Growth Trajectory of the Nigerian Indigenous and Exotic Strains of Chicken Embryos during Incubation under Nigerian Condition

This study investigated embryonic growth and early growth rate in three strains of chicken. A total of nine hundred hatching eggs, 300 each from 3 strains of chicken, were used for this study. The strains of chicken used were Nigerian indigenous chicken (NIC), Isa Brown (IB) and Nera Black (NB) strains. Twenty eggs per strain were randomly selected for breakout at Embryonic Days (ED) 7, 11, 15, and 18 of incubation to determine embryonic weight, egg weight, egg weight loss and shell weight loss during incubation. Embryonic weight was monitored on ED 7, 11, 15, and 18. The results showed that the NIC had greater (P 0.05) Haugh unit (71.78) than those of NB (53.23) and IB (52.36). Also, percentage egg yolk weight in NIC (28.74) was higher than that of NB (25.87) but similar to that of IB (26.55). Strain significantly (P 0.05) affected the percentage shell weight from ED 0 until ED15, except at ED18, where they were similar. At ED7, the NB(6.12) showed significant weight loss compared to that of the IB (4.16) but the weight loss was similar to that ofthe NIC chickens. At ED7 and 18, there were significant differences (P 0.05) in the embryo weight as percentage of egg weight between the strains. NIC showed a higher embryo weight as percentage of egg weight than the two other strains which were similar in value. It was concluded that the present incubation protocol is adequate for NIC as the embryo weight (expressed as percentage of egg weight) was superior to those of the exotic strains.