Swine

Genetic evaluation of caliper-based body condition measured across multiple reproductive stages and their relationships with maternal traits in Large-White sows

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Abstract

The caliper-based body condition measurement (BCC) is a widely used indicator of backfat, muscle mass, and body weight in animals. BCC can be consistently assessed across multiple life stages, providing a standardized and cost-effective approach for monitoring animal status. Furthermore, understanding the genetic basis of BCC and its changes across lactation can provide insights for improving sow productivity and welfare. Therefore, the objectives of this study were to estimate variance components for caliper-based body condition measured in sows across multiple life stages, to assess BCC change (BCC_C) throughout lactation, and to investigate the genetic relationships among these BCC traits and key maternal traits. After editing and quality control, 38,774 BCC records from 11,988 animals and 43,773 SNP were used for the analyses. BCC_C was calculated as the difference between body condition scores measured at weaning (BCC-WN) and at due-to-farrow stage (BCC-DTF), where more negative values indicate greater body condition loss during lactation. Only animals with records for both stages within the same parity were considered for the calculation of BCC_C. Records with BCC_C values lower than -6 or higher than +6 were excluded from the analyses. Genetic parameters were estimated based on three Bayesian animal models: (i) single-trait animal model considering BCC_C, (ii) a repeatability model fitting all BCC records, and (iii) a multi-trait model considering BCC-DTF, BCC-WN, and BCC measured at pregnancy check (BCC-PG) as distinct traits. The genetic correlations between BCC and BCC_C with maternal traits, including the number of piglets born alive (PBA) and the number of piglets weaned (PW), were also estimated. The systematic effects included stage of measurement (repeatability model), parity number, contemporary group (week-year at measurement and farm), age at first farrowing, and lactation length. The heritability estimates for BCC-DTF, BCC-WN, and BCC-PG were 0.22(0.01), 0.26(0.01), and 0.24(0.01), respectively, while their repeatability estimates were 0.44(0.01), 0.46(0.01), and 0.45(0.01). The heritability of overall BCC was 0.19(0.01) with a repeatability of 0.39(0.01). The heritability (PSD) for BCC_C was 0.10(0.01). All stage-specific BCC traits were highly correlated [BCC-WN and BCC-PG: 0.97(0.01); BCC-DTF and BCC-WN: 0.86(0.01); and, BCC-DTF and BCC-PG: 0.93(0.01)]. The genetic correlations between BCC and maternal traits were of low magnitude, 0.10 (0.06) for PBA and -0.05(0.09) for PW. The genetic correlation (PSD) between BCC_C and PBA and PW were -0.31(0.23) and -0.08(0.10), respectively. In conclusion, caliper-based BCC is a heritable trait with substantial additive genetic variance. BCC records collected at different reproductive stages are highly correlated at the genetic level, supporting the use of a repeatability model for practical implementation in breeding programs. Additionally, BCC_C is genetically correlated with maternal traits, indicating its potential use as an auxiliary trait for improving maternal performance.

Keywords: 2026

How to Cite:

Benfica, L., Bhatnagar, A., Chen, C., Holl, J., Szulowska, L., Schinckel, A. & Brito, L., (2026) “Genetic evaluation of caliper-based body condition measured across multiple reproductive stages and their relationships with maternal traits in Large-White sows”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286763. doi: https://doi.org/10.31274/wcgalp.24112

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