Effects of pre-incubation egg storage length and orientation on hatching traits in Transylvanian naked neck chickens

Abstract Eggs from Transylvanian naked neck (TN) chickens (n = 560) were stored in cold room (at 16 ± 1.5oC) in daily batches of 80 eggs each, for 1, 2, 3, 4, 5, 6 or 7d either with broad (BEU) or narrow end up (NEU). Additional day in storage caused significant (P < 0.001) loss in egg weight. Dead in germ (DIG) followed (P < 0.001) the pattern: 5d < 6d < 2d = 1d < 4d < 7d. DIG in 3d group was similar to both 4d and 7d. However, dead in shell (DIS) took (P < 0.001) 6d > 7d > 1d = 4d = 5d > 3d pattern. DIS in 2d stood in-between 6d and 7d groups. Similar hatchability of set eggs (HSE; P > 0.05) was recorded in eggs stored for 1d, 2d, 3d and 4d. These were significantly (P < 0.001) higher than others. Storage for 5d resulted in better HSE than 6d and 7d. HFE was in descending order: 1d > 2d > 3d > 4d = 5d > 6d > 7d. BEU eggs (P < 0.001) had higher DIG and DIS and lower HSE and HFE than those stored NEU. Hatch window (HW) was significantly (P < 0.001) influenced by length of storage. Storage for 4d and 5d exhibited longer HW than 2d, 3d and 7d. Shortest HW was observed in eggs stored for 1d. Hatching (P < 0.05) commenced earlier and took longer time in BEU eggs (472h; 36h) than in NEU eggs (478h; 30h) respectively. Chicks in 3d (17.4 cm) were (P < 0.01) longer than those from 4d (16.9 cm), but the two groups were similar to other groups. In conclusion, storage of TN chicken eggs should not exceed 4d. Storage in NEU orientation gave better hatching traits than BEU.