• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Tropical Animal Health and Production >Genetic evaluation of growth in Barki sheep using random regression models
【24h】

Genetic evaluation of growth in Barki sheep using random regression models

机译：随机回归模型的Barki绵羊生长的遗传评价

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The objective of the current study was to estimate covariance components of growth at different ages from birth to yearling in Barki lambs. A total of 16,496 records for body weights at birth (W0), 3 (W3), 6 (W6), 9 (W9), and 12 (12) months of age for Barki lambs were available. Two statistical approaches were used; multi-trait (MT) and random regression (RR) animal models assuming two random effects only, additive genetic effect (sigma(2)(a)) and permanent environmental effect (sigma(2)(pe)) of the animal. Regarding the RR model, Legendre polynomials (LP) of different orders for the random parts were compared in order to evaluate the most appropriate model. Bayesian information and Akaike information criteria suggested that the optimal RR model included the third order for fixed effect of lamb age and sigma(2)(pe), and fourth order of LP for sigma(2)(a) (LP343). Estimates of direct heritability (h(a)(2)) from LP343 showed an ascending pattern, as it was 0.06 +/- 0.03 for birth weight and reached to the peak at 9 months (0.42 +/- 0.02). Thereafter, it declined again at the end of trajectory (12 months of age; 0.27 +/- 0.03). The MT model showed a fluctuated pattern and lower estimates of h(a)(2) (0.19 +/- 0.03, 0.11 +/- 0.02, 0.12 +/- 0.02, 0.11 +/- 0.03, and 0.16 +/- 0.04 for W0, W3, W6, W9, and W12, respectively). Considerably, similar ascending patterns of the ratio of sigma(2)(pe) to phenotypic variance were reported from both RR (from 3 to 50%) and MT models (from 5 to 20%). Of interest, the RR model showed higher predicting ability of the breeding values compared with the MT model, which is an indicator for the suitability of RR models for analyzing the consecutive growth traits in sheep. Results suggested that the Barki sheep has a potential for genetic selection based on weight at different ages with selection likely to be more efficient at 9 months of age.
机译：目前研究的目的是从出生于Barki Lambs的七岁时估计不同年龄的不同年龄增长的协方差。在出生（W0），3（W3），6（W6），9（W9），9（W9）和12（12）个月的Barki Lambs中，共有16,496条记录。使用了两种统计方法;多特征（MT）和随机回归（RR）动物模型仅仅是两种随机效应，添加剂遗传效应（Sigma（2）（a））和动物的永久环境效果（Sigma（2）（PE））。关于RR模型，比较了随机部件的不同订单的Legendre多项式（LP），以评估最合适的模型。贝叶斯信息和Akaike信息标准表明，最佳RR模型包括羊羔年龄和Sigma（2）（PE）和Sigma（2）（A）（1）（LP343）的第四阶的第三顺序。 LP343的直接遗传性（H（A）（2））的估计显示出升高的模式，出生体重为0.06 +/- 0.03，并在9个月内达到峰（0.42 +/- 0.02）。此后，它在轨迹结束时再次下降（12个月的年龄; 0.27 +/- 0.03）。 MT模型显示出波动的图案和较低的H（a）（2）（0.19 +/- 0.03,0.11 +/- 0.02,0.12 +/- 0.02,0.11 +/- 0.03和0.16 +/- 0.04 W0，W3，W6，W9和W12分别）。相当地，从RR（从3至50％）和MT模型（5至20％）中报告了Sigma（2）（PE）与表型方差的相似升序模式。感兴趣的是，与MT模型相比，RR模型显示出育种值的更高预测能力，这是用于分析绵羊连续生长性状的RR模型的适用性的指标。结果表明，巴克绵羊在不同年龄的重量的遗传选择具有遗传选择，在9个月的年龄的选择可能更有效。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号