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 μηι), medium (31 - 32 μηι) and thick (>32 μπι). 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 μπι 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.

ABSTRACT This study investigated the effects of incubator carbon dioxide (CO2) and oxygen (O2) levels, and egg weight (EW) on embryo mortality (EM) and hatchability of fertile eggs (HFE). A total of 1920 hatching eggs were obtained from a middle-aged (41 weeks) ROSS 308 broiler breeder flock. The eggs were classified according to EW as heavy (69.63 ± 0.09 g), medium (65.20 ± 0.04 g) and light (61.11 ± 0.08 g) and randomly allocated to four separate identical incubators. To these incubators, four different incubator ventilation programmes (IVP) classified as control (C; 0.7% CO2 and 20.9% O2), high CO2 (HC; 1.1% CO2 and 20.3% O2), high O2 (HO; 0.6% CO2 and 22.0% O2), and high CO2 + O2 (HCO; 0.9% CO2 21.0% O2) were applied, and EM and HFE were examined. IVP affected EM and HFE; a higher rate of early EM and a lower rate of HFE were obtained from the HO group compared to the HCO group, and a lower rate of HFE was observed in the HO group than to the C group (p<0.05). An association was found between EW and IVP (p<0.05), being more evident in early EM for light eggs. Consequently, IVP; i.e., different CO2 and O2 levels in the incubator affected the hatching results. This is considered to be due to the altitude of the experiment (724m) and the uniform eggs being obtained from the same middle-aged flock, and incubator O2 levels should be taken into consideration, as well as CO2.

ABSTRACT The impacts of breeder age (32 and 55 weeks), egg storage time (2-12 days), setter ventilation program (control-test) on incubation and post-hatch performance of broilers were investigated in this study. Young (Y) and old (O) breeders’ hatching eggs were incubated in two different setters operated by two different ventilation programs as control (C) and test (T). Incubation took place after a short (S) and long (L) time of storage in this study. According to the trial design, eight treatment groups were as YSC, YST, YLC, YLT, OSC, OST, OLC and OLT. In total 9600 eggs and 6400 chicks were used. Early stage embryonic mortality (ED) rates were lower and accordingly hatchability of fertile eggs (HF) were higher (p<0.05) in YS than the other treatment groups. In contrast, incubation performance in eggs hatched in C and T programs were found to be similar. However, interaction between treatments were significant (p<0.05) and ED and HF were significantly (p<0.05) improved at OC. Liveability in growing period was affected (p<0.05) by breeder age but it wasn’t affected by storage time and incubation program. Higher post-hatch performance was achieved in chicks of OST but differences between groups weren’t significant except for chick weights in comparison by breeder age. However, interactions between treatments were significant (p<0.05) and reached the highest post-hatch performance in YST (p<0.05). In conclusion, the long time storage of old breeders’ eggs improved incubation and post-hatch performance when they were incubated at test program.

ABSTRACT The objective of this study was to determine the effects of eggshell color of guinea fowl (Numida meleagris) eggs on eggshell quality and hatchery results. The highest mean grey value (MGV), integrated density (ID), lightness (L*) and Hue angle (H*) values were obtained in eggs with lighter eggshell color. The effects of color difference (DE*) value levels on egg characteristics were evaluated. Eggshell color presented different (p<0.01) MGV, ID, L*, redness (a*), yellowness (b*), H* and Chroma (C*) values. Eggs with lighter color presented thicker eggshells and lower egg weight loss on day 25 of incubation (p<0.05) compared with intermediate and darker eggs. Eggshell color did not have any significant effect on fertility and hatchability (p>0.05). In conclusion, under the conditions of the present study, eggshell color influenced eggshell thickness and weight loss, but not hatching parameters of guinea fowl eggs. Further studies on this subject should be carried out.

The aim of this study was to investigate the effect of thermal conditioning of broiler chickens during embryonic development on subsequent performance under standard rearing conditions. During incubation eggs from 32-, 45- and 56-week old Ross 308 broiler parent stock were subjected to a 2 h heat shock of 39 °C on days 14 and 15 of incubation. Eggs in the control were incubated throughout incubation at 37 °C. Chicks were feather sexed and equal numbers of each sex were placed in each pen per treatment, and reared for 42 days. Live weight, mortality and feed conversion ratio (FCR) were used as measures of performance. The final (six-week) live weights of broilers from young, mid and older parents for the treatment and control groups were 2113 ± 13.8 vs. 2159 ± 20.0, 2084 ± 29.2 vs. 2139 ± 20.0 and 2096 ± 17.6 vs. 2131 ± 24.3 g, respectively. The six-week live weight of the heat-treated group (2098 ± 12.0 g) was significantly lower than that of the control (2143 ± 12.2 g). The 1-6 week mortality figure was significantly lower in the heat-treated group of chickens from the young (83) and mid parent (77) groups compared to their controls (130 and 119), respectively. However, in the treatment group the incidence of mortality in broilers from the older parent group was significantly higher (105) than that of the control (79). The overall mortality without considering the parent age group was significantly lower in the treatment group (265) than in the control group (328). Mean FCR (g feed/g gain) of the chickens of the three parent groups was 1.79 ± 0.02 vs. 1.75 ± 0.03, 1.85 ± 0.03 vs. 1.77 ± 0.02 and 1.80 ± 0.03 vs. 1.77 ± 0.03 for the treatment vs. control groups, respectively, but the difference was significant only in the mid age parent group. These results suggest that prenatal thermal conditioning is not detrimental to broiler growth under standard rearing conditions in the absence of thermal stress. However, survival rate was improved but live weight and FCR were in some cases significantly poorer.