Estimation & Prediction

Calving traits in Norwegian Red x Beef crosses: First genetic analysis

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Abstract

The use of beef semen in dairy herds has increased in Norway over the last decade. While most international research on Beef-on-Dairy focus on Holstein, the Norwegian Red (NRF) is the predominant dairy breed in Norway. Given that Norwegian Red has been selected for fertility, health and moderate body size, calving trait expressions in Beef-on-Dairy crosses may differ from those reported in Holstein-based systems. As the use of beef sires on NRF cows becomes common, there is a need for genetic evaluation of beef sires for crossbreeding performance. Especially the evaluation of calving-related traits is crucial both for animal welfare and production efficiency. The objective of this study was to estimate variance components and heritabilities for calving traits of Norwegian beef sires used on NRF dams. The data included offspring born since 2016 with a total of 23 468, 11 871 and 9 026 crossbred calves, and 185 032 purebred Norwegian Red calves. The traits analyzed were stillborn or dead within 24 hours, calving ease, calf size, and gestation length. Stillbirth is a binary trait (0 for alive at birth and 1 for dead within 24 hours). Calving ease is evaluated on a three-point scale, where 1 is no difficulty, 2 moderate, and 3 severe difficulty Calf size is scored 1 for small, 2 for medium, and 3 for large calves. Gestation length is defined as the number of days between successful insemination or mating and calving. All calving traits were recorded by the farmer. The pedigree file used for the analysis contained 601 869 animals in total. Variance components were estimated using the DMU software package, applying single-trait animal models. The statistical model for calving ease and calf size included fixed effects of birth month, twinning, herd-year, calf sex, sire breed, and a regression on age of dam within each calf sex-sire breed combination. The estimated heritabilities were 0.13± 0.007 for calving ease and 0.34± 0.008 for calf size. For gestation length, the estimated heritability for gestation length were 0.55 ± 0.006.There were significant differences in gestation length among the four breeds, with the largest difference in estimated gestation length between Limousin and Norwegian Red, corresponding to approximately five days. This study provides the first genetic evaluation of calving traits in Norwegian Beef-on-Dairy crosses with Norwegian Red dams and major beef sire breeds in Norway. The results show clear genetic variation and demonstrate that calving performance can be improved through informed selection of beef sires. This provides a foundation for developing more robust genetic evaluation and improving both calving management and production efficiency in Norwegian Beef-on-Dairy systems.

Keywords: 2026

How to Cite:

Hamfjord, i., Heringstad, B., Moghadam, H. & Furre, S., (2026) “Calving traits in Norwegian Red x Beef crosses: First genetic analysis”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286644. doi: https://doi.org/10.31274/wcgalp.24075

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