Abstract
BACKGROUND: Chinese Holstein is a dairy cattle breed developed through crossbreeding and long-term selection. The Beijing Holstein represents a distinct population within the Chinese Holstein breed, specifically bred in the Beijing region. OBJECTIVES: This study aimed to estimate the genetic parameters for six economic traits in Beijing Holstein cows. METHODS: Data from 5409 Beijing Holstein cows across 13 dairy farms were analysed by MTDFREML and SAS software. The linear univariate and bivariate animal model analyses were employed to estimate heritabilities and genetic correlations, respectively. RESULTS: Heritabilities of milk yield in 305 days (d), fat percentage, protein percentage, somatic cell score (SCS), lactose percentage and dry matter percentage were 0.08, 0.17, 0.20, 0.10, 0.16 and 0.26, respectively. Most genetic correlations aligned in direction and magnitude with their phenotypic correlations. Notably, dry matter percentage exhibited strong positive genetic correlations with fat percentage (0.96), protein percentage (0.74) and lactose percentage (0.70). The genetic correlations were moderately significant negative between dry matter percentage and milk yield in 305 d (-0.39), between SCS and dry matter percentage (-0.26), between SCS and lactose percentage (-0.30), and between SCS and fat percentage (-0.38). CONCLUSIONS: On the basis of the genetic parameters and their economic significance, the milk yield in 305 d, fat percentage, protein percentage and SCS would be selected as breeding goal traits with different direction and extent of weight. A balanced breeding approach targeting these traits is essential to enhance overall production performance. This study provides foundational data for evaluating the production potential of Beijing Holstein cows and supports informed breeding decisions.