Effects of ventilation programme and eggshell thickness on hatchability rate and hatching time of broiler eggs

N Okur,S.A Eratalar

doi:10.4314/sajas.v51i2.8

Abstract

The aim of the research was to determine whether enrichment of the atmosphere in an incubator with carbon dioxide (CO2) and oxygen (O2) and eggshell thickness (EST) affected embryonic death (ED), hatchability of fertile eggs (HFE) and hatching time (HT). A total of 320 Ross 308 eggs were used and the experiment was repeated twice. Eggshell thickness was classified as thin (<31 μm), medium (31 - 32 μm) and thick (>32 μm). The incubators were operated with their internal atmosphere enriched with CO2 (1.57% CO2; 20.23% O2) or O2 (0.50% CO2; 22.44% O2). Embryonic death, HFE and HT data were monitored at three periods, namely early (<486 hours), middle (486 - 492 hours), and late (492 - 510 hours). Early ED, late ED and hatchability of fertile eggs were not affected by EST or by the incubator’s internal atmosphere (P >0.05). Thus, O2 supplementation to the incubator was deemed unnecessary at 822 m altitude. There was a highly significant interaction between EST and HT. Eggs with shells 31 to 32 μm thick hatched at an appreciably greater rate between 486 and 492 hours of incubation (17%) than eggs with thicker (0.6%) or thinner (0.4%) shells in both the CO2 and O2 enriched atmospheres. The hatching rate was significantly higher in the eggs with an intermediate EST than in thick-shelled eggs. A greater proportion of eggs hatched at the late HT as opposed to earlier, regardless of EST.

Highlights

Successful incubation of broiler eggs depends on management of the incubator (French, 1997; Yildirim & Yetisir, 2004) and certain characteristics of hatching eggs such as genetics, age, maintenance and feeding conditions of breeders, egg weight (EW), and eggshell thickness (EST) (Kirk et al, 1980; Narushin & Romanov, 2002; Sarica et al, 2012; Elibol & Turkoglu, 2014; Hammershoj & Steenfeldt, 2015; Yamak et al, 2015; Popova et al, 2019)
They demonstrate the similarity of eggs that were allocated to the treatments (P >0.05)
These eggs were slightly heavier than those used by Kirk et al (1980) and had thinner shells compared with other studies (Christensen et al, 1994; Huwaida et al, 2015 and Yamak et al, 2015)

Summary

Introduction

Successful incubation of broiler eggs depends on management of the incubator (French, 1997; Yildirim & Yetisir, 2004) and certain characteristics of hatching eggs such as genetics, age, maintenance and feeding conditions of breeders, egg weight (EW), and EST (Kirk et al, 1980; Narushin & Romanov, 2002; Sarica et al, 2012; Elibol & Turkoglu, 2014; Hammershoj & Steenfeldt, 2015; Yamak et al, 2015; Popova et al, 2019). The levels of CO2 and O2 in the incubator reportedly determine the rate of embryonic development and may affect incubation and post-hatching performance (Metcalfe et al, 1981; Lourens, 2007; Molenaar et al, 2010; Tona et al, 2013). An atmosphere that is low in O2, such as at high altitudes, can affect incubation efficiency and chick quality negatively The content of O2 in the atmosphere is about 21% at sea level (Stock & Metcalfe, 1984). Low (

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