ABSTRAK Penelitian ini bertujuan untuk menganalisis hubungan polimorfisme gen hormon pertumbuhan (leu/val) dan produksi susu pada sapi Friesian Holstein. Sampel penelitian berasal dari 62 ekor sapi yang diambil dari dua kelompok sapi Friesian Holstein (dari New Zealand=19 ekor and Australia=43 ekor). Polymerase Chain Reaction (PCR) yang dilanjutkan dengan Restriction Fragment Length Polymorphism (RFLP) menggunakan enzim restriksi AluI untuk menentukan genotip sapi. Genotip ditentukan

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... target gen GH 211 bp yang terletak pada intron 4 dan exon 5 dari gen hormon pertumbuhan. Genotypes Leu/Leu (LL) pada kedua grup menunjukkan frekuensi yang lebih tinggi dibandingkan dengan genotip Leu/Val (LV). Sapi Friesian Holstein dari New Zealand memperlihatkan genotip LL dan LV sebesar 84% dan 16%. Sapi Friesian Holstein dari Australia memiliki genotip LL dan LV sebesar 79% and 21%. Hubungan antara polimorfisme Leu/Val pada gen hormon pertumbuhan terhadap produksi susu, kadar lemak dan protein tidak menunjukkan pengaruh yang nyata pada kedua grup. Berdasarkan pengelompokan asal sapi, hasil penelitian menunjukkan perbedaan yang nyata pada kadar lemak dan protein susu. Kadar lemak dan protein susu pada sapi FH yang diimpor dari Australia lebih tinggi dibandingkan dengan kadar lemak dan protein susu pada sapi FH yang diimpor dari New Zealand. Kata kunci: Friesian Holstein import, gen hormon pertumbuhan, produksi susu, kadar lemak dan protein ABSTRACT The aim of the research was to determine the associations between polymorphism of the bovine growth hormone (GH) gene (Leu/Val) and milk production of Friesian Holstein Cattle. A total of 62 cows which consist of two Friesian Holstein cattle groups (from New Zealand=19 heads and Australia=43 heads) were used for the research. We performed the Polymerase Chain Reaction and followed by Restriction Fragment Length Polymorphism using AluI restriction enzyme. The genotype was observed base on the target gene GH 211 bp in the part of intron 4 and exon 5 of growth hormone gene. The frequencies of genotypes LL were found higher than genotype LV in both groups. Friesian Holstein cattle from New Zealand showed the genotype LL and LV as 84% and 16%, respectively. Friesian Holstein cattle from Australia show the genotype LL and LV as 79% and 21%, respectively. The association between Leu/Val polymorphism on milk production, fat and protein content in both groups did not show the significant effect. Base on two groups of the origin of cattle, the result showed the significant different on fat and protein content of milk. Fat and protein contents of milk were higher in breed of FH imported from Australia compared to those in breed of FH imported from New Zailand.