التشكل الوراثي لجين FASN وعلاقته بإنتاج الحليب و مكوناته في الأبقار المحلية و الفريزيان

الملخص EN

Atotal of 60 cows from Freisian and local Iraq breed (30 each) were used for aperiod of 1/12/ 2014 to 30 /3 /2015.

Cows were from local breeders within Thi –Qar province.

Samples were collected from each animal once a week hrough study period.

After measuring milk yield, asmples of 50 ml were taken to estimate fat , protein and some other milk composition as well as fatty acid composition were estimated from extracted fat Besides that blood samples from each animal were taken to extract a DNA.

FASN gene has been amplified and were gene has been amplified and were identified.Genotypes were AA,AG and GG with a frequency of 0.13, 0.54 and 0.33 respectively for Freisian breed and 0.47,0.33 and 0.16 of Local breed.

A and G alleles frequencies were 0.40 and 0.60 of Freisian breed and 0.65 and 0.35 of local breed respectively, the two population were at aqulibirium .

The two breeds showed similar expected heterozygosity (48.81 and 46 .27% respectirely).

AA and GG genotypes excceded the genotype AG by daily and total milk yield of Freisian breed.

They produced 2968 and 2304.80 kg total milk yield respectively.AG gene produced only 2645.54 kg.

AA genotype of Freisian produced significantly higher fat and protein (97.10 and 100.05 kg respectively).As well as AA and AG genotypes produced singnificantly higher fat% (3.27% and 3.29% respectively) in comparison with 3.17% of GG genotypes.

AG genotype produced highest protein% (3.4170)in comparison with other genotypes.AA genotypes of local breed exceeded other genotype in producing daily and total milk yield,fat and protein.

On contrary, GG genotype yielded higher fat (4.2%) in comparison with that of other genotypes.

AA and GG genotypes have got highest level of protein (3.25 and 3.30% respechvely) in comparison with 3.20% AA genotype.Only AG and GG of local breed showed fat/protein percent (1.23 and 1.27 respectively) within the standard range.