Effects of floor eggs on hatchability and later life performance in broiler chickens

Two experiments were conducted in which effects of floor eggs, washed floor eggs, and clean nest eggs were investigated on incubation characteristics and performance in later life of broiler chickens. In both experiments, a young and an older breeder flock were used in a 3×2 factorial design during incubation. In the second experiment, male and female chickens were reared separately until d 35 of age in floor pens. During this grow out trial, an extra group was created in which chickens obtained from clean nest eggs were mixed with chickens obtained from floor eggs, meaning that grow out period was set up as a 4×2×2 factorial design with 4 egg types, 2 breeder ages, and 2 sexes. In both experiments, fertility and hatchability of fertile eggs were lower in floor and washed eggs than in clean nest eggs (hatchability: experiment 1: 74.4 vs. 70.6 vs. 92.6% for floor eggs, washed floor eggs and clean nest eggs, respectively, P<0.001; experiment 2: 78.3 vs. 81.7 vs. 90.2%, respectively, P<0.001). In experiment 2, BW at d 0 of chickens obtained from clean nest eggs was higher than that of chickens from floor eggs and washed floor eggs (41.5 vs. 40.4 and 40.3 g, respectively; P<0.001). This difference disappeared during the grow out period and was absent at slaughter age at d 35 of age. Feed intake (FI), feed conversion ratio (FCR), and mortality during the grow out period were not affected by egg type. Incidence and severity of hock burns and footpad dermatitis were not affected by egg type or breeder age. Litter friability at d 35 of age tended to be lower in pens with chickens obtained from washed floor eggs compared to clean nest eggs. We conclude that incubation of floor eggs or washed floor eggs resulted in lower fertility and hatchability compared to clean nest eggs, but that performance during the grow out period was not affected.