Effects of pre-incubation upside-down positioning of eggs from breeder flocks with different ages on hatchability and chick quality

Effects of pre-incubation upside-down positioning of eggs (from collection time at the farm until delivery to the hatchery, which can be up to 5 days) and breeder flock age on hatchability and chick quality were investigated. In this study, 5400 eggs from broiler breeder flocks were assigned to two groups (upside-down and normal position eggs as Control group). The birds were divided in three age groups (46, 73 and 107 weeks of age). Each age group had six replicates with 150 eggs per replicate. The results indicated that keeping eggs in an upside-down position reduced (P < 0.05) hatchability by 4.3% compared with the Control (normal position) group. Also, reversed egg positioning significantly increased relative intestine weight (P < 0.05) and percentage of embryo mortality between 18-19 days of incubation (P < 0.01). Flock age affected (P < 0.01) hatchability, egg shape index, chick cull percentage, infertile eggs, total embryo mortality, percentage egg weight loss and chick yield. The lowest hatchability and the highest percentage egg weight loss were observed in flocks with 107 weeks of age.