A study was conducted to evaluate the effect of 25-hydroxyvitamin D3 (25-OHD) with different levels vitamin (VD3) during rearing period (1–20 weeks) on laying hen performance, bone quality, and eggshell quality. total four hundred 1-day-old Lohman pullets were randomly allotted into a 2 × factorial design dietary VD3 (300 2800 IU/kg) 25-OHD (0 56 μg/kg). Each treatment had five replicates 20 he...

in this experiment, the effects of fennel and thyme extracts with and without flaxseed were investigated on performance and egg quality of leghorn-type laying hens (hy-line w-36). 200 laying hens from 26 to 38 weeks of age were assigned to five dietary treatments with five replications. the treatment groups were: 1) control (a diet without any additives); 2) control diet plus fennel (40 mg/kg f...

M. Çabuk, M. Bozkurt, F. Kırkpınar and H. Özkul Department of Poultry Science, Akhisar Vocational School of Celal Bayar University, 45210, Manisa-Turkey Poultry Research Institute, Erbeyli 09600, Aydın-Turkey Department of Animal Science, Agricultural Faculty of Ege University, Bornova 35100, Izmir-Turkey __________________________________________________________________________________________...

Oviparous animals have evolved multiple defenses to prevent microbes from penetrating their eggs and causing embryo mortality. In birds, egg constituents such as lysozyme and antibodies defend against microbial infestation, but eggshell pigments might also impact survival of bacteria. If so, microbes could exert an important selective pressure on the evolution of eggshell coloration. In a previ...

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...