Genetic parameters of milk yield and reproductive performance traits in Holstein-Friesian dairy cattle

Abstract

Understanding the genetic structure of economically important traits in dairy cattle is a fundamen-tal requirement before designing any effective breeding program. This study was conducted to estimate genetic parameters, including heritability and genetic and phenotypic correlations, for 305-day Milk Production (P305), Calving Interval (CI), Dry Period (DP), Peak Yield (PY), and Days to Peak Yield (DPY) in Holstein-Friesian dairy cattle in Indonesia. The data were collected from 2017 to 2024 and analyzed using the restricted maximum likelihood (REML) procedure. The overall least-squares means were 8,178.04 ± 23.08 kg for P305, 395.37 ± 1.21 days for CI, 66.60 ± 0.53 days for DP, 40.60 ± 0.12 kg for PY, and 78.00 ± 0.58 days for DPY. Heritability estimates were moderate to high for P305 (0.40 ± 0.02) and PY (0.48 ± 0.02), low for CI (0.18 ± 0.02) and DP (0.10 ± 0.02), and very low for DPY (0.03 ± 0.01). A strong positive genetic correlation was found between P305 and PY (0.99). These re-sults provide useful baseline information for developing a National Dairy Cattle Improvement Program in Indonesia's tropical management conditions.