Effects of Egg Size and Different Levels of Humidity during Incubation Period on the Embryonic Development, Hatching Percentage and Chicks Yield of Broiler Breeder

Abstract

Background: This experiment was performed to investigate the effect of humidity and egg size on the hatchability, embryonic development and chicks yield in ROSS 308 broiler breeder flock. Methodology: The study was conducted in a completely randomized design with a 3×3 factorial arrangement. The treatments involved three levels of wet bulb humidity (°F WB) including 82, 82.5 and 83°F and three different egg sizes including small, medium or large. Results: The main effect of humidity level on the total and fertile hatchability (%) as well as the weight of one-day-old chicks were significant (P<0.05). Treatment with humidity of 82.5°F enhanced total and fertile hatchability, while humidity of 83°F increased one-day-old chick weight (P<0.05).A better total and fertile hatchability (%), fertility (%), chick yield (%) was observed in medium egg size group (P<0.05). However, the chick weight was greater in large egg size group (P<0.05). The lowest embryonic mortality was belong to medium egg size treatment (P<0.05). Conclusion: According to the results, it was concluded that humidity of 82.5°F as well as the medium egg size showed a better impact on the incubation performance.