{"references": ["Amonrat, M., L. Boonek, and N. Rungsakinnin. 2011. The Effect of\nbeta and kappa casein genes on milk yield and milk composition in\ndifferent percentages of holstein in crossbred dairy cattle. Anmal Sci. J.\n(to be published).", "Banos, G., J.A. Woolliams, B.W. Woodward, A.B. Forbes, and M.P.\nCoffey. 2008. Impact of single nucleotide polymorphisms in leptin,\nleptin receptor, growth hormone receptor, and diacylglycerol\nacyltransferase (DGAT1) Gene loci on milk production, feed, and body\nenergy traits of UK dairy cows. J. Dairy Sci. 91: 3190 - 3200.", "Bobe, G., D.C. Beitz, A.E. Freeman, and G.L. Linderg. 1999. Effect of\nmilk protein genotypes on milk composition and its genetic parameter\nestimates. J. Dairy Sci. 82, 2797-2804.", "Braunschweig, M., C. Hagger, G. Stanzinger, and Z. Puhan. 2000.\nAssociations between casein haplotypes and milk production traits of\nSwiss Brown cattle. J Dairy Sci. 83, 1387 - 1395.", "Comin, A., M. Cassandro, S. Chessa, M. Ojala, R. Dal Zotto, M. De\nMarchi, P. Carnier, and L. Gallo. 2008. Effect of composite \u03b2 and\n\u256c\u2551 casein genotype on milk coagulation, quality and yield traits in\nItalian Holstein cows. J. Dairy Sci. 91, 4022-4027.", "Grisart, B., W. Coppieters, F. Farnir, L. Karim, C. Ford, P. Berzi, N.\nCambisano, M. Mni, S. Reid, P. Simon, R. Spelman, M. Georges, and R.\nSnell. 2002. Positional candidate cloning of a QTL in dairy cattle:\nidentification of a missense mutation in the bovine DGAT1 gene with\nmajor effect on milk yield and composition. Genome Research, 12(2),\n222-231.", "Ikonen, T., M. Ojala, and O. Ruottinen, 1999. Associations between\nmilk protein polymorphism and first lactation milk production traits in\nFinnish Ayrshire cows. J. Dairy Sci. 82, 1026-1033.", "Jann, O. C., E. M. Ibeagha-Awemu, Ozbeyaz, C. Zaragoza, P. Williams,\nJ. L. Ajmone-Marsan, P. Lenstra, J. A. Moazami-Goudarzi, and K.\nErardt. 2004. Geographic distribution of haplotype diversity at the\nbovine casein locus. Genet. Sel. Evol. 36, 243-257.", "Khatib, H., W. Huang, X. Wang, A.H. Tran, A.B. Bindrim, V.\nSchutzkus, R.L. Monson, and B.S. Yandell. 2009. Single gene and gene\ninteraction effects on fertilization and embryonic survival rates in cattle.\nJ. Dairy Sci. 92: 2238 - 2247.\n[10] Koczan D., G. Hobom, and H. -M. Seyfert. 1991. Genomic organization\nof the bovine alpha-s1 casein gene. Nucl. Acids Res. 19, 5591-5596.\n[11] Kuehn, C., C. Edel, R. Weikard, G. Thaller. 2007. Dominance and\nparent-of-origin effects of coding and non-coding alleles at the\nacylCoA-diacylglycerol-acyltransferase (DGAT1) gene on milk\nproduction traits in German Holstein cows. BMC Genetics. 8, 62-70.\n[12] Mercier, J. C., and J. L. Viloite. 1993. Structure and function of milk\nprotein genes. J. Dairy Sci. 76, 3079-3098.\n[13] Naslund, J., W.F. Fikse, G.R. Pielberg, A. Lunden. 2008. Frequency and\neffect of the bovine acyl -CoA:diacylglycerol acyltransferase 1\n(DGAT1) K232A polymorphism in Swedish dairy cattle. Journal Dairy\nScience, 91 (5), 2127-2134.\n[14] Sanders, K., J. Bennewitz, N. Reinsch, G. Thaller, E-M. Prinzenberg, C.\nKuhn, and E .Kalm. 2006. Characterization of the DGAT1 Mutations\nand the CSN1S1 Promoter in the German Angeln Dairy Cattle\nPopulation. J. Dairy Sci. 89: 3164 - 3174.\n[15] Signorelli, F, L. Orr\u251c\u2563, F. Napolitano, G.D. Matteis, M.C. Scat\u251c\u00e1, G.\nCatillo, C. Marchitelli, B. Moioli. 2009. Exploringpolymorphisms and\neffects on milk traits of the DGAT1, SCD1 and GHR genes in four cattle\nbreeds. Livestock Science, 125, 74-79.\n[16] Sun, D., J. Jia, Y. Ma, Y. Zhang, Y. Wang, Y. Yu, and Y. Zhang. 2009\nEffects of DGAT1 and GHR on milk yield and milk composition in the\nChinese dairy population. Animal Genetics, 40, 997-1000.\n[17] Winter, A., W. Kramer, F. Werner, S. Kollers, S. Kata, G. Durstewits,\nand J. Buitkamp, J.E. Womack, G. Thaller, and R. Fries. 2002.\nAssociation of a lysine-232/alanine polymorphism in a bovine gene\nencoding diacylglycerol acyltransferase (DGAT) with variation at a\nquantitative trait locus for on milk fat content in cattle. Proceedings of\nthe National Academy of Sciences, 99, 9300-9305."]}

The objective was to determine the single gene and interaction effect of composite genotype of beta-kappa casein and DGAT1 gene on milk yield (MY) and milk composition, content of milk fat (%FAT), milk protein (%PRO), solid not fat (%SNF), and total solid (%TS) in crossbred Holstein cows. Two hundred and thirty- one cows were genotyped with PCR-RFLP for DGAT1 and composite genotype data of beta-kappa casein from previous work were used. Two model, (1), and (2), was used to estimate single gene effect, and interaction effect on the traits, respectively. The significance of interaction effects on all traits were detected. Most traits have consistent pattern of significant when model (1), and (2) were compared, except the effect of composite genotype of betakappa casein on %FAT, and the effect of DGAT1 on MY, which the significant difference was detected in only model (1).The results suggested that when the optimum of all traits was necessary, interaction effect should be concerned.