The purposes of this study were to determine the effects of oviposition time on egg quality and to examine the possibility of estimating egg shell weight using a formula. The interactions in some egg quality measurements were also studied. During the experiment, 80 white and 64 brown layers were housed in cages and fed with a standard layer ration. The birds were given 17 hours of light per day throughout the experiment. Egg quality was checked four times with two week intervals. At each check, eggs were collected at 09.oo , 12.oo and 15.oo, on consecutive days. Egg weight (EW), egg specific gravity (ESG) and shell weight (SW) were measured, and then shell ration (SR) and shell weight per unit surface area (SWUSA) were calculated. In addition, the SW was estimated by two formulae using EW and ESG. The data from white and brown layers were analysed separately. The effects of oviposition time and age of hens were tested with variance analysis. The correlation coefficients between quality measurements were determined. The effect of age was not significant (p>0.05). Collection time had a significant (p

The purposes of this study were to determine the effects of oviposition time on egg quality and to examine the possibility of estimating egg shell weight using a formula. The interactions in some egg quality measurements were also studied. During the experiment, 80 white and 64 brown layers were housed in cages and fed with a standard layer ration. The birds were given 17 hours of light per day throughout the experiment. Egg quality was checked four times with two week intervals. At each check, eggs were collected at 09.oo , 12.oo and 15.oo, on consecutive days. Egg weight (EW), egg specific gravity (ESG) and shell weight (SW) were measured, and then shell ration (SR) and shell weight per unit surface area (SWUSA) were calculated. In addition, the SW was estimated by two formulae using EW and ESG. The data from white and brown layers were analysed separately. The effects of oviposition time and age of hens were tested with variance analysis. The correlation coefficients between quality measurements were determined. The effect of age was not significant (p>0.05). Collection time had a significant (p