The rennet-induced coagulation ability of milk is important in cheese production. For Swedish Red Dairy Cattle (RDC), this ability is reduced because of a high prevalence of noncoagulating (NC) milk. In this study, we simultaneously combined genetic parameters for NC milk, milk coagulation properties, milk composition, physical traits, and milk protein composition. Our aim was to estimate heritability and genetic and phenotypic correlations for NC milk and 24 traits (milk coagulation properties, milk composition, physical traits, and milk protein composition). Phenotypes and ∼7,000 SNP genotypes were available for all 600 Swedish RDC. The genotypes were imputed from ∼7,000 SNP to 50,000 SNP. Variance components and genetic parameters were estimated with an animal model. In Swedish RDC, a moderate heritability estimate of 0.28 was found for NC milk. For the other 24 traits, heritability estimates ranged from 0.12 to 0.77 (standard errors from 0.08 to 0.18). A total of 300 phenotypic and genetic correlations were estimated. For phenotypic and genetic correlations, 172 and 95 were significant, respectively. In general, most traits showing significant genetic correlations also showed significant phenotypic correlations. In this study, phenotypic and genetic correlations with NC milk suggest that many correlations between traits exist, making it difficult to predict the real consequences on the composition of milk, if selective breeding is applied on NC milk. We speculate that some of these consequences may lead to changes in the composition of milk, most likely affecting its physical and organoleptic properties. However, our results suggest that κ-casein could be used as an indicator trait to predict the occurrence of NC milk at the herd level.

凝乳酶诱导的牛奶的凝结能力在奶酪生产中很重要。对于瑞典红奶牛（RDC），由于非凝结（NC）奶的高流行，这种能力降低了。在这项研究中，我们同时结合了NC牛奶的遗传参数，牛奶凝结特性，牛奶成分，物理特性和牛奶蛋白质成分。我们的目的是评估NC牛奶和24个性状（牛奶凝结特性，牛奶成分，物理特性和牛奶蛋白质成分）的遗传力以及遗传和表型相关性。表型和约7,000个SNP基因型可用于全部600个瑞典RDC。将基因型推算为约7,000 SNP至50,000 SNP。用动物模型估计方差成分和遗传参数。在瑞典的RDC中，发现NC牛奶的遗传度估计为0.28。对于其他24个性状，遗传力估计值范围为0.12至0.77（标准误为0.08至0.18）。总共估计了300个表型和遗传相关性。对于表型和遗传相关性，分别为172和95。通常，大多数表现出显着遗传相关性状也表现出显着的表型相关性。在这项研究中，与NC牛奶的表型和遗传相关性表明，性状之间存在许多相关性，因此，如果对NC牛奶进行选择性育种，则很难预测对牛奶成分的实际影响。我们推测其中一些后果可能导致牛奶成分发生变化，最有可能影响其物理和感官特性。然而，