Related Experiment Video
Updated: Aug 7, 2025
11:02
The Use of an Automated System GreenFeed to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals
Published on: September 7, 2015
22.1K
Characterizing ruminal acidosis risk: A multiherd, multicountry study
H M Golder1, S J LeBlanc2, T Duffield2
1Scibus, Camden, NSW, Australia, 2570; Sydney Institute of Agriculture, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, NSW, Australia, 2570.
Journal of Dairy Science
|March 9, 2023
Summary
This study identified three risk levels for subacute ruminal acidosis in early lactation dairy cows. Canadian cows showed lower acidosis risk compared to Australian and Californian herds, highlighting regional differences in dairy cow health.
Area of Science:
- Ruminant nutrition and metabolism
- Dairy cattle health and production
- Microbiome and fermentation science
Background:
- Subacute ruminal acidosis (SRA) is a metabolic disorder affecting dairy cows, impacting health and productivity.
- Understanding SRA risk factors and prevalence across different regions is crucial for effective management.
- Previous models exist for characterizing SRA risk, but require validation in diverse dairy populations.
Purpose of the Study:
- To characterize the risk of subacute ruminal acidosis in early lactation Holstein cows across three distinct geographical regions.
- To utilize a discriminant analysis model to categorize cows into high, medium, and low risk groups for acidosis.
- To investigate the relationship between rumen fermentation profiles, bacterial communities, and production characteristics with acidosis risk.
Main Methods:
- A multicenter observational study involving 261 early lactation Holstein cows from 32 herds in Australia, California, and Canada.
- Rumen fluid analysis for pH, ammonia, lactate, and volatile fatty acid (VFA) concentrations, coupled with bacterial 16S ribosomal DNA sequencing.
- Discriminant analysis using rumen parameters to classify cows into acidosis risk groups; mixed model analyses for production data and regional comparisons.
Main Results:
- 26.1% of cows were classified as high risk, 26.8% medium risk, and 47.1% low risk for acidosis.
- Significant regional differences in acidosis risk were observed: Australia (37.2%) and California (39.2%) had higher prevalence of high-risk cows than Canada (5.2%).
- High-risk cows exhibited characteristics of rapid carbohydrate fermentation, lower bacterial diversity, and altered rumen fermentation profiles (e.g., acetate to propionate ratio) compared to low-risk cows.
Conclusions:
- Rumen fermentation profiles, bacterial phyla abundance, and production characteristics successfully differentiated three acidosis risk states in early lactation dairy cattle.
- Regional variations in diet and management likely contribute to the differing prevalence of acidosis risk observed between Australia, California, and Canada.
- The findings provide a basis for targeted interventions to mitigate acidosis risk and improve dairy herd health and productivity.
