“…Thus, good quality eggshells must occur throughout all the reproductive life of breeders since they influence the embryonic development (Tůmová & Gous, 2012). The eggshell quality can be affected by genotype, breeder age, room temperature (Tůmová et al, 2014) and nutrition (Londero et al, 2015;Tůmová & Gous, 2012), on the other hand, the laying time does not influence the eggshell quality (Gumulka et al, 2010;Tůmová et al, 2014).…”