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.

The objective of this study was to investigate the effect of oxygen supplementation on broiler eggs in a hatchery at high altitude on the growth performance and ascites syndrome of broilers reared at low altitude. The treatment groups were low altitude with no oxygen supplemented in the hatchery (LA-NOX); high altitude with oxygen supplementation in the hatchery (HA-OX); and high altitude with no oxygen supplemented in the hatchery (HA-NOX) group. Growth performance, heart weight, the concentrations of the hormones, T3,T4 T3/T4, and and plasma concentrations of haematocrit, haemoglobin, glucose and parameters of ascites syndrome during the growing period were investigated. A total of 243 one-day-old broilers were used for this study. During the growing period, excluding days 7, 28 and 35, oxygen supplementation at high altitude did not affect the live weight of broilers compared with the HA-OX and HA-NOX groups. The cumulative feed consumption was determined to be lower in the LA-NOX group and the same in the HA-OX and HA-NOX groups on the 42nd day. Between 21 and 42 days old, the LA-NOX group had a better feed conversion ratio (FCR) than the HA-OX and HA-NOX groups. Chick weight (CW), yolk sac weight (YSW) and chick heart weight (CHW) were higher in the LA-NOX group than in the HA-OX and HA-NOX groups. At 42 days old, there were no differences between the groups in heart weight, right ventricle weight (RV), left ventricle and septum (LV+Sept.), total ventricle (TV) weight and the RV : TV ratio. The plasma T3 level was lower in the LA-NOX group than in the HA-OX and HA-NOX groups and T4 levels were higher in the HA-OX than in the others at 42 days old. The hypoxic conditions that occurred during the embryonic stage - which altered endogenous functions of prenatal chicks and affected several blood parameters, and oxygen supplementation at high altitude - improved chick quality. However, it did not improve subsequent FCR and feed consumption performance of chickens when they were reared at low altitude.

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.