Effects of shell thickness, shell pores and egg weight loss on hatchability on Japanese quail eggs

摘要

This study was conducted to determine the effects of eggshell thickness, pores, and weight loss on hatchability on Japanese quail eggs. A total of 477 eggs, collected within 5 days, placed in an incubator after determining individual egg weights, and eggs were individually weighted on 5, 10, 14, and 18th days of incubation. Percentage egg weight loss was calculated for individual eggs for each incubation interval. On day 18 of incubation, all unhatched eggs were opened and examined macroscopically for evidence of stage of embryonic development. Egg types were classified as infertile (INF), early dead (ED), late dead (LD), embryos that pipped the shell but failed to emerge (PIP) and hatched (H). Dry chicks weights from hatched eggs were obtained on day 18. Shell thickness and porosity were determined in all egg types. The greatest egg weight loss until the day 14 of incubation was observed in ED eggs; it was intermediate in LD and INF eggs, whereas it was low in H and PIP eggs (P<0.05). The egg weight loss between 14-18 days was high in H and ED eggs, and low in other types of eggs (P<0.05). The egg weight loss between 0-18 days were observed in all egg types (H: percent 29.26+-0.26, ED: percent 25.00+-2.05, LD: percent 18.77+-0.77, PIP: percent 15.04+-1.40, and INF: percent 16.41+-1.22; P<0.05). In three different eggshell regions (air space, equator, small end), a high number of pores was observed in H eggs, and the number of pores was low in PIP eggs (P<0.05). The lowest shell thickness was observed in air space and small end region of ED eggs, and in equator regions of PIP eggs (P<0.05).