Eggshell Quality as Influenced by Clutch Size in Hens Laying Eggs, with Heavy or Light Shell Weight

Abstract

Abdallah, A.G. and Harms, R.H. 1997. Eggshell quality as influenced by clutch size in hens laying eggs, with heavy or light shell weight. J. Appl. Anim. Res., 12: 113–120. An experiment was conducted using Hy-line W 36® hens, 32 wk of age, to study the effect of clutch size on eggshell quality in hens laying eggs with heavy shell weight (HSW) or light shell weight (LSW). A total of 120 HSW or LSW hens were selected according to shell weight as described previously by Abdallah et al. (1993). Two consecutive clutches were recorded for each hen. Egg weight, shell weight (SW), percentage shell (PS) and shell weight per unit surface area (SWUSA) were determined. Both HSW and LSW hens had clutch sizes as short as 2 eggs and as long as 20 eggs. Egg weight decreased linearly with the progressive days in the sequence with a slight increase in last egg. However, SW, PS and SWUSA decreased quadratically with progressive days in the sequence with no significant interaction between HSW and LSW hens. Hens having long clutches (10 eggs or more) showed some fluctuations in eggshell quality in the middle of the cycle. The same pattern was observed with the short clutch hens (6 eggs or less). The data indicate that position of the egg within the clutch had major influence on eggshell quality (up to 1 g difference in shell weight) with no significant interaction between HSW and LSW hens. Also, the long clutches mostly associated with LSW hens did not provide an explanation far poor shell quality.