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...

The avian embryo resorbs most of the calcium for bone formation from the calcite eggshell but the exact mechanisms of the resorption are unknown. The present study tested whether this process results in variable fractionation of the oxygen and carbon isotopes in shell calcium carbonate, which could provide a detailed insight into the temporal and spatial use of the eggshell by the developing em...

No single hypothesis is likely to explain the diversity in eggshell coloration and patterning across birds, suggesting that eggshell appearance is most likely to have evolved to fulfill many nonexclusive functions. By controlling for nonindependent phylogenetic associations between related species, we describe this diversity using museum eggshells of 71 British breeding passerine species to exa...

Potentially, pathogenic bacteria are one of the main infective agents against which a battery of chemical and physical barriers has evolved in animals. Among these are the secretions by the exocrine uropygial gland in birds. The antimicrobial properties of uropygial secretions may prevent colonization and growth of microorganisms on feathers, skin and eggshells. However, uropygial gland secreti...

Abnormalities in the histo- and ultrastructure of the amniote eggshell are often related to diverse factors, such as ambient stress during egg formation, pathologies altering the physiology of the egg-laying females, or evolutionarily selected modifications of the eggshell structure that vary the physical properties of the egg, for example increasing its strength so as to avoid fracture during ...

The effects of housing systems on the calcium requirement for eggshell production, eggshell quality and on the breaking strength of the hen’s tibia were evaluated. Unenriched cages (UN) (24 laying hens), enriched cages (EN) (16 laying hens) and floor system (FS) (24 laying hens) were used in this experiment. The eggshell production of laying hens from 19 to 66 weeks of age was higher (P < 0.01)...

The secretion of the eggshell by the follicle cells in the desert locust, Schistocerca gregaria, was studied using the electron microscope. The 3 layers of the eggshell, the vitelline membrane, the endochorion, and the exochorion, are produced in sequence over a short period of about 30-36 h. The follicle cells contain little rough endoplasmic reticulum (RER) and small inconspicuous Golgi bodie...

As a consequence of modernization, industry is spread in the whole world, one of the industries that producing a wastewater as a by-product, iron and steel industry. The result is a huge amount of wastewater that contaminated with iron and steel. Biosorption techniques especially with a natural low cost adsorbent material, namely chicken eggshell is gaining an important goal for treating with a...

Remote regions such as the Antarctic have become increasingly important for investigations into far-reaching anthropogenic impacts on the environment, most recently in regard to the global mercury cycle. Spatial patterns of mercury availability in four regions of the Antarctic Peninsula were investigated using three species of sympatrically breeding Pygoscelis penguins as biomonitors. Eggshells...

The objective of this study was to get a comprehensive understanding of how genes in chicken shell gland modulate eggshell strength at the early stage of active calcification. Four 32-week old of purebred Xianju hens with consistent high or low shell breakage strength were grouped into two pairs. Using Affymetrix Chicken Array, a whole-transcriptome analysis was performed on hen's shell gland a...