Efficacy of three sealing methods on hatchability of microcracked eggs from broiler breeder hens

Background: Shell fragility of hatching eggs can have negative implications on the economic performance of hatcheries. Objective: To determine the efficacy of sealing eggshell micro cracks with either coloured or uncoloured nail varnish, and molten paraffin on hatchability, embryonic mortality (EM) and hatched chick weight (CW). Methods: Eggs (n= 576) with micro-cracks were assigned among four groups (n=144 each group) for a 21 d incubation period. One group was untreated (CE). In the other groups, the micro cracked area of eggshells was sealed with uncolored nail varnish (NV), colored nail varnish (CV), or molten paraffin wax (MP). A positive control group of un-cracked eggs (UE) was also included (n= 144). Results: The eggshell sealant treatments allowed normal conductance related to egg weight loss after 18 d of incubation (11.45%), and chick weights were normal among treatment groups (44.7 g). Hatchability and embryonic mortality in the early and late incubation periods of the NV group was similar to UE (84.02 vs 86.11% for hatchability, 6.95 vs 10.42% for EM on days 1-10, and 2.08 vs 1.39% for EM on days 18-21 respectively; p>0.05). The CV group had lower hatchability than the NV (77.77 vs 84.02% respectively; p<0.05), whereas MP showed similar hatchability compared to the CE group (59.72 vs 72.92%, respectively p>0.05). Conclusions: Application of uncoloured nail varnish on shell micro-cracks improves egg hatchability.