this experiment was designed to evaluate the effects of different sources of calcium at different rates and cholecalciferol(vitamin d3) on the performance and egg quality of hy-line w-36 laying hens. in this study a total of 648 hens were managed in a completely randomized design using a factorial arrangement of 3 × 3 × 2 treatments, with three calcium sources (oyster shell, os; ground limeston...

an experiment employing a factorial arrangement of three levels (0, 8 and 16%) of canola meal (cm), two levels (0.15 and 0.25%) of nonphytate phosphorus (npp), and two levels (0 and 450 unit/kg; as fed basis) of microbial phytase was conducted using 216 hy-line w36 laying hens from 39 to 47 weeks of age. the birds receiving cm consumed more (p < 0.05) feed than birds receiving corn-soybean meal...

This study aimed at evaluating the effect of dietary calcium levels and the replacement of calcium sources with different particle size compositions on the performance and egg quality of brown layers in their second egg production cycle. A randomized block experimental design was applied with 12 treatments in a 3x4 factorial arrangement: three calcium levels (2.6, 3.2, 3.8 %) and four combinati...

In this study, it was aimed to determine the internal and external quality traits of the Guinea fowl eggs as well as the phenotypic correlation among the these traits. Totally 100 Guinea fowl eggs were collected in three sequential days were used for this study. The birds were housed at Poultry Research Unit of the Department of Animal Science, Faculty of Agriculture, University of Akdeniz. Val...

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...

The ultrastructure of an eggshell is considered the major determinant of eggshell quality, which has biological and economic significance for the avian and poultry industries. However, the interrelationships and genome-wide architecture of eggshell ultrastructure remain to be elucidated. Herein, we measured eggshell thickness (EST), effective layer thickness (ET), mammillary layer thickness (MT...

Th e aim of the present trial was to study the eff ect of two diff erent dietary phosphorus (P) levels on the laying performance in long-term (17 months) egg production and egg shell quality in terms of strength and thickness from the 7th to 17th month of laying. In case of eggshell quality parameters the time eff ect as well as the interaction between dietary P levels and time were also examin...

Th e aim of the present trial was to study the eff ect of two diff erent dietary phosphorus (P) levels on the laying performance in long-term (17 months) egg production and egg shell quality in terms of strength and thickness from the 7th to 17th month of laying. In case of eggshell quality parameters the time eff ect as well as the interaction between dietary P levels and time were also examin...

the experiment was designed to study the changes in production performance and egg quality of old laying hens after injection of different doses of growth hormone (gh) and testosterone (ts). a total of 160 old laying hens (hyline w-36) at 73 wks of age were randomly assigned to four treatments with four replicates and 10 birds in each replicate in a completely randomized design. treatment group...

Novel and traditional eggshell quality measurements were made from up to 2000 commercial pedigree hens for a candidate gene association analysis with organic eggshell matrix genes: ovocleidin-116, osteopontin (SPP1), ovocalyxin-32 (RARRES1), ovotransferrin (LTF), ovalbumin and ovocalyxin-36, as well as key genes in the maintenance and function of the shell gland [estrogen receptor (ESR1) and ca...