Evaluation of some eggshell parameters during the embryogenesis in turkeys

Abstract

The aim of the experiment was to investigate the traits of eggshells of incubated turkey eggs, produced by turkeys at 34 and 46 weeks of age and to evaluate their effect on the development of embryos. This study was performed in the turkey farm of the Poultry and Rabbit Selection, Population Genetics and Technology unit at the Agricultural Institute – Stara Zagora in 2016. The eggs from turkeys of the North-Caucasian Bronze (NCB) breed were investigated. One hundred and twenty eggs were randomly collected from 34 and 46-week-old turkeys. The eggs were examined by the 9th day of incubation and before the transfer to the hatcher. The numbers of dead embryos and their eggshell parameters were registered. The shells of eggs of viable hatchlings were also analysed. Egg weight, shell weight, shell thickness (at sharp end, blunt end and equator), number of pores, egg surface area and shell density of eggs with embryos dead and hatched from 34 and 46-week-old turkeys were investigated. At 34 and 46 weeks of age, the weight of eggshells of eggs with early dead and late dead embryos was significantly higher (8.35 g at р < 0.001 and 8.14 g at р < 0.01) compared to the eggshell weight of hatched eggs - 7.27 g. There were no differences in the thickness of shells of dead and hatched eggs, laid by 34- and 46-week-old turkeys. The total number of pores on the shell surface of early dead eggs was lower when compared to the parameter of late dead eggs and hatched eggs from turkeys at 34 and 46 weeks of age. Eggs with dead embryos had thicker shells than hatched eggs in turkeys at the two studied ages (34 and 46 weeks of age). This requires further studies on the influence of the quality of the egg shell on the development of embryos.