Sustainability & efficiency

Feed efficiency in Fleckvieh dairy cows: First insights into genetic relationships

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Abstract

Breeding for improved feed efficiency has been a key focus across multiple species and breeds over the past decade. However, feed intake, which is essential for calculating feed efficiency traits such as residual feed intake (RFI), is not routinely recorded for Fleckvieh (dual-purpose Simmental) cows. One potential alternative is to use existing prediction equations for dry matter intake (DMI) based on production data, such as milk yield (MY) and body weight (BW). Currently, the genetic relationship between predicted dry matter intake (pDMI) and actual DMI in Fleckvieh cows remains unexplored, and little is known about genetic parameters for RFI in this breed. The objectives of this study therefore were to: (1) estimate heritabilities for DMI, pDMI, and RFI, and (2) compare these traits with respect to their genetic correlations and relationships with MY and BW. The data consisted of 82,426 DMI, 82,048 MY, and 32,993 BW records, which were aggregated to 11,675 weekly averages from 268 Fleckvieh cows across three research farms in Austria and Germany. The five-generation pedigree comprised all animals with phenotypic records and their ancestors, resulting in a total of 4,781 animals. The prediction of DMI was performed using an existing equation that incorporated breed, parity, days in milk, milk yield, amount of concentrate, and the average forage energy density. Two approaches were used to calculate RFI: (1) a linear regression model where DMI was regressed on energy-corrected milk yield and metabolic body weight (RFI1), and (2) the difference between DMI and pDMI (RFI2). A multitrait repeatability animal model was applied to estimate genetic parameters for DMI, pDMI, RFI1, RFI2, MY, and BW. The model accounted for the fixed effects of herd, parity, and days in milk, as well as the random effects of herd-trial-test-week, permanent environment, and additive genetic effects of the animal. The heritabilities of DMI (0.18±0.01) and pDMI (0.19±0.02) were similar, and the traits were strongly genetically correlated (0.80±0.04). Their genetic correlations with MY and BW were also similar, although pDMI tended to show slightly higher correlations. RFI1 and RFI2 exhibited lower heritabilities (0.06±0.01 and 0.14±0.02, respectively) but were strongly correlated with each other (0.75±0.09). The correlations of RFI1 and RFI2 with DMI (0.51±0.10 and 0.79±0.03, respectively) were substantially higher than their correlations with pDMI (0.08±0.07 and 0.27±0.07, respectively). In contrast, RFI2 showed lower correlations with MY and BW (0.17±0.11 and 0.17±0.04, respectively) compared to RFI1 (0.52±0.11 and -0.34±0.11, respectively). These findings suggest that pDMI could serve as a useful indirect trait when DMI data are unavailable. Additionally, the RFI traits demonstrated heritabilities and genetic correlations consistent with results reported in previous studies. In conclusion, despite the limited sample size, this study provides valuable first insights that should be validated through further research.

Keywords: 2026

How to Cite:

Burn, S., Egger-Danner, C., Ettle, T., Fuerst, C., Fuerst-Waltl, B., Gerster, E., Guggenberger, T., Huber, V., Linke, K., Steinwidder, A., Terler, G. & Zollitsch, W., (2026) “Feed efficiency in Fleckvieh dairy cows: First insights into genetic relationships”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286352. doi: https://doi.org/10.31274/wcgalp.23949

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