Insulin-like Growth Factor-1 Gene Polymorphism and Its Effect on Reproductive Performance of Funaab Alpha, Kuroiler and Sasso Chicken Reared in Hot Humid Tropics

Abstract A study was conducted on the effect of chicken genotypes and gene polymorphism of Insulin like Growth Factor-1 (IGFI) on reproductive and egg quality traits in five chicken genotype. A total of 250 chicken comprising 150 FUNAAB-Alpha (50 Normal feather, 50 Naked neck and 50 Frizzle feather), 50 Kuroiler and 50 Sasso were used for this experiment. The chicks were generated through artificial insemination and were raised to maturity on deep litter system. At point of lay, 30 hens per genotype were selected and transferred into a battery cage of one unit per bird to monitor their reproductive performance. Data were collected on the following at first lay; body weight of the bird (WOBAFL), egg weight (WOEAFL) and age (AAFL). For the egg quality traits, a total of 30 eggs for each genotype was collected, with the following parameters: egg (weight, length, and width), shape index, shell thickness, albumen (height, weight), yolk weight, ration of shell, yolk and albumen, and haugh unit was measured. All collected data was subject to analysis of variance using a completely randomized design, of which genotype was the interest factor. At 16 weeks, 1ml of blood was collected from each hen and extraction of genomic DNA from the blood was done. PCR was conducted using the pair of primer and condition as described by Nagaraga, et al. (2000). The PCR amplicons were digested using PstI restriction enzymes following the manufacturer’s procedure. The resulting fragments were analyzed using GenAnalyzer. GenAlEx 6.502 was used for the genetic diversity of the IGFI locus. Data for the association studies was subject to the PROC GLM of SAS 9.2. Results showed the chicken genotypes significantly (P < 0.05) affect all the egg-quality traits except the shell weight, yolk ratio and albumen ratio. The IGFI gene polymorphism had no significant effect (P > 0.05) on egg quality traits except the egg length and egg width were seen to be significantly (P < 0.05) affected. The reproductive parameters of the chickens where significantly (P < 0.05) affected by their genotypes except for the age of the bird at first lay (AAFL). IGFI gene polymorphism had no significant effect (P > 0.05) on the reproductive performance except for the WOEAFL.