Abstract

This study was aimed to standardise the pre-incubation storage period of hatching eggs of Kuttanad ducks for getting better hatchability. The hatching eggs were collected from breeding flocks of Kuttanad ducks for seven consecutive days and the eggs collected on each day were stored at a temperature of 17 to 18°C with 75 per cent relative humidity (RH). The eggs which were subjected to 1-7 days storage period formed the treatments and were incubated at 37.5°C with the RH of 60 per cent in the setter for first 24 days and at 36.9°C with the RH of 68 per cent for the remaining 4 days in the hatcher. The process was repeated for four consecutive weeks. The breakout study was carried out in the discarded eggs at 9th, 24th and 28th days of incubation to assess the stage of embryonic death. The percentage of fertility, hatchability on total egg set (TES), hatchability on fertile egg set (FES) and also percentage of early embryonic mortality (EEM), mid-embryonic mortality (MEM), late embryonic mortality (LEM), pipped eggs with live chick (PL) and weaklings (W) on fertile egg set were calculated and analysed. This study revealed no significant difference in fertility among treatments. The hatchability on FES were significantly (p<0.05) higher in egg stored for 1-2 days followed by 3-4, 5 and 6 days stored eggs and the same was lowest in 7 days stored eggs due to the significantly (p<0.05) higher early embryonic death. This could be due to loss of carbon dioxide (CO2 ) and water from the egg, increase in pH of egg albumen, liquefaction of albumen and deterioration of yolk due to prolonged storage.

Keywords : Kuttand duck eggs, preincubation storage, hatchability, embryonic mortality