Egg and math: introducing a universal formula for egg shape Narushin, Valeriy G.; Romanov, Michael N.; Griffin, Darren K.
Annals of the New York Academy of Sciences,
December 2021, 2021-12-00, 20211201, Letnik:
1505, Številka:
1
Journal Article
Recenzirano
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The egg, as
one of the most traditional food products, has long attracted the attention of mathematicians, engineers, and biologists from an analytical point of view. As a main parameter in ...oomorphology, the shape of a bird's egg has, to date, escaped a universally applicable mathematical formulation. Analysis of all egg shapes can be done using four geometric figures: sphere, ellipsoid, ovoid, and pyriform (conical or pear‐shaped). The first three have a clear mathematical definition, each derived from the expression of the previous, but a formula for the pyriform profile has yet to be derived. To rectify this, we introduce an additional function into the ovoid formula. The subsequent mathematical model fits a completely novel geometric shape that can be characterized as the last stage in the evolution of the sphere—ellipsoid—Hügelschäffer's ovoid transformation, and it is applicable to any egg geometry. The required measurements are the egg length, maximum breadth, and diameter at the terminus from the pointed end. This mathematical analysis and description represents the sought‐for universal formula and is a significant step in understanding not only the egg shape itself, but also how and why it evolved, thus making widespread biological and technological applications theoretically possible.
The shape of a bird's egg has escaped a universally applicable mathematical formulation. All egg shapes can be described as one of four geometric figures: sphere, ellipsoid, ovoid, and pyriform (conical or pear‐shaped). The first three have a clear mathematical definition, but a formula for the pyriform profile has yet to be derived. We postulate here a theoretical formula that is a universal equation solution for determining egg contours, including the pyriform.
Wulong geese (Anser cygnoides orientalis) are known for their excellent egg-laying performance. However, they show considerable population differences in egg-laying behavior. This study combined ...genome-wide selection signal analysis with transcriptome analysis (RNA-seq) to identify the genes related to high egg production in Wulong geese. A total of 132 selected genomic regions were screened using genome-wide selection signal analysis, and 130 genes related to high egg production were annotated in these regions. These selected genes were enriched in pathways related to egg production, including oocyte meiosis, the estrogen signaling pathway, the oxytocin signaling pathway, and progesterone-mediated oocyte maturation. Furthermore, a total of 890 differentially expressed genes (DEGs), including 340 up-regulated and 550 down-regulated genes, were identified by RNA-seq. Two genes -- GCG and FAP -- were common to the list of selected genes and DEGs. A non-synonymous single nucleotide polymorphism was identified in an exon of FAP. Based on genome-wide selection signal analysis and transcriptome data, GCG and FAP were identified as candidate genes associated with high egg production in Wulong geese. These findings could promote the breeding of Wulong geese with high egg production abilities and provide a theoretical basis for exploring the mechanisms of reproductive regulation in poultry.
A 35-day experiment was conducted to evaluate the effect of selenium-enriched probiotics (SP) on laying performance, egg quality, egg selenium (Se) content, and egg glutathione peroxidase (GPX) ...activity. Five hundred 58-week-old Rohman laying hens were randomly allotted to 5 dietary treatments of 100 each. Each treatment had 5 replicates, and each replicate had 5 cages with 4 hens per cage. The SP was supplemented to a corn-soybean-meal basal diet at 3 different levels that supplied total Se at 0.2, 0.5, and 1.0 mg/kg. The basal diet served as a blank control, while the basal diet with supplemental probiotics served as a probiotics control. The results showed that dietary SP supplementation not only increased (p < 0.05) the rate of egg laying, day egg weight, mean egg weight, egg Se content, and egg GPX activity but also decreased (p < 0.05) the feed:egg ratio and egg cholesterol content. The egg Se content was gradually increased (p < 0.05) along with the increasing level of dietary Se. The SP supplementation also slowed down (p < 0.05) the drop of Haugh units (HU) of eggs stored at room temperature. The egg GPX activity had a positive correlation (p < 0.01) with egg Se content and a negative correlation (p < 0.01) with egg HU drop. These results suggested that Se contents, GPX activity, and HU of eggs were affected by the dietary Se level, whereas the egg-laying performance and egg cholesterol content were affected by the dietary probiotics. It was concluded that this SP is an effective feed additive that combines the organic Se benefit for hen and human health with the probiotics benefit for laying hen production performance. It was also suggested that the eggs from hens fed this SP can serve as a nutraceutical food with high Se and low cholesterol contents for both healthy people and patients with hyperlipidemia, fatty liver, or cardiovascular disease.
The effectiveness of various coatings (whey protein isolate WPI, whey protein concentrate WPC, zein, and shellac) on functional properties, interior quality, and eggshell breaking strength of fresh ...eggs were evaluated during storage at 24°C for 6 weeks. Coatings and storage time had significant effects on Haugh unit, yolk index, albumen pH, dry matter (DMA), relative whipping capacity (RWC), and albumen viscosity. Uncoated eggs had higher albumen pH (9.56) and weight loss, and lower albumen viscosity (5.73), Haugh unit (HU), and yolk index (YI) during storage. Among the coated eggs, the shellac and zein coated eggs had the highest value of albumen viscosity (27.26 to 26.90), HU (74.10 to 73.61), and YI (44.84 to 44.63) after storage. Shellac (1.44%) was more effective in preventing weight loss than WPC (4.59%), WPI (4.60%), and zein (2.13%) coatings. Uncoated eggs had the higest value (6.71%) of weight lost. All coatings increased shell strength (5.18 to 5.73 for top and 3.58 to 4.71 for bottom) significantly (P < 0.05) compared to the uncoated eggs (4.70 for top and 3.15 for bottom). The functional properties such as albumen DMA (14.50 to 16.66 and 18.97 for uncoated) and albumen RWC (841 to 891 and 475 for uncoated) of fresh eggs can be preserved during storage when they are coated. The shellac and zein coatings were more effective for maintaining the internal quality of fresh eggs during storage. Fourier transform near infrared (FT-NIR) in the 800 to 2500 nm reflection spectra were used to quantify the contents of the fresh eggs at the end of storage. Eggs coated with shellac or zein displayed a higher absorbance at 970 and 1,197 nm respectively (OH vibration of water) compared with those coated with WPI or WPC and the uncoated group at the end of storage. The coatings improved functional properties and also shell strength and could be a viable alternative technology for maintaining the internal quality of eggs during long-term storage. This study highlights the promising use of various coatings to both enhance the functional properties and to reduce the breakage of eggs.
This experiment was conducted to study the prevalence of
Salmonella and
Escherichia coli (
E.
coli). from the surface of egg shells, egg shell membranes or pores, and internal contents from unwashed ...eggs collected from commercial caged layer farms in Australia. Egg shell swabs, shell crush and egg internal contents (yolk and albumen) of an individual egg were processed for bacteriological examination.
Salmonella spp. were not detected from any of the egg shell surfaces, egg shell crush or egg internal contents. Thirty five
E. coli isolates were isolated from the egg shell surface. Ten
E. coli strains were also isolated from shell crush. However, the internal contents of eggs appeared to be sterile. Polymerase chain reaction was performed on forty-five
E.
coli isolates using primers for heat stable enterotoxin genes A and B (
STa and
STb) and also for colicin V gene (
cvaC).
STa gene was detected in four
E.
coli isolates isolated from egg shell surfaces. All the
E.
coli isolates were negative for
STb and
cvaC genes. These data provide useful information regarding the prevalence of virulent
E.
coli and
Salmonella spp. on and in unwashed eggs collected from layer farms. These data also suggest that unwashed eggs collected from caged layer farms are unlikely to be sources of
Salmonella outbreaks. Egg shell translucency could be due to changes in the mammillary layer and mamillary cores during the early phases of egg shell formation and has the potential to increase the incidence of microcracks in egg shells, and hence, may be responsible for bacterial penetration. There was a significant correlation between egg shell translucency and egg shell penetration by
Salmonella Infantis and
E coli. Both strains of bacteria were able to penetrate the translucent egg shells even at very low doses. The penetration, however, was hindered in both translucent and non translucent eggs at 4
°C, as compared with room temperature which highlights the importance of storage of eggs at refrigerated temperatures.
Eggs in our life Hunton, Peter
World's poultry science journal,
06/2013, Letnik:
69, Številka:
2
Journal Article
Recenzirano
Omega fatty acid, vitamin and mineral content of eggs in relation to human nutritional needs are discussed in detail and the potential to modify these in special eggs is covered.
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