Effects of egg preheating on hatchability and chick quality in partridge and guinea fowl

By preheating the eggs before incubation, all embryos are set to the same developmental stage. In this manner, the hatching window can be shortened and hatchability can increase. Before incubation, a total of 491 partridge and 460 guinea fowl eggs were preheated at 28 & DEG;C and 60% relative humidity for 0, 4, 6, and 8 hours. Preheating significantly affected hatchability in both partridge and guinea fowl eggs. In partridge eggs, the hatchability of fertile eggs was 73.31% in the 0-hour preheated group and 92.94% in the 8-hour preheated group. The hatching rates of guinea fowl eggs were 69.60, 80.07, 84.38 and 78.23% in the 0, 4, 6 and 8 hours preheated groups, respectively. Partridge keets hatched from preheated eggs had significantly better quality, while guinea fowl keets did not differ in quality.