Comparison of the multi-trait animal model and the traditional repeatability model was carried out using data obtained from 6,424 Landrace and 20,835 Yorkshire sows farrowed from January 2000 to April 2018 in order to estimate genetic parameters for litter traits at different parities. Specifically, records of the total number born (TNB), number born alive (NBA), total number of mortality (MORT), number of stillborn (NSB) and number of mummified pigs (MUM) were used. Although results showed the heterogeneity of heritability for litter traits at different parities, the mean heritability estimates from the multi-trait model were found to be higher than those of the repeatability model for all traits in both pig breeds. In terms of genetic correlation between parities, a slight difference in genetic control in the first parity was noted for TNB and NBA in Landrace and Yorkshire pigs. The correlation between the first parity and later parities ranged from 0.48 to 0.74 for TNB and NBA in both breeds. Moreover, genetic correlation between parities for MORT and NSB was observed to be high for parities higher than 2 in Yorkshire pigs. For MUM, genetic correlation between the first and other parities was generally low in both breeds, indicating that culling pigs on the basis of MUM at the first parity could probably be unreasonable. Overall, the results of this study suggest that the multi-trait approach for litter size traits is useful for the accurate estimation of genetic parameters.

中文翻译：

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纯种长白猪和约克夏猪不同产仔性状的遗传参数。

使用2000年1月至2018年4月分娩的6,424头地方品种和20,835头约克郡母猪获得的数据对多性状动物模型和传统可重复性模型进行了比较，以估计不同胎次性状的遗传参数。具体而言，使用了总出生数（TNB），活产数（NBA），总死亡数（MORT），死产数（NSB）和木乃伊猪数量（MUM）的记录。尽管结果显示了不同胎龄仔猪性状的遗传力异质性，但从多性状模型得出的平均遗传力估计值要高于两个猪品种中所有性状的重复性模型。就胎次之间的遗传相关而言，在田纳西猪和约克郡猪中，TNB和NBA在第一胎的遗传控制上略有不同。两个品种的TNB和NBA的第一胎和后胎之间的相关性在0.48到0.74之间。此外，对于约克郡猪中大于2的胎次，观察到MORT和NSB胎次之间的遗传相关性很高。对于MUM，两个品种的第一胎和其他胎之间的遗传相关性通常较低，这表明在第一胎时以MUM为基础淘汰猪可能是不合理的。总体而言，这项研究的结果表明，对垫料大小性状的多性状方法对于准确估算遗传参数很有用。两个品种的TNB和NBA 74。此外，对于约克郡猪中大于2的胎次，观察到MORT和NSB胎次之间的遗传相关性很高。对于MUM，两个品种的第一胎和其他胎之间的遗传相关性通常较低，这表明在第一胎时以MUM为基础淘汰猪可能是不合理的。总体而言，这项研究的结果表明，对垫料大小性状的多性状方法对于准确估算遗传参数很有用。两个品种的TNB和NBA 74。此外，对于约克郡猪中大于2的胎次，观察到MORT和NSB胎次之间的遗传相关性很高。对于MUM，两个品种的第一胎和其他胎之间的遗传相关性通常较低，这表明在第一胎时以MUM为基础淘汰猪可能是不合理的。总体而言，这项研究的结果表明，对垫料大小性状的多性状分析方法对于准确估算遗传参数很有用。表明在第一次胎次基础上以MUM为基础淘汰猪可能是不合理的。总体而言，这项研究的结果表明，对垫料大小性状的多性状分析方法对于准确估算遗传参数很有用。表明在第一次胎次基础上以MUM为基础淘汰猪可能是不合理的。总体而言，这项研究的结果表明，对垫料大小性状的多性状分析方法对于准确估算遗传参数很有用。