Impact of BLG gene polymorphism on some ovine production traits reared in middle part of Iraq

Milk composition and milk yield, considered as a vital role in production, effected by many genes like BLG gene. The current study was aimed to estimate the impact of BLG gene genotyping on production of Iraqi Awassi sheep from 62 ewes via Polymerase Chain Reaction (PCR) then Restriction Fragment Length Polymorphisms (RFLP) method. The high variance in fat (14.24%) but relatively less in lactose (7.66%), protein (7.20%) and SNF (7.91%) that is referred to the possibility of selection of flocks depending on fat percentage. BLG gene was successfully amplified using specific primer. The calculation of allele frequency was done for all samples under study. RFLP with RsaI restriction enzyme was revealed three patterns including AA, AB and BB genotypes. AA genotype was appeared at 350bp, AB within 350bp and 450 bp respectively, and BB at 450bp. The dominated genotype was AB (37%) followed by BB (34%) and then AA (29%) with dominant A allele (0.52) than B allele. The deviations probability using Hardy-Weinberg equilibrium (HWE) of BLG gene was based on chi-square (χ2) test and confirms that all frequencies within Iraqi Awassi population were in HWE (p ˂ 0.05). Current study showed that the higher rate of fat yield was related to AA genotype (9.39%), while the lowest to BB (7.84%). The present findings suggested that the significant differences are related between AB genotype (6.71%) and lactose percentage in comparison to another genotypes; AA (5.84%) and BB (6.37%). The density (g cm^-2) of milk can be used to determine the quality of milk for all animal breeds. In the present study, the high milk density was related to AB genotyping (1.049%), whereas the low milk density to AA genotype (1.021%). The BLG gene can be incorporated in Iraqi Awassi breeding programs to enhance the development and improve milk components.