Deteksi Dini Kelainan Genetik Complex Vertebral Malformation dan Factor XI Deficiency pada Sapi Perah Friesian-Holstein

Abstract

Kelainan genetik merupakan salah satu kelainan pada temak yang disebabkan oleh mutasi pada material genetik. Jika ekspresi mutan mengikuti hukum dominanresesif dari Mendel, maka dalam keadaan heterozigot sifat tersebut tidak terekspresi karena tertutup oleh alel normal pasangannya. Kondisi heterozigot disebut sebagai karier yang dalam penampilannya tampak normal. Kondisi karier ini akan selalu berada dalam populasi, sebingga homozigot resesif yang merugikan dapat muncul sewaktu-waktu bila terjadi perkawinan antar individu heterozigot. Pada saat ini, beberapa pejantan unggul sapi perah Friesian-Holstein (FH) yang populer digunakan dalam inseminasi buatan serta telah menyebar ke beberapa negara pengimpor sapi perah, temyata diketahui membawa mutasi yang menyebabkan complex vertebral malformation (CVM) dan factor XI deficiency (FIID). Akibatnya, sapi perah di beberapa negara tercemar kedua kelainan genetik tersebut.

Complex vertebral malformation (CVM) and factor XI deficiency (FIID) are genetic disorders caused by autosomal recessive genes in cattle. CVM is due to mutation in SLC35A3 gene at exon 4 of chromosome BTA3 encoding for a UDP-N-acetylglucosamine transporter. The substitution of guanine by thymine at nucleotide position 559 in SLC35A3 gene will change valine by phenylalanine at position 180 (V180F). Calves affected by this mutation have numerous anatomical deformations. While FIID is due to insertion of 76 bp in a Factor XI gene at exon 12 of chromosomes 17. Calves affected by this insertion can be asymtomatic or show a number of indicator that may include prolonged bleeding after injection, production of bloody milk and anemia. The aim of this research was to develop detecting method of the genetic disorders of CVM and FllD in Holstein-Fresian cattle by polymerase chain reaction method. Genotyping of 676 Holstein-Friesian blood sample from breeding center and small-scale husbandaries were analyzed. Five of all succesfull amplified samples were detected as FI1D carriers but no CVM allele was found. As FI1D carrier, animal was in a normal performance. The F 11 D carriers were supposed coming from old population before the last decades. Eventhough Indonesian's Holstein-Fresian population lack of CVM carrier, all stakeholders need to be aware. The early warning system resulted from this research could be useful to prevent the introduction of mutated alleles in Indonesian dairy cattle population.