Keyword(s):

Growth Rate ◽

Egg Size ◽

Egg Quality ◽

Full Range ◽

Maternal Influence ◽

Causal Mechanism ◽

Intraspecific Interaction ◽

Enormous Variation ◽

High Degree ◽

Possible Cause

AbstractGastropods commonly show enormous variation in growth rate, even among identically reared siblings. This was investigated using a small isolated population of Deroceras laeve (Müller) — a species with low genetic variability. A high degree of variation in growth rate was evident, even among offspring from unmated mothers. This confirmed our hypothesis that this variation does not require high genetic polymorphism. Four additional hypotheses concerning the causal mechanism(s) for this variation were investigated: (1) Maternal influence through variation of egg quality was rejected as a possible cause for the variation since animals from mothers raised on either high- or low-quality diets did not differ significantly in growth or maturation rates (when egg size was controlled). (2) The possibility that animals might have their growth trajectory fixed by early nutritional experience was tested by initially rearing slugs on either high- or low-quality diets, and then reversing their food. Such "nutritional imprinting" was not supported. (3) Intraspecific interaction among individuals was not supported as a cause of variation either since stunted slugs did not show improved growth when isolated from conspecifics, and there was equal variation among individuals reared from the egg in isolation. (4) Variation in the egg size was the only characteristic investigated that significantly changed rates of juvenile growth and the timing of maturation. Larger eggs produced slower-growing slugs that matured later, and egg size seemed to account for the full range of observed variation. The ultimate function of the mechanism remains to be determined, but possibilities include adjusting the performance of offspring to resource supply, ensuring availability of mature individuals to breed during favourable microclimates, reducing competition among members of a cohort, or ensuring sexual heterogeneity for hermaphroditic breeding.

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Egg size, contents, and quality: maternal-age and -size effects on house fly eggs

Canadian Journal of Zoology ◽

10.1139/z00-086 ◽

2000 ◽

Vol 78 (9) ◽

pp. 1544-1551 ◽

Cited By ~ 35

Author(s):

G S McIntyre ◽

R H Gooding

Keyword(s):

Clutch Size ◽

Size Effects ◽

Maternal Age ◽

Egg Size ◽

Egg Quality ◽

Size Variation ◽

House Fly ◽

Egg Volume ◽

Hatch Rate ◽

Maternal Size

Egg size is generally regarded as a good predictor of egg quality. However, in phenotypic studies it is difficult to separate the effects of egg-size variation from the effects of the underlying cause of the differences in egg size. We examined the relationships between the size, shape, hatch rate, and biochemical and energy contents of house fly (Musca domestica L.) eggs using two distinct sources of egg-size variation: maternal age and maternal size. By comparing relationships among egg parameters between manipulations we were able to distinguish some maternal effects from pure egg-size effects. Maternal age was negatively correlated with clutch size, egg volume, hatch rate, and lipid content, but was not correlated with protein, carbohydrate, or energy content. Female size did not affect hatch rate or biochemical and energy contents, but was positively correlated with clutch size and egg volume. Partial correlation analyses revealed that egg-size variation due to maternal-age effects was unrelated to hatch rate, but that egg-size variation due to maternal-size effects was weakly negatively correlated with hatch rate. The results suggest that large and small house fly eggs differ primarily in size and that within size classes there is significant variation in other egg parameters. Size is not a useful predictor of egg quality in this system.

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Biochemical changes throughout early- and middle-stage of embryogenesis in lobsters (Homarus americanus) under varying thermal regimes

10.7287/peerj.preprints.26741 ◽

2018 ◽

Author(s):

Jason S Goldstein ◽

Winsor H Watson

Keyword(s):

Egg Size ◽

Egg Quality ◽

Marked Decrease ◽

Homarus Americanus ◽

Seasonal Temperature ◽

Time Intervals ◽

Biochemical Processes ◽

Thermal Regimes ◽

Marine Crustacean ◽

Full Complement

Most marine crustacean eggs contain a full complement of nutritional resources that fuel the growth and metabolic processes over the course of their development. In terms of biochemical constituents, lipids and proteins play pivotal and central roles in these processes and, accordingly, have been studied extensively in crustaceans. Given the propensity of some ovigerous (egg-bearing) American lobsters (Homarus americanus) to undergo seasonal inshore-to-offshore migrations, thereby exposing their eggs to varying thermal regimes, this study’s goal was to assess egg quality over their course of development by documenting changes in total lipids, proteins, and egg size (volume) in lobsters subjected to one of three simulated thermal regimes (inshore, offshore, constant (12°C), N = 5/trt, 15 total) in the laboratory and sampled at five discrete time intervals. Total egg lipids showed a marked decrease over time (r2adj = 0.85, P < 0.0001), early in the fall (average = -26%) and late spring (-62%), compared with stark increases in proteins over the same period (r2adj = 0.63, P < 0.0001, averages = 60%, 34%, fall and spring). Although there were no significant differences in total lipid or protein values (or egg sizes) between eggs exposed to inshore and offshore temperatures (P > 0.05), differences occurred in eggs exposed to a constant temperature, and they hatched almost three months sooner than inshore or offshore ones. Seasonal temperature fluctuations also appear to control the rates of biochemical processes in lobster eggs but may be confounded by other variables.

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Egg Size and Egg Quality

Physiological Adaptations for Breeding in Birds ◽

10.23943/princeton/9780691139821.003.0004 ◽

2012 ◽

Author(s):

Tony D. Williams

Keyword(s):

Life History ◽

Egg Size ◽

Egg Quality ◽

Life History Trait ◽

Egg Mass ◽

Optimum Size ◽

High Quality ◽

Mate Quality ◽

Good Proxy ◽

Egg Components

This chapter deals with variations in egg size and egg quality. Egg size is a highly variable life-history trait, with up to twofold differences in egg mass among individual females within a population. Larger eggs contain absolutely more major egg components (shell, albumen, yolk) and absolutely more of several minor egg components (maternally derived antibodies and antioxidants), and, in this regard, egg size is a good proxy for egg quality. Many studies assume that high-quality females produce large, high-quality eggs, but it is equally plausible that individual females produce eggs of the optimum size and quality for their phenotype or genotype. Either way, the aspects of a female's phenotype that would determine maximum or optimum egg size are unknown, although these are not primarily factors such as age, experience, body condition, or mate quality that continue to be the focus of much current work.

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Performance of laying hens fed on practical diets containing different levels of supplemental biotin during the rearing and laying stages

British Journal Of Nutrition ◽

10.1079/bjn19800022 ◽

1980 ◽

Vol 44 (2) ◽

pp. 151-159 ◽

Cited By ~ 9

Author(s):

C. C. Whitehead

Keyword(s):

Egg Size ◽

Laying Hens ◽

Egg Quality ◽

Egg Yolk ◽

Egg Laying ◽

Apparent Effect ◽

Laying Performance ◽

Egg Number ◽

Biotin Supplementation ◽

Different Levels

1. The effect of biotin supplementation of low-biotin practical diets during rearing and laying stages on performance was studied in White Leghorn-type laying hens.2. Biotin supplementation during rearing did not have any apparent effect on the condition of the bird at point-of-lay or on subsequent laying performance.3. Biotin supplementation during lay did not have any beneficial effect upon egg number, egg size or food intake or food conversion efficiency.4. Internal egg quality, as reflected by albumen height, was slightly improved by biotin supplementation of layer's diet.5. Input-output relationships were calculated for the incorporation of biotin in egg yolk.6. Metabolic measurements suggested that biotin concentration in egg yolk was the best criterion of biotin status in the hen.7. It is concluded that practical diets contain sufficient biotin to support optimum egg-laying performance in hens.

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INTERACTIVE EFFECTS OF SIZE, STORAGE METHOD AND DURATION ON QUALITY AND PHYSICAL CHARACTERISTICS OF TABLE EGGS

Nigerian Journal of Animal Production ◽

10.51791/njap.v23i1.2173 ◽

2021 ◽

Vol 23 (1) ◽

pp. 76-81

Author(s):

S. O. KEMBI ◽

A. A. OSOKOMAIYA

Keyword(s):

Specific Gravity ◽

Egg Size ◽

Room Temperature ◽

Egg Quality ◽

Interactive Effects ◽

Quality Changes ◽

Quality Indices ◽

Storage Method ◽

Weight Losses ◽

Long Storage

A total of 252 fresh table eggs sorted into standard, large and extra-large sizes were but.either refrigerated or held at room temperature and used to study their weekly weight losses (WL), specific gravity (SG), egg index (EI), yolk index (YI) and albumen height (AH) over a six week period. The results showed that among room-stored eggs there were declines (P<0.01) AH, YI, SG and El but an increase in WL with increased egg size. Similar trends in response to long storage were observed except that EI not affected (P>0.05). The depressive influences of long storage and larger sizes on egg quality observed in the room stored eggs diminished with refrigeration. The general patterns of quality deterioration show that, irrespective of egg size, six-week refrigerated eggs had better quality indices than one-week room-stored eggs. There was no significant (P>0.05) influence of egg size on quality changes during storage Based on the result it was included that in the absence of refrigeration and when eggs are sold in assorted sizes, table eggs should be consumed within 2 weeks of lay and larger eggs should be used first.

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Ostrich (Struthio camelus ) Egg Embryonic Death During Artificial Incubation

International Journal of Applied Sciences and Biotechnology ◽

10.3126/ijasbt.v3i4.13523 ◽

2015 ◽

Vol 3 (4) ◽

pp. 566-578

Author(s):

Aisha E. Faki ◽

E.A.E. Obeid ◽

Hagir I.M. Osman ◽

A.E Amin

Keyword(s):

Egg Size ◽

Microbial Contamination ◽

Egg Quality ◽

Storage Conditions ◽

Struthio Camelus ◽

Shell Quality ◽

Egg Hatchability ◽

Embryonic Death ◽

Artificial Incubation ◽

Ostrich Farming

Intensification of ostrich farming revealed that egg hatchability was remarkably lower than the wild. This review considers the factors leading to, as pertaining to the ostrich, egg and incubator. Ostrich genotype, age, season and congenital problems affect clutch and egg sizes and egg quality- fertility to lead a successful hatch. Egg treatment prior incubation can later reduce hatchability, affected by storage conditions and duration. Most detrimental factors lie in the incubator and hatcher management. Egg correct positioning and turning in the appropriate incubator humidity and temperature are likely to yield high hatch. Variability in egg size, shell quality, pore sizes and numbers govern the water loss and exchange of gases. The hatcher management is important when chicks need intervention. Dead-in-shell embryos, early or late were likely to be affected by all of the above factors plus egg microbial contamination or be merely nutritional.Int J Appl Sci Biotechnol, Vol 3(4): 566-578

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Egg size and lipid content of lake trout (Salvelinus namaycush) in the wild and in captivity

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2017-0408 ◽

2018 ◽

Vol 75 (12) ◽

pp. 2123-2135 ◽

Cited By ~ 1

Author(s):

Thomas A. Johnston

Keyword(s):

Lipid Content ◽

Egg Size ◽

Lake Trout ◽

Egg Quality ◽

Salvelinus Namaycush ◽

Ecosystem Size ◽

Captive Populations ◽

In The Wild ◽

Source Populations ◽

Quality Variation

Egg quality influences early life survival in fishes, but drivers of egg quality variation remain poorly understood. I examined egg quality of a long-lived, iteroparous salmonid (lake trout (Salvelinus namaycush)) with respect to maternal traits and environmental conditions in wild and captively reared populations. Variation was stronger and more consistent for egg size than for lipid content. Among females, egg size was most strongly related to maternal age, in both wild and captive populations, and faster-growing females tended to produce larger eggs. Among wild populations, maternal growth was more strongly associated with indices of ecosystem size or productivity than climate, whereas the opposite was observed for egg size. Egg size and, to a lesser extent, maternal growth in captive populations were positively correlated with egg size and growth, respectively, in their wild source populations. However, captive females grew faster and produced larger eggs at age, but smaller eggs at length, than their wild counterparts. Lake trout egg quality variation has both maternal and environmental components, and captive rearing appears to alter the ontogenetic progression of egg size.

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