Sustainability & efficiency

Genetic Parameters for Dry Matter Intake, Methane Emissions, Nitrogen Excretion, and Carcass Traits in Hereford Cattle

---

Abstract

The objective of this study was to estimate heritabilities and evaluate genetic and phenotypic correlations among three environmental sustainability traits-dry matter intake (DMI), methane (CH₄) emission rate (g/d), and blood urea nitrogen (BUN)-and carcass traits including hot carcass weight (HCW), ribeye area (REA), marbling (MARB), backfat (BF), and yearling weight (YWT) in a population of Hereford cattle. Enteric methane and nitrogen excretion are major components of the beef industry's environmental footprint, while DMI influences both nutrient metabolism and environmental efficiency. Understanding the genetic relationships among feed intake, nutrient utilization, and carcass composition is critical for identifying animals that are both productive and environmentally sustainable.Data were collected on 783 animals (83 bulls, 692 steers) from 2021 through 2024. DMI was measured using Vytelle feed intake units, CH₄ emissions were measured with GreenFeed systems, and BUN was quantified from serum samples using a colorimetric assay. Methane data were filtered using parameters (≥40 valid visits, airflow > 26 L/s, temperature > -10 °C) to ensure data quality. Carcass data were collected postharvest. A series of single- and multi-trait animal models were fitted in ASReml 3.0. Fixed effects included trait-specific contemporary groups and age at measurement with animal as an additional random effect.Heritability estimates were low for BUN (0.17 ± 0.17) and CH₄ (0.15 ± 0.16), and high for DMI (0.51 ± 0.14), indicating potential for genetic improvement. DMI exhibited strong positive genetic correlations with HCW (0.75 ± 0.11), YWT (0.82 ± 0.09), MARB (0.63 ± 0.32), and BF (0.53 ± 0.19). BUN showed moderate/high positive genetic correlations with HCW (0.26 ± 0.50), MARB (0.64 ± 0.44), and BF (0.47 ± 0.14), and a moderate negative correlation with REA (-0.31 ± 0.67), indicating that animals with lower BUN concentrations (greater nitrogen use efficiency) tend to have larger ribeye areas and greater fatness and marbling. CH₄ demonstrated weak to moderate genetic correlations with HCW (0.15 ± 0.48), REA (-0.15 ± 0.66), MARB (-0.38 ± 0.50), and BF (0.55 ± 0.48), suggesting limited shared genetic control between methane emissions and carcass composition. Phenotypic correlations followed similar patterns but were generally lower in magnitude. A positive relationship between DMI and CH₄ was observed both phenotypically (0.40 ± 0.06) and genetically (0.66 ± 0.46), confirming that higher feed intake contributes to greater methane emissions.In conclusion, DMI, BUN, and CH₄ are heritable and genetically correlated with carcass traits, highlighting opportunities to simultaneously improve environmental efficiency and carcass merit. Selection for animals that efficiently utilize feed and nitrogen while maintaining carcass quality may reduce methane and nitrogen outputs in beef production. Continued validation across larger, multi-breed populations is warranted to inform breeding strategies that balance productivity and sustainability.

Keywords: 2026

How to Cite:

Bedwell, P., Enns, R., Griffin, M., Sanders, S. & Speidel, S., (2026) “Genetic Parameters for Dry Matter Intake, Methane Emissions, Nitrogen Excretion, and Carcass Traits in Hereford Cattle”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2283480. doi: https://doi.org/10.31274/wcgalp.23502

Rights: 1