Factors influencing the hatching performance of duck eggs

Abstract 1. Indigenous nondescript duck eggs hatched better, with higher fertility and lower embryonic mortality than Khaki Campbell eggs. 2. A range system of rearing, with mass mating, resulted in a significant improvement in fertility over deep litter rearing with pen mating. 3. A linear improvement in fertility occurred with increase in egg weight from 60 to 75 g, but the fertile hatchability was significantly in favour of medium‐sized (65 to 70 g) eggs. 4. Storing duck eggs at 16 ± 2°C and 75 ± 5% relative humidity for more than 6 d significantly increased early embryonic mortality and thereby reduced the hatchability. 5. Either spraying chlorinated (50 mg/l) lukewarm water on eggs or cooling eggs to room temperature for 30 min/day, during days 5 to 25 of incubation, improved fertile hatchability; a combination of these two methods did not show any improvement in fertile hatchability.