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...

Birds' eggshells are renowned for their striking colours and varied patterns. Although often considered exceptionally diverse, we report that avian eggshell coloration, sampled here across the full phylogenetic diversity of birds, occupies only 0.08-0.10% of the avian perceivable colour space. The concentrations of the two known tetrapyrrole eggshell pigments (protoporphyrin and biliverdin) are...

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...

the present study was conducted to determine the effects of rice bran and dietary multi-enzyme (natuzyme) on performance, egg quality, and blood biochemical parameters of 288 laying hens during 12 week. this experiment was conducted in a completely randomized design in a factorial arrangement of 4×2, with four different levels of rice bran (0, 5, 10 and 15%) and two levels of multi enzyme (0 an...

The quality of eggs laid by 2 hybrid and 2 Italian dual-purpose genotypes of hens reared under organic farming system was studied. Hens belonging to Hy-Line Brown (brown eggshell, HLB), Hy-Line White (white eggshell, HLW), Ermellinata di Rovigo (brown eggshell, E), and Robusta maculata (brown eggshell, R) genotypes were reared from 24 to 43 wk of age. The trial was carried out from July to Dece...

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...

The objective of this experiment was to replace soya bean oil with glycerol in laying hen diets and assess the change's effect on performance, parameters of egg quality and the egg fatty acid profile. A total of 60 44-week-old Hy-Line W36 laying hens were distributed according to a completely randomised experimental design into four treatments consisting of glycerol substitutions for soya bean ...

The aim of this study was to evaluate different feeding schedules and their relationship to calcium (Ca) and phosphorus (P) plasma levels and egg quality of broiler breeders. The feeding schedules were: single feeding at 8:00 AM; twice daily feeding (50% at 8:00 AM and 50% at 3:00 PM) and single feeding at 3:00 PM. 330 female and 45 male Cobb 500 broiler breeders were used from 40 to 60 weeks o...