IGF-II gene polymorphism and its effect on economic traits in inbred synthetic White Leghorn

An experiment was conducted on inbred progeny of Synthetic White Leghorn chicken to confirm the inheritance of IGF-II gene polymorphism and its effect and association with feed consumption and egg production. Parent Synthetic White Leghorn population was categorized into four different groups viz. High feed consumption and High egg production (HH), Low feed consumption and High egg production (LH), High feed consumption and Low egg production (HL), Low feed consumption and Low egg production (LL) to find out the effect of IGF-II gene polymorphism on feed consumption and egg production. This population was further propagated by sib mating to produce the next generation inbred progeny. These inbred progenies were identified according to their dam's group viz. HH, LH, HL and LL. A total of 124 inbred Synthetic White Leghorn chicks were generated and reared in deep litter system under standard feeding, managemental and health care practices. At 16th week of age, 40 females and 40 males were housed in individual California cage system. Various important economic traits were recorded on individual birds. Genomic DNA was extracted from these 80 inbred birds. Chicken gene specific primers were used for amplification of IGF-II gene, which was digested with Hin I-II for RFLP analysis. Polymorphic pattern were found in IGF-II gene and were compared from their parental generation. Gene (A and B) and Genotypic frequencies of AA, BB and AB genotypes were estimated for IGF-II gene. In IGF-II gene, HH group had significantly (P < 0.05) higher TEN64 as compared to other groups in male inbred (225.20) and in parental generation (256.90) and significantly (P < 0.05) higher EN51–60 as compared to other groups in both male (47.67) and female (49.71) inbred and in parental generation (62.10). In IGF-II gene, HH and HL groups had significantly (P < 0.05) higher DFC51–60 in female inbred progeny {(110.56) and (110.54), respectively} and in parental generation {(134.45) and (129.45), respectively} as compared to LH and LL groups. The present study revealed the strong association of different RFLP patterns with various economic traits. Similar type of results in both parental generation and inbred progeny also confirm the inheritance of IGF-II gene polymorphism and its effect and association with feed consumption and egg production.