Fertility, represented by calving interval, has been included in the genetic evaluation of Icelandic cattle since 1993. In spite of this an unfavourable genetic trend is seen and, recent implementation of test-day models for the genetic evaluation of milk production has changed the premise of using calving interval to represent fertility. The aim of this study was to estimate genetic parameters and genetic trends of different female fertility traits in Icelandic dairy cattle and suggest new traits for the genetic evaluation. Insemination records for the first three lactations and the heifer period of 52,951 Icelandic cows were used to analyse the traits: conception rate at first insemination (CR), number of inseminations per service period (AIS), interval first to last insemination (IFL), interval calving to first insemination (ICF), interval calving to last insemination (ICL) and calving interval (CI). Correlations between fertility and production traits were also estimated. Five different linear animal models were used to estimate (co)variance components. Breeding values were compared, and genetic trends of fertility traits were investigated. Estimated heritabilities for the fertility traits were low, ranging from 0.01 (IFL) to 0.08 (ICF). Genetic correlations between heifer and cow performances within traits ranged from 0.23 to 0.81. Between lactations within traits, the genetic correlations ranged from 0.36 to 1.00. Genetic correlations between different heifer traits were strong, and between different cow fertility traits they ranged from weak (-0.17) to very strong (0.97). Genetic correlations between the fertility and production traits were generally unfavourable, but more pronouncedly so for AIS, IFL, ICL and CI than for ICF and CR. Estimated genetic trends seemed unfavourable for the traits AIS, IFL and CI and favourable for ICF and ICL. In a revised genetic evaluation for fertility in Icelandic cattle, the traits ICF and IFL should be included to represent cow fertility, and CR to represent heifer fertility.

自 1993 年以来，以产犊间隔为代表的生育力已被纳入冰岛牛的遗传评估。尽管如此，仍看到不利的遗传趋势，并且最近实施的产奶遗传评估测试日模型改变了前提使用产犊间隔来表示生育能力。本研究的目的是估计冰岛奶牛不同雌性生育性状的遗传参数和遗传趋势，并为遗传评估提出新的性状。前三个泌乳期和 52,951 头冰岛奶牛的授精记录用于分析以下特征：首次授精时的受孕率 (CR)、每个服务期的授精次数 (AIS)、首次授精至末次授精的间隔 (IFL)、间隔产犊到第一次授精（ICF），产犊间隔至最后一次授精 (ICL) 和产犊间隔 (CI)。还估计了生育力和生产性状之间的相关性。五种不同的线性动物模型用于估计（协）方差分量。比较育种值，调查生育性状的遗传趋势。生育性状的估计遗传力较低，范围从 0.01 (IFL) 到 0.08 (ICF)。小母牛和奶牛性能之间的遗传相关性在 0.23 到 0.81 之间。在性状内的哺乳期之间，遗传相关性介于 0.36 到 1.00 之间。不同小母牛性状之间的遗传相关性很强，不同奶牛生育性状之间的遗传相关性从弱（-0.17）到非常强（0.97）不等。生育力和生产性状之间的遗传相关性普遍不利，但对于 AIS、IFL、ICL 和 CI，比 ICF 和 CR 更明显。估计的遗传趋势似乎对 AIS、IFL 和 CI 性状不利，而对 ICF 和 ICL 有利。在修订后的冰岛牛生育力遗传评估中，应包括 ICF 和 IFL 性状来代表母牛的生育力，而 CR 代表小母牛的生育力。