Buzanskas M E, Savegnago R P, Grossi D A, Venturini G C, Queiroz S A, Silva L O C, Júnior R A A Torres, Munari D P, Alencar M M
Departamento de Ciências Exatas, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Jaboticabal, São Paulo14884-900, Brazil.
Reprod Fertil Dev. 2013;25(5):775-81. doi: 10.1071/RD12132.
Phenotypic data from female Canchim beef cattle were used to obtain estimates of genetic parameters for reproduction and growth traits using a linear animal mixed model. In addition, relationships among animal estimated breeding values (EBVs) for these traits were explored using principal component analysis. The traits studied in female Canchim cattle were age at first calving (AFC), age at second calving (ASC), calving interval (CI), and bodyweight at 420 days of age (BW420). The heritability estimates for AFC, ASC, CI and BW420 were 0.03±0.01, 0.07±0.01, 0.06±0.02, and 0.24±0.02, respectively. The genetic correlations for AFC with ASC, AFC with CI, AFC with BW420, ASC with CI, ASC with BW420, and CI with BW420 were 0.87±0.07, 0.23±0.02, -0.15±0.01, 0.67±0.13, -0.07±0.13, and 0.02±0.14, respectively. Standardised EBVs for AFC, ASC and CI exhibited a high association with the first principal component, whereas the standardised EBV for BW420 was closely associated with the second principal component. The heritability estimates for AFC, ASC and CI suggest that these traits would respond slowly to selection. However, selection response could be enhanced by constructing selection indices based on the principal components.
利用线性动物混合模型，对雌性坎辛肉牛的表型数据进行分析，以获得繁殖和生长性状的遗传参数估计值。此外，还运用主成分分析方法探究了这些性状的动物估计育种值（EBV）之间的关系。在雌性坎辛牛中研究的性状包括初产年龄（AFC）、二胎产犊年龄（ASC）、产犊间隔（CI）以及420日龄体重（BW420）。AFC、ASC、CI和BW420的遗传力估计值分别为0.03±0.01、0.07±0.01、0.06±0.02和0.24±0.02。AFC与ASC、AFC与CI、AFC与BW420、ASC与CI、ASC与BW420以及CI与BW420的遗传相关系数分别为0.87±0.07、0.23±0.02、-0.15±0.01、0.67±0.13、-0.07±0.13和0.02±0.14。AFC、ASC和CI的标准化EBV与第一主成分高度相关，而BW420的标准化EBV与第二主成分密切相关。AFC、ASC和CI的遗传力估计值表明，这些性状对选择的反应较为缓慢。然而，通过基于主成分构建选择指数，可以提高选择反应。
