As cage-free production systems become increasingly popular, behavioral traits such as nesting behavior and temperament have become more important. The objective of this study was to estimate heritabilities for frequency of perching and proportion of floor eggs and their genetic correlation in two Rhode Island Red lines. The percent of hens observed perching tended to increase and the proportion of eggs laid on the floor tended to decrease as the test progressed. This suggests the ability of hens to learn to use nests and perches. Under the bivariate repeatability model, estimates of heritability in the two lines were 0.22 ± 0.04 and 0.07 ± 0.05 for the percent of hens perching, and 0.52 ± 0.05 and 0.45 ± 0.05 for the percent of floor eggs. Estimates of the genetic correlation between perching and floor eggs were − 0.26 ± 0.14 and − 0.19 ± 0.27 for the two lines, suggesting that, genetically, there was some tendency for hens that better use perches to also use nests; but the phenotypic correlation was close to zero. Random regression models indicated the presence of a genetic component for learning ability. In conclusion, perching and tendency to lay floor eggs were shown to be a learned behavior, which stresses the importance of proper management and training of pullets and young hens. A significant genetic component was found, confirming the possibility to improve nesting behavior for cage-free systems through genetic selection.

中文翻译：

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罗德岛红鸡栖息行为的遗传力及其与地蛋发生率的遗传关系

随着无笼生产系统越来越流行，筑巢行为和气质等行为特征变得更加重要。本研究的目的是估计两条罗德岛红系中栖息频率和地面鸡蛋比例的遗传力及其遗传相关性。随着测试的进行，观察到的母鸡的百分比趋于增加，而在地板上产蛋的比例趋于减少。这表明母鸡学习使用巢穴和栖木的能力。在双变量可重复性模型下，两个品系中母鸡栖息百分比的遗传力估计值分别为 0.22 ± 0.04 和 0.07 ± 0.05，地板鸡蛋百分比的估计值分别为 0.52 ± 0.05 和 0.45 ± 0.05。栖息和地板鸡蛋之间的遗传相关性估计为 - 0.26 ± 0.14 和 - 0.19 ± 0。27 对于这两个品系，这表明从基因上讲，更好地使用栖息地的母鸡也有使用巢穴​​的趋势；但表型相关性接近于零。随机回归模型表明存在学习能力的遗传成分。总之，栖息和下地板蛋的倾向被证明是一种学习行为，这强调了对小母鸡和年轻母鸡进行适当管理和培训的重要性。发现了一个重要的遗传成分，证实了通过遗传选择改善无笼系统筑巢行为的可能性。随机回归模型表明存在学习能力的遗传成分。总之，栖息和下地板蛋的倾向被证明是一种学习行为，这强调了对小母鸡和年轻母鸡进行适当管理和培训的重要性。发现了一个重要的遗传成分，证实了通过遗传选择改善无笼系统筑巢行为的可能性。随机回归模型表明存在学习能力的遗传成分。总之，栖息和下地板蛋的倾向被证明是一种学习行为，这强调了对小母鸡和年轻母鸡进行适当管理和培训的重要性。发现了一个重要的遗传成分，证实了通过遗传选择改善无笼系统筑巢行为的可能性。