Genetic correlations between the cumulative pseudo-survival rate, milk yield, and somatic cell score during lactation in Holstein cattle in Japan using a random regression model
Genetic correlations between the cumulative pseudo-survival rate, milk yield, and somatic cell score during lactation in Holstein cattle in Japan using a random regression model
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DOI：
10.3168/jds.2016-12311
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发表时间：
2017-09-01
影响因子：
3.5
通讯作者：
Takeda, H.
中科院分区：
文献类型：
--
作者：
Sasaki, O.;Aihara, M.;Takeda, H.
奶牛哺乳期间长寿、产奶量和体细胞评分(SCS)之间的遗传相关性的趋势很难追踪。本研究分析了泌乳期间产奶量、SCS和累计假存活率(PSR)之间的遗传相关性的变化，并探讨了产奶量和SCS信息对PSR估计育种值(EBV)可靠性的影响。获得了2004年至2013年日本荷斯坦奶牛的试验日产奶量、SCS和PSR记录。数据的随机子集被用于分析(825个牛群，205,383头奶牛)。该数据集被随机分为5个子集(162168个牛群，83,389-95,854头奶牛)，并在每个子集中独立地估计遗传参数。用多性状随机回归动物模型对数据进行分析，包括整个哺乳期的残效(H0)、5个哺乳期的残效(H5)或这两种残效(HD)。产奶量遗传力增加到310~351日龄(DIM)，SCS遗传力增加到330~344天。PSR的遗传力估计随着DIM从0.00增加到0.05而增加。产奶量与SCS之间的遗传相关在455Dim时增加到-0.60以下。产奶量与产奶量之间的遗传相关增加到342~355 DIM(0.53~0.57)。在180dim附近，SCS与PSR之间的遗传相关为-0.82~-0.83，在455dim时，SCS与PSR之间的遗传相关为-0.65~-0.71。在不考虑相关性状影响的情况下，具有30个或30个以上记录子代的父本PSR的EBV信度为0.17~0.45。观察到EBV在257(HO)或322(HD)Dim时的可靠性最高。当考虑PSR与产奶量和SCS的相关性时，PSR估计的可靠性提高到0.31-0.76。H5的遗传参数估计与HD相同。HO与H5、HD PSR的EBV等级相关系数均大于0.9。此外，HO的PSR的EBV信度与H5和HD相似。因此，HO的遗传参数估计与H5和HD的遗传参数估计没有实质性差异。当使用与PSR遗传相关的产奶量和SCS时，PSR的可靠性增加。估计PSR和产奶量之间以及PSR和SCS之间的遗传相关性对于延长奶牛群寿命的管理和育种决策是有用的。
Trends in genetic correlations between longevity, milk yield, and somatic cell score (SCS) during lactation in cows are difficult to trace. In this study, changes in the genetic correlations between milk yield, SCS, and cumulative pseudo-survival rate (PSR) during lactation were examined, and the effect of milk yield and SCS information on the reliability of estimated breeding value (EBV) of PSR were determined. Test day milk yield, SCS, and PSR records were obtained for Holstein cows in Japan from 2004 to 2013. A random subset of the data was used for the analysis (825 herds, 205,383 cows). This data set was randomly divided into 5 subsets (162168 herds, 83,389-95,854 cows), and genetic parameters were estimated in each subset independently. Data were analyzed using multiple-trait random regression animal models including either the residual effect for the whole lactation period (H0), the residual effects for 5 lactation stages (H5), or both of these residual effects (HD). Milk yield heritability increased until 310 to 351 d in milk (DIM) and SCS heritability increased until 330 to 344 DIM. Heritability estimates for PSR increased with DIM from 0.00 to 0.05. The genetic correlation between milk yield and SCS increased negatively to under -0.60 at 455 DIM. The genetic correlation between milk yield and PSR increased until 342 to 355 DIM (0.53-0.57). The genetic correlation between the SCS and PSR was -0.82 to -0.83 at around 180 DIM, and decreased to -0.65 to -0.71 at 455 DIM. The reliability of EBV of PSR for sires with 30 or more recorded daughters was 0.17 to 0.45 when the effects of correlated traits were ignored. The maximum reliability of EBV was observed at 257 (HO) or 322 (HD) DIM. When the correlations of PSR with milk yield and SCS were considered, the reliabilities of PSR estimates increased to 0.31-0.76. The genetic parameter estimates of H5 were the same as those for HD. The rank correlation coefficients of the EBV of PSR between HO and H5 or HD were greater than 0.9. Additionally, the reliabilities of EBV of PSR of HO were similar to those for H5 and HD. Therefore, the genetic parameter estimates in HO were not substantially different from those in H5 and HD. When milk yield and SCS, which were genetically correlated with PSR, were used, the reliability of PSR increased. Estimates of the genetic correlations between PSR and milk yield and between PSR and SCS are useful for management and breeding decisions to extend the herd life of cows.