The study aimed to determine the effect of preincubation of hatching eggs of grey partridge ( Perdix perdix ) on hatch window dynamics, hatchability parameters, and physicochemical changes in extraembryonic structures during incubation. The experiment was conducted on 630 hatching eggs obtained from a breeder flock at 56 weeks of age. The eggs were divided into two groups: a control group (CON; standard storage conditions) and an experimental group (PRE; subjected to pre-incubation under controlled heating conditions at 37.7°C). In the PRE group, the following preincubation model was applied: 6 h of heating, 12 h of cooling, 12 h of heating, and 6 h of cooling prior to the onset of proper incubation. Hatchability, embryo mortality, hatch window characteristics, and chick quality were evaluated. Changes in the physicochemical properties of the eggshell, albumen, amniotic fluid, and yolk were analyzed on selected days of incubation. Preincubation did not significantly affect hatchability or embryo mortality. However, it significantly modified the hatch window by accelerating and synchronizing the hatching process. Chick quality did not differ between the groups. However, the relative body weight of chicks was lower in the PRE group (P = 0.006). Egg weight loss was higher in the PRE group only during the first week of incubation (P = 0.023). A significant effect of preincubation on the physicochemical properties of egg contents was also observed, including a decreased pH of albumen and amniotic fluid, changes in viscosity, and increased lysozyme activity, particularly in the amniotic fluid. Changes in the content of selected mineral components in the yolk were also detected. Preincubation of grey partridge eggs effectively improved hatch synchronization without negatively affecting hatchability or chick quality. The accompanying physicochemical changes may indicate mechanisms supporting embryonic development and protection.
Biesek et al. (Wed,) studied this question.