Unitat de Cunicultura, Institut de Recerca i Tecnologia Agroalimentàries, Torre Marimon s/n, 08140, Caldes de Montbui, Barcelona, Spain.
J Anim Sci. 2012 May;90(5):1385-97. doi: 10.2527/jas.2011-4165. Epub 2011 Nov 18.
This work aims to estimate the genetic parameters of seminal and production traits in a paternal line of rabbits selected for ADG during the fattening period. The considered traits were male libido (Lib) defined as successful mounting of an artificial vagina; presence of urine (Ur) and calcium carbonate deposits (Ca) in the ejaculate; semen pH; individual sperm motility (IM); the suitability for AI of the ejaculate (Sui), which involves the subjective combination of several quality traits; the average ejaculate volume (Vol); sperm concentration (Conc); and the average sperm production per ejaculate (Prod = Vol × Conc). The genetic relationship between all of these traits with ADG is also provided. Male libido and seminal data came either from routine evaluations of the ejaculates in an AI center or from 2 experiments in which bucks from the same population were used. Two consecutive ejaculates per male and per week were collected, leaving 7 d within weekly collections. A linear tri-trait model was used to analyze Conc, Vol, and ADG, whereas linear and threshold-linear 2-trait models were used to analyze male libido and the remaining seminal traits with ADG. A Bayesian approach was adopted for inference. Approximately 38% of ejaculates were rejected for AI primarily due to low IM scores. Variables related to the quality of the ejaculate (Ur, Ca, pH, IM, Sui) and Lib were found to be lowly heritable (h(2) ranged from 0.04 to 0.11), but repeatable. This indicates performance of bucks for seminal quality traits and libido in AI centers would be more strongly affected by management practices rather than genetic selection. Semen production traits exhibited moderate values of h(2) (0.22, 0.27, and 0.23 for Conc, Vol, and Prod, respectively), suggesting the possibility of effective selection for these traits. A moderate to high negative genetic correlation (r(g); posterior mean; highest posterior density at 95%, HPD(95%)) was estimated between Conc and Vol (-0.53, HPD(95%) = -0.76, -0.27). The ADG was estimated to have an h(2) of 0.16, to have a low, positive r(g) with Conc (0.21, HPD(95%) = -0.03, 0.48), to have a low, negative r(g) with Vol (-0.19, HPD(95%) = -0.47, 0.08), and to be genetically uncorrelated with all remaining traits analyzed. Therefore, selection for increasing ADG in paternal lines is expected to have no detrimental effects on Ur, Ca, pH, IM, Sui, and Lib and little to no effect on Conc, Vol, and Prod.
本研究旨在估计脂肪育肥期选择 ADG 的公兔系的精液和生产性状的遗传参数。所考虑的性状包括雄性性欲（Lib），定义为成功安装人工阴道；精液中是否存在尿液（Ur）和碳酸钙沉积物（Ca）；精液 pH 值；个体精子活力（IM）；精液人工授精适宜性（Sui），涉及几个质量性状的主观组合；平均精液量（Vol）；精子浓度（Conc）；以及每次射精的平均精子产量（Prod = Vol × Conc）。还提供了这些性状与 ADG 的遗传关系。雄性性欲和精液数据要么来自 AI 中心对精液的常规评估，要么来自同一群体的公兔进行的 2 项实验。每周收集 2 次，每周内留 7d。使用线性三性状模型分析 Conc、Vol 和 ADG，而使用线性和门限线性二性状模型分析雄性性欲和剩余的精液性状与 ADG。采用贝叶斯方法进行推断。大约 38%的精液因 IM 评分低而被拒绝用于 AI。与精液质量（Ur、Ca、pH、IM、Sui）和 Lib 相关的变量遗传力较低（h（2）范围为 0.04 至 0.11），但可重复。这表明在 AI 中心，公兔的精液质量性状和性欲表现将更多地受到管理实践的影响，而不是遗传选择。精液生产性状的 h（2）值适中（Conc、Vol 和 Prod 分别为 0.22、0.27 和 0.23），表明这些性状具有有效的选择可能性。Conc 和 Vol 之间估计存在中度至高度负遗传相关（r（g）；后验均值；95%最高后验密度，HPD（95%）为-0.53，HPD（95%）=-0.76，-0.27）。ADG 的 h（2）估计为 0.16，与 Conc 的 r（g）为低正相关（0.21，HPD（95%）=-0.03，0.48），与 Vol 的 r（g）为低负相关（-0.19，HPD（95%）=-0.47，0.08），与分析的所有其余性状均无遗传相关性。因此，预计在父系中选择增加 ADG 不会对 Ur、Ca、pH、IM、Sui 和 Lib 产生不利影响，对 Conc、Vol 和 Prod 的影响也很小或没有。
