ABSTRACTThe aim of the current study was to determine the effects of low (33.3-36.7 ˚C), control (37.8-38.2 ˚C) and high (38.9-40.0 ˚C) eggshell temperatures (ESTs) between days 10-18 of incubation on broiler performance and susceptibility to ascites. The effects of different ESTs on hatchling weight were significant. The highest residual yolk sac weight (7.7 g) and relative yolk sac weight (18.7%) were observed in high EST group, whereas the highest yolk-free body weight (36.22 g) was obtained in the control group. Relative post-hatch heart weight was lower in the high EST group (0.64%) compared with the control (0.84%) and low (0.88%) EST groups. At 6 weeks of age, body weights of broilers of the low, control, and high EST groups were 2172.6, 2543.9, 2282.6 g respectively. During the 6-week life span, the feed conversion ratio of broilers in the low (1.86) and high (1.83) EST groups was significantly worse than of those in the control EST group (1.68). Higher packed cell volume (PCV) and red blood cell (RBC) values were obtained in the high EST group relative to the other groups, whereas hemoglobin (Hb) level was lower in the control group than in the others. The relative heart weights and right ventricular to total ventricular (RV:TV) ratio for low, control, and high EST group were 0.46, 0.40, 0.37 g and 0.27, 0.28, 0.33% respectively. In conclusion, incubation length, yolk sac absorption, residual yolk sac weight, yolk-free BW, post-hatch performance, and heart, blood parameters, abdominal fluid accumulation at slaughter age are affected by changes in EST between incubation days 10 to 18.

This study was carried out to determine the effect of live weight, male to female ratio and breeder age on egg weight and the hatching characteristics in Japanese quails (Coturnix coturnix japonica). Female quails at the age of six weeks, were weighed individually and separated into three weight groups depending on their live weights. The groups were classified as light (170-200 g), medium (201-230 g) and heavy (> 230 g). The male quails to be mated with these groups were selected from the individuals with mean live weight of 200-220 g. Groups were placed in the pens at male : female ratios of 1:1, 1:2, 1:3, 1:4 and 1:5. Egg weight was significantly lower in the light group compared with the eggs obtained from the females with medium and heavy live weight. Egg weight increased in accordance with increasing breeder age. Live weight, male to female ratio and breeder age had a significant effect on fertility and hatchability. Fertility increased with an increase in live weight. The highest fertility was found in the group with male to female ratios of 1:2 and 1:3. Fertility at the ages of 11-14 and 15-18 weeks was higher than those of 7-10 and 19-22 weeks of age.

The present study was carried out with the aim of determining the effects of storage temperature and storage position on embryonic mortalities in ostrich eggs. A total of 229 ostrich eggs was collected from two commercial ostrich farms. The effects of storage temperature on embryonic mortality differed. Embryonic deaths (totalled for early, medium and late incubation) were determined at respectively 28.6, 32.0, 42.9% in groups of eggs from stored immediately after collection for seven days at 16 °C, 21 °C and 25 °C. Embryonic mortality was not affected by storing eggs for one week at 16 °C in either the vertical position (with the aircell at the top, or the aircell at the bottom) or the horizontal position. The percentage of embryonic mortalities was 25.8, 26.7, 24.1 for the different storage positions, respectively. These results indicate that ostrich eggs must be stored at 21 °C or less after collection to maximise hatchability and that embryonic survival is not affected by storing position.