National Engineering Research Center For Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.
Guangdong Wens Foodstuffs Group, Xinxing, China.
J Anim Sci. 2018 Apr 14;96(4):1215-1220. doi: 10.1093/jas/sky066.
Univariate or bivariate animal models were used to estimate the variance components and co-variance components for eight reproductive traits: total number born (TNB), number born alive (NBA), total litter weight of piglets born alive (BALWT), number of healthy births (NHB), number of weak births (NWB), number of deformed fetuses (NDF), number of stillborn (NSB), and number of mummified pigs (MUMM). In addition, the phenotypic and genetic correlations between traits at different parities were also estimated. The results showed that the heritabilities of the eight reproductive traits were lower than 0.10. Genetic correlations between NHB and TNB, NBA, or BALWT were 0.68, 0.84 and 0.89 respectively; whereas genetic correlations between NHB and NWB, NDF, NSB or MUMM were negative or close to 0, ranging from -0.28 to 0.13. NHB was relatively identified as an ideal informative trait for selection for improved reproduction. Furthermore, genetic correlations between different parities for all traits, except for NDF were strongly positive, showing that it was reasonable to consider different parities as the same trait. For NDF, genetic correlations between the first and the other parities were low, indicating that it was probably unreasonable to cull pigs according to the NDF at first parity. Optimum reproductive traits were observed at the third parity, and reinforcing the management of sows in the first and > 4 parities can be a practical method for improving reproductive traits.
采用单变量或双变量动物模型估计了 8 个繁殖性状的方差分量和协方差分量：总产仔数（TNB）、产活仔数（NBA）、产活仔总初生重（BALWT）、健康产仔数（NHB）、弱仔产仔数（NWB）、畸形胎仔数（NDF）、死胎数（NSB）和木乃伊化仔猪数（MUMM）。此外，还估计了不同胎次性状之间的表型和遗传相关性。结果表明，8 个繁殖性状的遗传力均低于 0.10。NHB 与 TNB、NBA 或 BALWT 之间的遗传相关性分别为 0.68、0.84 和 0.89；而 NHB 与 NWB、NDF、NSB 或 MUMM 之间的遗传相关性为负值或接近 0，范围从-0.28 到 0.13。NHB 被认为是选择改良繁殖性能的理想信息性状。此外，除 NDF 外，所有性状不同胎次之间的遗传相关性均为强正相关，表明将不同胎次视为同一性状是合理的。对于 NDF，第一胎和其他胎次之间的遗传相关性较低，表明根据第一胎的 NDF 淘汰猪可能不合理。在第三胎次观察到最佳繁殖性状，加强对第一胎和>4 胎次母猪的管理可能是提高繁殖性状的实用方法。
