Beef cattle

Implementation of a National Genetic Evaluation for Female Reproductive Traits in Angus Cattle in Uruguay

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Abstract

In 2025, Uruguay published its first Expected Progeny Differences (EPDs) for female reproductive traits in beef cattle. The foundation for these EPDs was laid in 2016 when Uruguayan National Agricultural Research Institute (INIA) launched SRGen, a web-based total herd data recording system for beef cattle breeders that integrates animal and pedigree information from the national herdbook with breeding, calving and production data provided directly by breeders. Genotype data were obtained from MGAdbSNP, a genomic database managed by INIA that consolidates animal genotypes from breed associations, herd book and research reference populations. Analyzed traits were calving success and days to calving in heifers aged between 20 and 33 months at first breeding. Genetic parameters were estimated using a univariate animal linear model for each trait, including contemporary group and age in months as a linear covariate. Heritability estimates for calving success were 0.06 (SD = 0.02) and for days to calving 0.06 (SD = 0.01). For genetic prediction, we applied SSGBLUP as implemented in BLUPf90+ using the same fixed effects and heritability estimates. Records from 8,022 heifers born between 2013 and 2021 and included heifers bred between 12 and 19 months of age (less than 20% of the data). Most heifers (98%) had complete pedigree information, and 10% had genotype information. Data came from 860 sires (321 genotyped) and 4,219 dams (688 genotyped). Final analysis included all available data and genotypes, and a pedigree depth of 3 generations, totaling 39,777 animals and 11,628 genotypes. Calving Success EPDs ranged from 3.8 to -3.5, and Days to Calving from -3.3 to 2.9 (5th and 95th percentile). Accuracy for heifers with own data ranged from 0.02 to 0.19 (average 0.07) for non-genotyped and 0.02 to 0.15 (average 0.09) for genotyped. For sires with 10 or more daughters, accuracies ranged from 0.06 to 0.47 (average 0.17 for genotyped and 0.14 for non-genotyped sires). Obtained EPD differences were considered sufficient to distinguish animals though accuracies were generally low. Genotyping improved accuracy only marginally, as expected given the small reference population. Since August 2025, the official publication of genetic merit for fertility traits has been available, enabling genetic improvement relevant to our production systems, and encouraging breeders to record more information and thus improve future genetic predictions and possible expand evaluations to additional traits, including second-year breeding and longevity.

Keywords: 2026

How to Cite:

Ravagnolo, O., Aguilar, I., Pravia, M., Carracelas, B., Navajas, E., Quintans, G. & Lema, O., (2026) “Implementation of a National Genetic Evaluation for Female Reproductive Traits in Angus Cattle in Uruguay”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286887. doi: https://doi.org/10.31274/wcgalp.24156

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