The objectives of this study were to estimate genetic parameters for longevity and reproductive and to evaluate their likely consequences on selection. We used calving records of 10,517 Aberdeen Angus cows, born between 1975 and 2012, with first calving in spring, from bulls with 5 or more daughters, herds with 25 or more observations, and pertaining to contemporary groups of 5 or more cows. Longevity variables were length of productive life (LPL) and stayability at 5 years (ST5); the reproductive variables were days to first calving (days1), calving success at second parity (CS2), and success of having the first three consecutive calvings (S3). CS2, S3 and ST5 were defined as binary, and days1 and LPL as continuous variables. A multi-trait, threshold-linear model was used, including contemporary group effects (herd-year of birth; days1 also included management group), age at first calving (covariate), and the genetic effect of the animal. Given the parameters, five strategies were explored to predict annual genetic progress: selection of 5% or 25% of progeny tested males, with progeny groups of 5 or 15 daughters (no selection in females), and mass selection of 75% in females (no selection in males). Annual realized genetic trends and correlated responses when selecting for ST5, CS2 or S3 were also calculated. The estimates (mean ± standard deviation a posteriori) of heritability for longevity traits were 0.08±0.03 for LPL and 0.11±0.05 for ST5; for reproductive traits, estimations were 0.08±0.02 for days1, 0.23±0.04 for S3, and 0.24±0.04 for CS2. The genetic correlation between LPL and ST5 was favourable and large (0.79); and were also favourable and large for reproductive characteristics (negative, -0.66 for days1-S3 and -0.73 for days1-CS2, and positive, +0.83 for S3-CS2). Correlations between longevity and reproduction were variable, from not different from zero (days1 with ST5 and LPL) to medium (+0.45 for ST5-S3). Realized annual genetic trends indicated small but significant favourable changes for ST5 and LPL, and unfavorable for days1, CS2 and S3. Correlated responses were, in general, also favourable, although less than the progress achieved by direct selection. There are wide possibilities for genetic improvement in these characteristics.

这项研究的目的是估计长寿和繁殖的遗传参数，并评估它们对选择的可能影响。我们使用了 10,517 头 Aberdeen Angus 母牛的产犊记录，这些母牛出生于 1975 年至 2012 年之间，在春季首次产犊，来自有 5 个或更多女儿的公牛，有 25 个或更多观察的牛群，并且与 5 个或更多母牛的当代群体有关。长寿变量是生产寿命的长度 (LPL) 和 5 年的可居住性 (ST5)；繁殖变量是第一次产犊的天数 (days1)、第二胎产犊的成功率 (CS2) 和前三胎连续产犊的成功率 (S3)。CS2、S3 和 ST5 定义为二元变量，days1 和 LPL 定义为连续变量。使用了多特征、阈值线性模型，包括当代群体效应（出生年份；天数还包括管理组）、首次产犊的年龄（协变量）和动物的遗传效应。给定参数，探索了五种策略来预测年度遗传进展：选择 5% 或 25% 的后代测试雄性，后代组为 5 或 15 个女儿（雌性未选择），以及 75% 的雌性大规模选择（男性没有选择）。还计算了选择 ST5、CS2 或 S3 时的年度实现遗传趋势和相关反应。估计值（平均值±标准差 和 75% 的女性群体选择（男性没有选择）。还计算了选择 ST5、CS2 或 S3 时的年度实现遗传趋势和相关反应。估计值（平均值±标准差 和 75% 的女性群体选择（男性没有选择）。还计算了选择 ST5、CS2 或 S3 时的年度实现遗传趋势和相关反应。估计值（平均值±标准差后验的) 长寿性状的遗传力 LPL 为 0.08±0.03，ST5 为 0.11±0.05；对于生殖性状，第 1 天的估计值为 0.08±0.02，S3 的估计值为 0.23±0.04，CS2 的估计值为 0.24±0.04。LPL与ST5的遗传相关性良好且大（0.79）；并且对生殖特征也有利且大（负，第 1-S3 天为 -0.66，第 1-CS2 天为 -0.73，S3-CS2 为阳性，+0.83）。寿命和繁殖之间的相关性是可变的，从零（ST5 和 LPL 的第 1 天）到中等（ST5-S3 为 +0.45）。已实现的年度遗传趋势表明 ST5 和 LPL 的变化很小但显着，而第 1、CS2 和 S3 天则不利。总体而言，相关的反应也是有利的，但不如直接选择取得的进展。