中国农业科学 ›› 2017, Vol. 50 ›› Issue (10): 1885-1892.doi: 10.3864/j.issn.0578-1752.2017.10.013

• 畜牧·兽医·资源昆虫 • 上一篇    下一篇

用随机回归模型估计宁夏地区荷斯坦牛头胎测定日产奶量遗传参数

任小丽1,2,刘澳星1,李想1,张旭1,王雅春1,邵怀峰3,秦春华4,王瑜3,温万3,张胜利1

 
  

  1. 1中国农业大学动物科技学院,北京 100193;2河南省奶牛生产性能测定中心 郑州 450046;3宁夏回族自治区畜牧工作站,银川750001;4宁夏四正生物技术工程研究中心,银川 750200
  • 收稿日期:2015-11-24 出版日期:2017-05-16 发布日期:2017-05-16
  • 通讯作者: 王雅春,E-mail:wangyachun@cau.edu.cn
  • 作者简介:任小丽,E-mail:renxl1990@163.com。刘澳星,E-mail:liuaoxing@cau.edu.cn。任小丽和刘澳星位同等贡献作者。
  • 基金资助:
    宁夏自治区农业育种专项-《优质高产奶牛育种》项目、现代农业(奶牛)产业技术体系建设专项资金(CARS-37)

Genetic Parameters Estimation of Test Day Milk Yield in Holstein Heifers in Ningxia Using a Random Regression Test-Day Model

REN XiaoLi1,2, LIU AoXing1, LI Xiang1, ZHANG Xu1, WANG YaChun1, SHAO HuaiFeng3, QIN ChunHua4, WANG Yu3, WEN Wan3, ZHANG ShengLi1   

  1. 1College of Animal Science and Technology, China Agricultural University, Beijing 100193; 2Henan Dairy Improvement Center Zhengzhou 450046; 3Ningxia Animal Husbandry Station, Yinchuan 750001;4 Ningxia Synogen Biotech Engineering Research Center, Yinchuan 750001
  • Received:2015-11-24 Online:2017-05-16 Published:2017-05-16

摘要: 【目的】通过拟合泌乳曲线对影响宁夏地区荷斯坦牛测定日产奶量的诸多因素进行分析,并采用随机回归测定日模型估计遗传参数,为后续估计乳成分和体细胞数遗传参数及个体育种值估计奠定基础,同时也为制定适合该群体的优化育种方案提供参数。【方法】收集了2009—2013年间,宁夏地区24个牛场38 592头荷斯坦牛原始DHI数据,共包含550 078条测定日产奶量记录。质控标准为:产犊月龄为22—36 mo、泌乳天数为5—305 d及日产奶量为5.9—53.3 kg。质控后,共得到14 320头母牛的127 478条测定日记录(占原始记录的23.14%)。将有表型的母牛至少向上追溯三代(父母、祖父母、外祖父母),得到遗传评估所用的系谱文件,共包含24 272头奶牛。使用Excel 2013计算各测定日的平均产奶量,利用SAS 9.1软件的非线性回归过程(NLIN)结合Wood模型拟合群体水平的泌乳曲线。采用随机回归测定日动物模型,通过DMU 5.2 软件对头胎产奶量进行遗传参数估计。随机回归测定日模型中包括了一般固定效应、固定回归项及随机回归项三类效应。研究中使用场-测定日作为固定效应、产犊年季效应作为固定回归项,并将加性遗传效应和永久环境效应作为随机回归项。测定日子模型采用4阶勒项德多项式(Legendre polynomials)。根据宁夏地区气候特点,将产犊季节划分为春(3月11日至5月20日)、夏(5月21日至8月25日)、秋(8月26日至10月15日)和冬(10月16日至3月10日)四季。【结果】宁夏地区荷斯坦牛头胎测定日产奶量群体均值为29.66 kg,在泌乳90 d时达到泌乳高峰,高峰产奶量为31.84 kg。通过不同产犊年份、产犊季节和牧场效应组合下的泌乳曲线拟合效果分析,以上因素通过影响泌乳曲线拟合效果进而影响头胎产奶量。在使用测定日模型估计头胎遗传参数时均应通过子模型拟合考虑其泌乳曲线的差异,在产奶量遗传评估模型中予以考虑。产奶量性状5—305d的遗传力在0.08—0.29之间,305d产奶量的总遗传力为0.16。【结论】通过使用wood模型拟合宁夏地区荷斯坦牛头胎泌乳曲线,优化了适合于该群体的测定日模型。利用修改后的测定日模型,估计了宁夏地区荷斯坦牛测定日产奶量的遗传参数。305 d遗传力(0.16)略低于其他群体的同类文研究结果。在测定日模型评估生产性能记录时,应注意对残差方差的处理并关注构建分子亲缘关系矩阵所需系谱的完整性,以保证遗传评估的可靠性。本研究为日后使用多性状随机回归测定日模型估计泌乳性状遗传参数研究奠定了基础。

关键词: 测定日产奶量, 遗传参数, 随机回归模型, 宁夏, 荷斯坦牛

Abstract: 【Objective】This experiment was conducted to quantify the effect of environmental factors on milk yield of first lactation Holsteins in Ningxia, and to estimate genetic parameters of test day milk yield using test-day model, to provide a theoretical foundation for genetic parameter and breeding value estimation of milk components and somatic cells, and provide basic parameters for optimal breeding scheme which is suited to the Holstein population in Ningxia.【Method】A total of 550 078 test-day milk yield records from Holstein in Ningxia were collected, and the standards of calving month between 22-36 mo, the milk days between 5-305 d, and test day milk yield between 5.9-53.3kg were used to edit data, and finally a total of 127478 test-day milk yield records from 14320 Holstein heifers distributed in 24 herds between 2009 and 2013 in Ningxia were used in lactation curve mimicking and genetic analysis. Pedigree information of three generations were collected (father, mother, grandfather and grandmother from both father side and mother side) to form the pedigree file consisting 24 272 individuals. Microsoft Excel 2013 was used to manage the data to derive average milk production for each test-day, and NLIN procedure of SAS 9.1 was used to fit the Wood model and used to mimic the lactation curve to derive the population characters of milk yield. A random regression test-day animal model was employed and DMU 5.2 software was used for parameter estimation. The model included general fixed effect and fixed regression, random regression. In the present study, herd-test-day was the fixed effects, and a fixed regression were fitted for calving year and calving month combination effects, direct additive genetic, permanent environment were the random effects. Regression curves were modeled using Legendre polynomials of order 4. Based on climate characteristics in Ningxia, four calving seasons were categorized, spring (Mar. 11th to May 20th), summer (May 21st to Aug. 25th), autumn (Aug. 26th to Oct. 15th) and winter (Oct.16th to Mar. 10th).【Result】 The results showed that the average of test-day milk yield in Ningxia was 29.66 kg, milk yield reached its peak at about 90 days and peak yield was 31.84 kg. Through fitting lactation curves to first lactation cows in different seasons, calving years, and farms, the effect of these factors on lactation curves were quantified. Furthermore, lactation curves should be fitted as sub-models in the model for genetic evaluation. The heritabilities of 5-305 day milk yield were from 0.08 to 0.29, and the overall heritability of daily milk yield was 0.16. 【Conclusion】The study mimicked lactation curves for first lactation Holstein cows in Ningxia using WOOD model, the proper model was defined for this population. Results of estimated heritability for daily milk yield was lower than the results in the literatures using similar models. To evaluate the performance of test-day model, the hypothesis for residual variance (e) and integrity of pedigree needs to pay attention. These estimates derived from current study will provide reference for evaluating milk components and somatic cell counts using random regression model, and further establishing breeding value estimation system for performance of Holstein in Ningxia.

Key words: test-day milk yield, genetic parameters, random regression model, Ningxia, Holstein