Influence of egg storage length and orientation on hatching traits and spread of hatch in Transylvanian naked neck chickens

Effects of egg storage length and orientation on hatching traits and spread of hatch were determined in Transylvanian naked neck chickens. Eggs (n = 640) stored in a cold room (16 ± 1.5°C, 75 ± 1.5% RH) in batches of 160 eggs each, for 1, 3, 5 or 7 days were used. Half of each batch was stored with a broad end up (BEU) and the other in a narrow end up (NEU). Eggs were incubated in a two-stage incubator (37.5°C, 64% RH). Storage length caused a significant increase in egg weight loss (EWL; p < 0.001). Egg fertility (FERT) was significantly lower in 7 days than in 1, 3 and 5 days stored eggs (p < 0001). Dead in shell (DIS) was lower (p < 0.001) in 1-day storage than in other lengths (p < 0.001). Hatchability of total (HSE) and fertile eggs (HFE) decreased (p > 0.001) gradually from 1 to 7 days, though 3 and 5 days were found to be similar. Hatching commenced earlier (p = 0.055) in 5 days than 1-day storage. Incubation time at 100% hatch, hatch window and spread of hatch were not (p > 0.05) affected by storage length. At the end of the hatch, longer storage than 1 day caused 45, 45 and 15 min/day delay in hatching for 3, 5 and 7 days storage respectively. The chicks from 3 days storage (17.3 cm) were longer (p = 0.05) than those from 5 (17.1 cm) and 7 days groups (17.1 cm). Higher DIG and DIS but lower HSE and HFE (p < 0.05) were recorded in BEU than in NEU orientation. Earlier commencement of hatch (CH) was recorded in BEU than in NEU eggs. There were significant (p < 0.05) interactions between storage length and orientation in FERT, DIG, HSE, HFE, CH and hatch windows. To achieve HFE up to 70%, eggs could be stored for up to 7 days in NUE orientation but should not exceed 3 days in BEU orientation.