产奶性状是荷斯坦牛的重要经济性状，对产奶性状进行遗传参数估计可为后续育种研究奠定良好基础。该研究整合了来自河北和宁夏两个地区13个牧场的60 560头荷斯坦牛在2009-2023年间的567 969条DHI测定记录以及系谱记录，基于随机回归测定日模型进行产奶性状的遗传参数估计。结果表明：第1和第2胎次相应性状的遗传力分别为：产奶量0.24和0.15，乳蛋白量0.19和0.13，乳脂量0.11和0.07，体细胞评分均为0.02。产奶量、乳蛋白量和乳脂量之间呈表型和遗传正相关，而体细胞评分和前3个性状之间大多呈表型和遗传负相关。该结果可为荷斯坦牛的群体选育提供重要参考。

Milk production traits are crucial economic traits in Holstein cattle, and estimating genetic parameters for milk production traits lays a solid foundation for subsequent breeding research. This study integrated 567 969 DHI test-day records and pedigree data from 60 560 Holstein cows across 13 farms in Hebei and Ningxia provinces between 2009 and 2023. Genetic parameter estimation for milk production traits was conducted using a random regression test-day model. The results indicated heritability estimation for each trait in the first and second parity were as follows: Daily Milk Yield - 0.24 and 0.15; Milk Protein Yield - 0.19 and 0.13; Milk Fat Yield - 0.11 and 0.07; Somatic Cell Score - 0.02 for both parities. Moreover, there were positive phenotypic and genetic correlations among Daily Milk Yield, Milk Protein Yield, and Milk Fat Yield, while mostly negative phenotypic and genetic correlations were observed between Somatic Cell Score and the aforementioned three traits. These findings provide important insights for population breeding of Holstein cattle.