Genetic Polymorphisms of Fabp4 Gene and Their Association with Milk Traits in Barki Ewes الأنماط الجينيه لجين FABP4 وعلاقتها بصفات اللبن في نعاج البرقي

The fatty acid binding proteins (FABPs) were recognized in cattle as promising candidate genes for various economic traits in general and particularly milk. Nevertheless, limited information is available about the contribution of these genes in sheep. Alongside, there is an increasing interest for sheep dairy production worldwide. Single strand conformation polymorphism technique was used to investigate the polymorphisms in FABP4 gene in Barki sheep breed.  Three genetic variants (named A, B and C) were identified with allelic frequencies 34.55%, 31.33%, and 34.12% for the corresponding alleles, respectively. Significant associations were found between the FABP4 genotypes and fat percentage (FP; P=0.027), lactose percentage (LP, P=0.015) and total solid percentage (TSP; P=0.001) in milk. However, no significant association (P>0.05) was reported for milk yield per day (DMY) or percentage of the protein (PP). Absence of allele A significantly decreased FP (-1.28%; P=0.04), LP (-1.67%; P=0.04), PP (-1.36; P=0.01), and TSP (-6.66%; P=0.01), while allele C tended to increase TSP (+4.82%; P=0.06). Worthwhile, ewes with the BC geno­type produced more DMY (363.48±27.74g/day; P=0.26) with higher TSP (22.99±1.27%) and LP (7.88±0.33%) compared to ewes with other genotypes. Likewise, ewes that carry AC genotypes tended to produce milk with higher FP (5.69±0.40%; P=0.025) and PP (6.70±0.40%; P=0.27). Results showed that the DMY, FP, and TSP significantly influenced by the age and parity of ewe. This study presented a valuable information concerning the FABP4 gene polymorphisms as potential candidate gene underlying genetic markers for milk production in Barki sheep.