ANALISIS KORELASI GENETIK ANTARA BOBOT LAHIR, BOBOT SAPIH, DAN BOBOT YEARLING PADA SAPI BRAHMAN CROSS (BX) Genetic Correlation Analysis between Birth Weight, Weaning Weight, and Yearling Weight of Brahman Cross (BX) Cattle

Abstract

Genetic correlations between productive traits have important role in beef cattle selection.  This study aimed to estimate genetic correlation between birth, weaning, and yearling weight of Brahman Cross (BX) cattle. The experiment was carried out at PT Lembu Jantan Perkasa (PT LJP) Serang, Banten. There were 31 heads of BX offspring, which were obtained from 3 sire and 31 dams. The average birth weight was 23.1 ± 2.21 Kg, weaning weight 73.5 ± 13.02 Kg, and yearling weight was 257.9 ± 61.15 Kg. Genetic correlation was analyzed by covariance analysis. The genetic correlation between birth weight and weaning weight was 0.12, birth weight and yearling weight 0.31, and weaning weight and yearling weight was 0.47. The results indicated that the selection based on birth and weaning weight could be conducted in order to increase yearling weight in BX cattle, since these variables have high and positive genetic correlation to yearling weight.

ABSTRAK
Korelasi genetik diantara sifat-sifat produksi memiliki peranan penting dalam kegiatan seleksi sapi pedaging. Penelitian ini bertujuan untuk menduga nilai korelasi genetik antara bobot lahir, sapih, dan bobot yearling pada Sapi Brahman Cross (BX). Penelitian dilaksanakan di PT Lembu Jantan Perkasa, Serang Banten. Materi penelitian meliputi 31 ekor sapi BX yang berasal dari 3 pejantan dan 31 ekor induk betina. Rataan bobot lahir yang didapatkan sebesar 23,1 ± 2,21 Kg, bobot sapih sebesar 73,5 ± 13,02 Kg, dan bobot yearling sebesar 257,9 ± 61,15 Kg. Korelasi genetik dianalisis dengan analisis peragam antar saudara tiri. Nilai korelasi genetik antara bobot lahir dengan sapih sebesar 0,12, bobot lahir dengan bobot yearling sebesar 0,31, sedangkan bobot sapih dan bobot yearling sebesar 0,47. Hasil menunjukan bahwa pelaksanaan seleksi dapat dilakukan berdasarkan bobot lahir dan bobot sapih dalam rangka peningkatan peforma sapi BX, dikarenakan kedua peubah memiliki korelasi genetik yang positif dan tinggi terhadap bobot yearling.