Effects of flock age, place of oviposition and cleaning treatments of hatching eggs on hatchability in broiler breeders

Abstract

SUMMARY: Floor eggs are of economical importance within the broiler breeder industry since they are less suitable for the incubation because of the higher risk of contamination and lower hatchability. The aim of this study was to establish the effects of the flock age and place of oviposition on hatching parameters, and to show whether cleaning practices can improve the incubation results of floor eggs. A total of 4,950 eggs were collected from 3 commercial Cobb 500 breeder flocks at the age of 29 and 64 wk. Eggs were divided into groups depending on the place of oviposition (nest eggs, floor eggs or eggs laid in the nest and put on the floor after cooling). Floor eggs were further divided on eggs with visually clean or dirty shells. Dirty floor eggs were cleaned either by washing or brushing the eggshell. After incubation the basic hatching parameters were measured (fertility, egg weight loss, embryo mortality, contaminated eggs, hatching percentage) as well as the day-old chick weight and length.The results showed that hatchability rate deteriorates with advancing bird age and that place of egg cooling is a critical point for contamination. Eggs cooling down on the floor have a higher risk of contamination than eggs cooling down in the nest. Clean floor eggs had significantly higher degree of contamination compared to nest eggs. It is established that brushing the shell of floor eggs can reduce their contamination and early embryonic mortality in young flocks, although this reduction did not significantly affect the overall hatchability.

Keywords

• broiler breeder
• age
• incubation
• floor egg
• cleaning treatments