Department of Animal Science, Iowa State University, 806 Stange Road, 239E Kildee Hall, Ames, IA, 50010, USA.
Hy-Line International, 2583 240th Street, Dallas Center, IA, 50063, USA.
Genet Sel Evol. 2021 Apr 21;53(1):38. doi: 10.1186/s12711-021-00630-5.
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.
随着无笼养殖系统越来越受欢迎，筑巢行为和性情等行为特征变得更加重要。本研究的目的是估计两个罗得岛红品系中栖息频率和地板蛋比例的遗传力及其遗传相关性。
随着测试的进行，观察到的母鸡栖息比例趋于增加，而在地板上产卵的比例趋于减少。这表明母鸡有能力学习使用巢和栖息处。在二元重复模型下，两条品系中母鸡栖息比例的遗传力估计值分别为 0.22±0.04 和 0.07±0.05，地板蛋比例的遗传力估计值分别为 0.52±0.05 和 0.45±0.05。栖息与地板蛋之间的遗传相关性估计值分别为-0.26±0.14 和-0.19±0.27，表明在遗传上，更好地利用栖息处的母鸡也有使用巢的倾向；但表型相关性接近零。随机回归模型表明存在学习能力的遗传成分。
总之，栖息和倾向于在地板上产卵被证明是一种习得行为，这强调了对育雏和年轻母鸡进行适当管理和训练的重要性。发现了一个显著的遗传成分，证实了通过遗传选择改善无笼系统筑巢行为的可能性。
