As long as large-scale recording of expensive-to-measure and labor-consuming traits, such as dry matter intake (DMI) and CH₄ production (CH₄P), continues to be challenging in practical conditions, alternative traits that are already routinely recorded in dairy herds should be investigated. An ideal indicator trait must, in addition to expressing genetic variation, have a strong correlation with the trait of interest. Our aim was to estimate individual level and phenotypic correlations between rumination time (RT), CH₄P, and DMI to determine if RT could be used as an indicator trait for CH₄P and DMI. Data from 343 Danish Holstein cows were collected at the Danish Cattle Research Centre for a period of approximately 3 yr. The data set consisted of 14,890 records for DMI, 15,835 for RT, and 6,693 for CH₄P. Data were divided in primiparous cows only (PC) and all cows (MC), and then divided in lactation stage (early, mid, late, and whole lactation) to analyze the changes over lactation. Linear mixed models, including an animal effect but no pedigree, were used to estimate the correlations among traits. Phenotypic and individual level correlations between RT and both CH₄P and DMI were close to zero, regardless of lactation stage and data set (PC or MC). However, CH₄P and DMI were highly correlated, both across lactation stages and data sets. In conclusion, RT is unsuitable to be used as an indicator trait for either CH₄P or DMI. Our study failed to validate RT as a useful indicator trait for both CH₄P and DMI, but more studies with novel phenotypes can offer different approaches to select and incorporate important yet difficult to record traits into breeding goals and selection indexes.

只要大规模记录昂贵的测量和劳动消耗性状，例如干物质摄入量（DMI）和CH ₄产生量（CH ₄ P），在实际条件下仍然是具有挑战性的，已经存在的替代性状常规记录在奶牛群中的应进行调查。理想的指标性状除了表达遗传变异外，还必须与目标性状有很强的相关性。我们的目的是估计反刍时间（RT），CH ₄ P和DMI之间的个体水平和表型相关性，以确定RT是否可以用作CH ₄的指标性状。P和DMI。从丹麦牛研究中心收集了大约3年的343头丹麦荷斯坦奶牛的数据。数据集包括DMI的14,890条记录，RT的15,835条记录和CH ₄ P的6,693条记录。数据分为仅初生奶牛（PC）和所有奶牛（MC），然后按泌乳阶段（早，中，晚）划分和整个哺乳期）来分析哺乳期的变化。使用线性混合模型（包括动物效应但没有谱系）来估计性状之间的相关性。RT与CH ₄ P和DMI两者之间的表型和个体水平相关性接近于零，而与哺乳期和数据集（PC或MC）无关。但是，CH ₄在哺乳阶段和数据集之间，P和DMI高度相关。总之，RT不适合用作CH ₄ P或DMI的指标性状。我们的研究未能将RT验证为CH ₄ P和DMI的有用指标性状，但是更多有关新表型的研究可以提供不同的方法来选择重要的但难以记录的性状并将其纳入育种目标和选择指数。