Improving hatching performance and chick quality in egg-type layers by modulating the incubation temperature

This study investigated the effects of variations in incubation temperature on hatchability and early post-hatch performance in Prelux-G laying hens. During the first 18 days of incubation, eggs were exposed to one of five temperature regimes: Group A (37.5 °C for six days, then 37.0 °C), Group B (37.5 °C followed by 38.0 °C), Group C (37.0 °C followed by 37.5 °C), Group D (38.0 °C followed by 37.5 °C) and Control Group K (constant 37.5 °C). In the last three days of incubation, all groups were kept at a uniform temperature of 37.2 °C. A total of 3040 eggs were used, and incubation parameters were evaluated with both individually marked and group-monitored eggs. Lower incubation temperatures (groups A and C) resulted in significantly higher egg weight loss (P<0.001), with group A experiencing the greatest loss. Group A also had the longest incubation period, while group D had the shortest (P<0.001). The chicks in groups B and D had a significantly higher body weight at hatching (P<0.001). Longer egg storage (eight to nine days) had a negative effect on hatchability (P<0.05), with the lowest hatch rates observed after eight days. Notably, initial exposure to 38.0 °C (Group D) partially counteracted this decline, improving hatchability to 79.2%. Embryonic mortality and sex ratio were not significantly affected (P>0.05). Although differences in body temperature and chick length were already observed on the first day (P<0.05), these did not persist after days 12 and 27. Early thermal manipulation, especially with initially higher temperatures, can improve hatchability and chick quality in commercial hatcheries.