Identifikasi Keragaman Gen Hormon Pertumbuhan dan Reseptornya serta Hubungannya dengan Produksi Susu Kumulatif Parsial pada Sapi Friesian Holstein di Sentra Produksi Jawa Barat

Abstract

Perbaikan genetik sapi perah dapat dilakukan melalui seleksi keunggulan pada gen yang berasosiasi kuat dengan sifat produksi susu. Gen hormon pertumbuhan diketahui berperan penting dalam regulator pertumbuhan ternak dan perkembangan kelenjar mammari. Penelitian ini bertujuan untuk mengidentifikasi keragaman genetik gen Growth Hormone (GH) dan Growth Hormone Receptor (GHR) sapi Friesian Holstein (FH) serta menganalisis hubungan antara keragaman genotipe kedua gen dengan produksi susu kumulatif parsial.

Growth hormone gene has a critical role in the regulation of lactation, mammary gland development and growth process through its interaction with its specific receptor. Growth Hormone (GH) and Growth Hormone Receptor (GHR) genes have been suggested as candidate genes for traits related to milk production. The purpose of this study was to identify genetic polymorphism of the Growth Hormone (GH) and the Growth Hormone Receptor (GHR) genes, and the association of their genetic variants with milk yield in Holstein Friesian (HF) cattle. A total of 370 HF cattle from six populations of Institute for breeding of dairy cattle Cikole station (88 samples), Pasir Kemis (96 samples), Cilumber (98 samples), Lembang Artificial Insemination Center (LAIC) (17 samples), Livestock Embryo Transfer Center (40 samples) and Singosari Artificial Insemination Center (SAIC) (32 samples) were genotyped by the Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) methods. Genotyping the GH gene with Alu1 restriction enzyme to all DNA samples produced two variant genotypes, i.e LL (89 %) and LV (11%) genotypes. The frequency of L allele was 94 % and V allele was 6%. Genotyping of GHR gene with Alu1 restriction enzymes produced three genotypes and two alleles. The frequencies of AA, AG, and GG genotypes were 58 %, 34%, and 8% respectively. The frequency of A allele was 75% and G allel was 25%. There was no association between GH and GHR polymorphism with milk production.