Document Type : Original Article


Department of Animal Science, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran


This experiment was aimed to study the association between the DGAT1 K232A polymorphism and milk production traits and somatic cell score (SCS) in Iranian Holstein dairy cows. The records of 408 animals from five dairy herds were randomly identified and then genomic DNA was extracted from blood using the modified-salting method described by Miller. RFLP-PCR was performed to obtain all the polymorphisms and two alleles, K and A were observed with frequency of 0.37 and 0.63. Genotypic frequencies of AA, KA and KK were 0.3578, 0.5515 and 0.0907, respectively. The relationship between DGAT1 K232A and milk traits and somatic cell score in the first lactation was studied. The results showed significant difference (p≤0.05) between the genotypes on milk production, fat percent but not for protein percent and SCS. According to this research, the DGAT1 K232A polymorphism can be considered for increasing milk performance traits in Holstein dairy cows in the proximal region of bovine chromosome 14.


 Ali A.K.A., Shook G.E. (1980). An optimum transformation for somatic cell
concentration in milk. Dairy Sci., 63:48
 Asadollahpour N.H., Ansari Mahyari S., Edriss M.A., Pirzad M., Boroushak A. (2013). Polymorphism of SCD1 and DGAT1 gene in Isfahan Holstein cows. Adv Biol Biom Res., 1(7): 783-788.
 Farnir F., Grsart B., Coppieters W., Riquet J., Berzi P., Cambisano N., Karim L, Mni M., Moisio S., Simon P., Wagenaar D., Vilkki J., Georges M. (2002). Simultaneous mining of linkage and linkage disequilibrium to fine map
quantitative trait loci in outbred half-sib pedigrees: revisting the location of a quantitative trait locus with major effect on milk production on bovine chromosome 14. Genetics., 161: 275-287.
 Grisart B.(a), Coppieters W., Farnir F., Karim L., Ford C., Berzi P., Cambisano N., Mni M., Reid S., Simon P., Spelman R., Georges M., Snell R.(2002). Positional candidate cloning of a QTL in dairy cattle: Identification of a missense mutation in the bovine DGAT1 gene with major effect on milk yield and composition. Genome Res., 12: 222-231.
 Grisart B.(b), Farnir F., Karim L., Cambisano N., Kim J.J., Kvasz A., Mni M., Simon P., Frere J.M., Coppieters W. (2004). Genetic and functional confirmation of the causality of the DGAT1 K232A quantitative trait
nucleotide in affecting milk yield and composition. Proc Natl Acad Sci., 101: 2398-2403.
 Jamrozik J., Bohmanova J., Schaeffer L.R. (2010). Relationships between milk yield and somatic cell score in Canadian Holsteins from simultaneous and recursive random regression models. Dairy Sci., 93: 1216–1233.
 Jensen R.G. (2002). The composition of bovine milk lipids: January 1995 to December 2000. Dairy Sci., 85: 295-350.
 Jones, G.M., Pearson R.E., Clabaugh G. A., Heald C.W. (19845). Relationships between somatic cell counts and milk production. Dairy Sci., 67:1823-1831.
 Kaupe B., Winter A., Fries R., Erhardt G. (2004). DGAT1 polymorphism in Bosindicus and Bostaursus cattle breeds. Dairy Res., 71: 182-187.
 Kaupe B., Brandt H., Prinzenberg E.M., Erhardt G. (2007). Joint analysis of the influence of CYP11B1 and DGAT1 genetic variation on milk production, somatic cell score, conformation, reproduction, and productive lifespan in
German Holstein cattle. Anim Sci., 85: 11–21.
 Meredith B.K., Kearney F.J., Finlay E.K., Bradley D.G., Fahey A.G., Berry D.P., Lynn D.J. (2012). Genome-wide associations for milk production and somatic cell score in Holstein-Friesian cattle in Ireland. BMC Genetics., 13:21.
 Miller S.A., Dykes D.D., Polesky H.F. (1988). A simple salting-out procedure for extracting DNA from human nucleated cells. Nucl Acids Res., 16: 1215-1219.
 Naslud j., Fikse W.F., Pielberg G.R., Lund A. (2008). Frequency and Effect of the Bovineacyl-CoA: diacylglycerol acyltransferase1 (DGAT1) K232A Polymorphism in Swedish Dairy cattle. Dairy Sci., 91: p. 2127-2134
 Nei M. (1977). F-statistics and analysis of gene diversity in subdivided
populations. Ann Hum Genet., 41: 225-233.
 Ripoli M.V., Corva P., Giovambattita G. (2006). Analysis of a polymorphism
in the DGAT1 gene in 14 cattle breeds through PCR-SSCP methods. Res Veteri Sci 80: 287-290.
 SAS (Statistical Analysis Systems), 1997 – SAS-STAT User’s Guide, SAS
Inst. Inc. Cary. NC. Watson C. J, Neoh k. (2008). The Stat family of transcription factors have diverse roles in mammary gland development. Semin Cell Dev Biol., 19: 401-6.
 Smith S.J., Cases S., Jensen D. R, Chen H.C, Sande E., Tow B.,Sanan D.A., Raber J., Eckel R.H., Farese R.V. (2000). Obesity resistance and multiple mechanisms of triglyceride synthesis in mice lacking Dgat. In Nature
Genetics., 25: 87–90.
 Strzałkowska N., Siadkowska E., Słoniewski K., Krzyżewski J., Zwierzchowski L. (2005). Effect of the DGAT1 gene polymorphism on milk production traits in Black-and-White (Friesian) cows. Anim Sci., 3: 189-197.
 Vinicius M., Sonstegard T., Thallman R., Connor E., Schnabel R., Tassell C. (2010). Characterization of DGAT1 allelic effects in a sample of North American Holstein cattle. Anim Biotechnology., 21: 88–99.
 Winter A., Kramer W., Werner F.A.O., Kollers S., Kata S., Durstewitz G., Buitkamp J., Womack J.E., Thaller G., Fries R. (2002). Association of a lysine- 232/alanine polymorphism in a bovine gene encoding acyl- CoA:
diacylglycerolacyltransferase (DGAT1) with variation at a quantitative trait locus for milk fat content. Proc. Natl Acad Sci., 99: 9300-9305.