Avian eggshells are variedly coloured, yet only two pigments, biliverdin and protoporphyrin IX, are known to contribute to the dramatic diversity of their colours. By contrast, the contributions of structural or other chemical components of the eggshell are poorly understood. For example, unpigmented eggshells, which appear white to the human eye, vary in their ultraviolet (UV) reflectance, whi...

1. Environmental factors such as temperature, humidity and partial oxygen pressure can affect avian eggshell structure because gas exchange across the shell must allow sufficient water loss while preventing dehydration of the embryo. Studies of species with known chronology of colonization of novel environments provide a powerful insight into the relative importance of ecological factors shapin...

A 10 wk trial was conducted to investigate the effect of using ground, sterilized eggshell as a calcium source in the diet of laying hens. Egg production, egg and eggshell quality, hatching characteristics and eggshell ultrastructure were evaluated. A total of 144 hens aged 25 wk were housed in floor pens, located in a conventional open-sided layer shed. The birds were randomly divided into thr...

The current study was conducted to compare and contrast the uses of 2 devices (temperature transponder or infrared thermometer) and their locations (inner air cell membrane or outer eggshell surface) in Ross × Ross 708 broiler hatching eggs. The air cells of 14 embryonated and 10 nonembryonated eggs were implanted with temperature transponders on d 13.5 of incubation. Likewise, for these same e...

We compared eggshell thickness of hatched eggs with that of non-developed eggs in endangered falcon taxa to explore the effect of embryo development on eggshell thinning. To our knowledge, this has never been examined before in falcons, despite the fact that eggshell thinning due to pollutants and environmental contamination is often considered the most common cause of egg failure in falcons. B...

Cuttlefish eggs were exposed to background concentrations of dissolved Ag and Cd, using the radiotracers (110m)Ag and (109)Cd. At different time of the embryonic development (50 days), some eggs were placed in non-contaminating conditions. During the experiment, the uptake and depuration kinetics, and distribution of these metals among the egg compartments (i.e. eggshell, vitellus, peri-vitelli...

Objective. The objective of this study was to investigate changes in pigment, spectral transmission and element content of chicken eggshells with different intensities of pink pigment during the incubation period. We also investigated the effects of the region (small pole, equator and large pole) and pink pigment intensity of the chicken eggshell on the percent transmission of light passing thr...

STRNKOVÁ JANA, NEDOMOVÁ ŠÁRKA, KUMBÁR VOJTĚCH, TRNKA JAN. 2016. Tensile Strength of the Eggshell Membranes. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 64(1): 159–164. The mechanical behaviour of eggshell membranes under tensile loading has been studied. Samples from diff erent bird species (hen, goose and Japanese quail) have been used. Samples were cut out of the m...

One hundred and eighty 28-days-old Arbor Acres broiler birds were utilized in a 28 day experiment to investigate the effect of replacing bone ash with eggshell meal in the diet of broiler birds on their nutrient digestibility and blood parameters. Five experimental diets tagged T1, T2, T3, T4 and T5 were formulated to be isocaloric (2865.53 kcal ME/kg) and isonitrogenous (20% crude protein) suc...