Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada.
J Anim Sci. 2010 Jun;88(6):1957-66. doi: 10.2527/jas.2009-2004. Epub 2010 Feb 26.
Genotype x environment (GxE) interactions can reduce the accuracy of a model to predict the performance of an animal and have an undesirable influence if not accounted for when estimating breeding values. Consequently, identification of these GxE is necessary when considering a turkey breeding program. Reranking based on the genetic prediction of turkey egg production, fertility, and hatchability in different seasons was indicative of a potential GxE interaction. Quantification of the GxE interactions was based on the genetic correlation estimated when traits were expressed in different seasons. Egg production was expressed as the percentage of days with an egg produced; fertility represented the proportion of hatched eggs that contained a fertile embryo; and hatchability was defined as the percentage of fertile eggs that produced a live bird. Variance components and heritability for egg production, fertility, and hatchability were estimated using ASReml. The heritability (h(2)) of egg production was calculated to be 0.32 for both lines with the phenotypic and genetic variance, 141.3 and 45.58 (percent days with egg produced)(2) and 118.3 and 38.35 (percent days with egg produced)(2) for female and male lines, respectively. The h(2) estimates for fertility were 0.08 in both lines with and of 293.3%(2) and 24.03%(2), and 576.9%(2) and 48.43%(2) for female and male lines, respectively. The hatchability h(2), and estimates were 0.09, 267.1%(2), and 24.44%(2), respectively, for the female line and 0.15, 582.2%(2), and 90.01%(2) for the male line, respectively. Based on an animal model, the variance components were used to calculate estimated breeding values for each trait. The annual fluctuation in estimated breeding values resulted in the need to evaluate egg number, fertility, and hatchability as 2 traits, summer and winter lay. The correlation between the 2 traits was less than unity (female line: r(egg production) = 0.76, r(fertility) = -0.20, r(hatchability) = 0.75 and male line: r(egg production) = 0.86, r(fertility) = 0.19, r(hatchability) = 0.68) suggesting a GxE interaction, and animals will significantly rerank in genetic predictions for these reproductive phenotypes in different seasons of lay. Egg production, fertility, and hatchability in turkeys could be considered as 2 distinct traits in an animal model based on season of lay.
基因型与环境（GxE）互作可降低模型预测动物性能的准确性，如果在估计育种值时未加以考虑，则会产生不良影响。因此，在考虑火鸡育种计划时，有必要识别这些 GxE。基于不同季节火鸡产蛋、受精和孵化性能的遗传预测进行重新排序，表明存在潜在的 GxE 互作。GxE 互作的量化是基于不同季节表达性状时估计的遗传相关系数进行的。产蛋率表示产蛋天数的百分比；受精率表示孵化出的含有可育胚胎的蛋的比例；孵化率定义为可育蛋产生活禽的百分比。使用 ASReml 估计产蛋、受精和孵化率的方差分量和遗传力。两个系的产蛋遗传力（h(2)）分别为 0.32，表型和遗传方差分别为 141.3 和 45.58（产蛋天数百分比）(2)和 118.3 和 38.35（产蛋天数百分比）(2)，雌性和雄性系。两个系的受精遗传力（h(2)）分别为 0.08，且为 293.3%(2)和 24.03%(2)，576.9%(2)和 48.43%(2)，雌性和雄性系。雌性系的孵化遗传力（h(2)）和估计值分别为 0.09、267.1%(2)和 24.44%(2)，而雄性系分别为 0.15、582.2%(2)和 90.01%(2)。基于动物模型，使用方差分量计算每个性状的估计育种值。估计育种值的年波动导致需要将蛋数、受精和孵化率评估为 2 个性状，夏季和冬季产蛋。这两个性状之间的相关性小于 1（雌性系：r(产蛋量) = 0.76，r(受精率) = -0.20，r(孵化率) = 0.75，雄性系：r(产蛋量) = 0.86，r(受精率) = 0.19，r(孵化率) = 0.68），表明存在 GxE 互作，动物在不同产蛋季节的这些繁殖表型的遗传预测中会显著重新排序。火鸡的产蛋率、受精率和孵化率可根据产蛋季节在动物模型中视为 2 个不同的性状。
