Casto-Rebollo C, Nuñez P, Gol S, Reixach J, Ibáñez-Escriche N
Institute for Animal Science, Universitat Politècnica de València, València, Spain.
Selección Batallé S.A., Riudarenes, Spain.
Animal. 2025 Feb;19(2):101415. doi: 10.1016/j.animal.2024.101415. Epub 2024 Dec 28.
There is a growing need to produce more resilient livestock that can cope with extreme environments and their associated impacts. Daily feed intake (DFI) is a promising metric for the development of resilience indicators (RIs), as reduced feed consumption is widely recognised as a clinical sign of disease. However, there is no consensus on which DFI-based RIs are the most informative. The objectives of this study were: (i) to evaluate the most common DFI-based RIs and their relationships with feed efficiency traits (FETs), (ii) to investigate the relationship between these indicators and progeny mortality rates on commercial farms, and (iii) to gain insight into their biological mechanisms. A total of 111 121 DFI records of 1 634 healthy purebred Pietrain boars were used, ranging from 47 to 90 days, with an average of 69 DFI records per boar. Three RIs were calculated: residual variance, RMSE and logarithm of the variance of the deviations from an expected pattern (LnVar). A classical animal model was used to estimate the variance components of each RI, and a bivariate model was implemented to estimate the genetic correlation between RIs and the FET. Furthermore, a preliminary mortality study was carried out using data from 6 889 progeny of 55 boars on farms catalogued as virulent for porcine reproductive and respiratory syndrome. Progeny mortality was calculated for each contemporary group (farm and batch) of the offspring, and sires were classified into three levels of resilience. A Bayesian linear model was used to determine whether the differences in progeny mortality rate between the levels of resilience were relevant. On the other hand, a weighted single-step genome-wide association study was performed for each RI and the FET, using a total of 1 216 genotypes. RIs showed moderate heritability (h = 0.27-0.49) and moderate to strong genetic correlation with FET. Progeny of resilient sires had an 80% probability of at least a 2.5% higher survival rate. Overlapping genomic regions were found for RIs and feed conversion ratio, highlighting DOCK1, SYK and SPTLC1 genes for their potential roles in modulating immune responses and/or metabolism. The LnVar of deviations from the population mean was the most promising indicators (LnVar-Pop) for disease resilience, as it was the RI that better captured differences in progeny mortality. Furthermore, these results suggest a common biological basis for RIs and FET of interest to breeding programmes. Further studies are needed to validate them.
培育出更具适应力、能够应对极端环境及其相关影响的家畜的需求日益增长。日均采食量（DFI）是制定适应力指标（RI）的一个有前景的衡量标准，因为采食量减少被广泛认为是疾病的临床症状。然而，对于哪些基于DFI的RI最具信息量，尚未达成共识。本研究的目的是：（i）评估最常见的基于DFI的RI及其与饲料效率性状（FET）的关系；（ii）研究这些指标与商业农场后代死亡率之间的关系；（iii）深入了解其生物学机制。共使用了1634头健康纯种皮特兰公猪的111121条DFI记录，记录时间从47天到90天不等，每头公猪平均有69条DFI记录。计算了三个RI：残差方差、均方根误差（RMSE）以及偏离预期模式偏差的方差的对数（LnVar）。使用经典动物模型估计每个RI的方差成分，并实施双变量模型估计RI与FET之间的遗传相关性。此外，利用来自55头公猪的6889头后代的数据，对被列为猪繁殖与呼吸综合征高毒力的农场进行了初步死亡率研究。计算了每个当代组（农场和批次）后代的后代死亡率，并将公猪分为三个适应力水平。使用贝叶斯线性模型确定适应力水平之间后代死亡率的差异是否显著。另一方面，对每个RI和FET进行了加权单步全基因组关联研究，共使用了1216个基因型。RI显示出中等遗传力（h = 0.27 - 0.49）以及与FET中等至强的遗传相关性。适应力强的公猪的后代至少有2.5%更高存活率的概率为80%。在RI和饲料转化率中发现了重叠的基因组区域，突出了DOCK1、SYK和SPTLC1基因在调节免疫反应和/或代谢中的潜在作用。偏离群体均值的LnVar是疾病适应力最有前景的指标（LnVar - Pop），因为它是能更好地捕捉后代死亡率差异的RI。此外，这些结果表明RI和FET对育种计划具有共同的生物学基础。需要进一步研究来验证它们。
