منابع مشابه
Yolk and albumen corticosterone concentrations in eggs laid by white versus brown caged laying hens.
Maternal stress in birds can have permanent transgenerational effects through the transmission of stress hormones to offspring via the egg yolk. Previous studies have shown that White Leghorn hens show a heightened response to stress compared with Hy-Line Brown hens, producing significantly more corticosterone and displaying longer bouts of tonic immobility after handling, whereas baseline leve...
متن کاملInfluence of the microstructure on the shell strength of eggs laid by hens of different ages.
1. The eggshell is a bioceramic material constructed of columnar calcite crystals preferentially oriented with their c-axis perpendicular to the shell surface. 2. The influence of microstructure (crystal size, shape and crystallographic orientation of crystal grains) on the mechanical properties of eggshells (shell strength) was investigated using eggs from hens of different ages. 3. There was ...
متن کاملThe quality comparison of eggs laid by laying hens kept in battery cages and in a deep litter system
At present the laying hen rearing is transformed into alternative housing systems which include a deep litter system. As for the poultry nutrition, the replacement of animal protein with vegetable protein in poultry feed is applied. Therefore, in an experiment we evaluated the quality of eggs from laying hens in the cage system as compared to the deep litter system with vegetable protein substi...
متن کاملThe Effect of Eggshell Ultrastructure on Hatchability Percentage of Eggs Laid from Naked Neck, Frizzled and Normally Feathered Hens
This experiment was designed to evaluate the effect of naked neck (Na) and frizzle (F) genes on eggshell ultrastructure at different intervals of incubation period. 81 eggshell samples (9 samples/ genotypes/ incubation studied intervals) were taken before incubation period, at 12 days of incubation period and after hatching. Before incubation period, the present results showed that the presence...
متن کاملLutein, zeaxanthin and meso-zeaxanthin content of eggs laid by hens supplemented with free and esterified xanthophylls
The xanthophyll carotenoids lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ) are found at the macula, the central part of the retina, where they are referred to as macular pigment (MP). MP is studied in human subjects because of its proven role in enhancing visual function and its putative role in protecting against age-related macular degeneration. These benefits are probably due to the ant...
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ژورنال
عنوان ژورنال: Science
سال: 1907
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.26.656.119