Inferring relationships between Phosphorus utilization, feed per gain, and bodyweight gain in an F2 cross of Japanese quail using recursive models
Inferring relationships between Phosphorus utilization, feed per gain, and bodyweight gain in an F2 cross of Japanese quail using recursive models
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DOI：
10.3382/ps/pev376
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发表时间：
2016-04-01
期刊：
影响因子：
4.4
通讯作者：
Bennewitz, J.
中科院分区：
文献类型：
--
作者：
Beck, P.;Piepho, H-P.;Bennewitz, J.
磷的利用（PU）在家禽营养方面受到了相当多的关注。然而，迄今为止，PU 和相关性状遗传参数的可靠估计尚未见报道；然而，需要这些来评估改进的 PU 的选择是否会导致选择响应。产生了大型日本鹌鹑 F-2 杂交，并对 888 个 F2 个体进行了 PU、体重增加 (BWG) 和单位增重饲料 (F:G) 的表型分析。因为可以合理地假设这些性状之间的相互关系是复杂的，所以使用了结构方程模型。结构系数 lambda(ij) 描述了特征 j 对特征 i 具有递归效应的模型中特征 i 相对于特征 j 的变化率。根据生物学知识先验选择三个递归结构系数（lambda（F：G，PU），lambda（BWG，PU），lambda（BWG，F：G））。该模型使用 ASReml 软件进行拟合。使用δ方法近似估计方差分量和遗传参数的标准误差。 PU、F:G和BWG的遗传力分别为0.136、0.118和0.092。结构系数 (lambda) over cap (F:G,PU) = -0.177 表明 PU 的增加导致 F: G 降低并因此得到改善。估计值 (lambda) over cap (BWG,F:G) = -0.963 表明改进的 F: G 导致 BWG 增加。 PU 对 BWG 的总体影响为 (lambda) 上限 (BWG,PU) + (lambda) 上限 (F:G,PU) x (lambda) 上限 (BWG,F:G) = 0.374，即在为期 5 天的数据收集期间，PU 增加 1% 导致 BWG 增加 0.374 g。 PU和F:G之间以及BWG和F:G之间的表型和遗传相关性为负相关，PU和BWG之间为正相关。这些相关性是由直接遗传效应（多效性基因或连锁不平衡的基因）以及间接遗传效应（影响性状 j 的基因间接影响性状 i）驱动的。结构方程模型的应用有助于我们理解鹌鹑中 PU、F:G 和 BWG 之间复杂的生物学关系。 PU表现出的遗传力足以在针对这种很难测量的性状进行育种时实现选择反应。
Phosphorus utilization (PU) has received considerable attention in poultry nutrition. However, reliable estimates of genetic parameters for PU and related traits have largely not been reported until now; however, these are needed to assess whether selection for an improved PU would result in selection response. A large Japanese quail F-2 cross was generated and 888 F2 individuals were phenotyped for PU, body-weight gain (BWG), and feed per gain (F:G). Because it can reasonably be assumed that the interrelationships between these traits are complex, structural equation models were used. The structural coefficient lambda(ij) describes the rate of change of trait i with respect to trait j for a model with a recursive effect of trait j on trait i. Three recursive structural coefficients (lambda(F:G,PU), lambda(BWG,PU), lambda(BWG,F:G)) were selected a priori based on biological knowledge. The model was fitted using ASReml software. Standard errors of estimated variance components and genetic parameters were approximated using the delta method. The heritability of PU, F: G, and BWG were 0.136, 0.118, and 0.092. The structural co-efficient (lambda) over cap (F:G,PU) = -0.177 indicates that an increase in PU leads to reduced and thus improved F: G. The estimate (lambda) over cap (BWG,F:G) = -0.963 indicates that improved F: G leads to an increase in BWG. The overall effect of PU on BWG was (lambda) over cap (BWG,PU) + (lambda) over cap (F:G,PU) x (lambda) over cap (BWG,F:G) = 0.374, i.e. an increase in PU of 1% leads to an increase of BWG of 0.374 g in the data collection period, which spanned five days. The phenotypic and genetic correlations were negative between PU and F: G as well as between BWG and F: G and were positive between PU and BWG. These correlations are driven by direct genetic effects (pleiotropic genes or genes being in linkage disequilibrium) as well as by indirect genetic effects (genes affecting trait j affected indirectly trait i). The application of structural equation models contributed to our understanding of the complex biological relationship between PU, F: G, and BWG in quails. PU shows a heritability that is sufficient to achieve a selection response when breeding for this very-hard-to-measure trait.