Prevention of Ruminal Acidosis in Cows

Project entitled:

Could the fatty acid profile of milk help us detect and prevent ruminal acidosis in cows ?

Stéphanie Claveau, Débora Santschi, Rachel Gervais


  • Changes in milk production per cow over the last decades is partly due to an increase of feed concentrates in rations, but this increase could also be at the root of a metabolic disease found in dairy herds, namely sub-acute ruminal acidosis.
  • This disease costs the North American dairy industry between US$500 million and US$1 billion per year, or US$1.12 (CA$1.44) per sick cow per day on average.
  • The link between the fatty acids (FA) in milk and rumen health has been demonstrated, but the analyses used to establish this link cannot be used in fieldwork due to their prohibitive costs and the time required to perform them.
  • Thanks to advances in infrared (IR) spectroscopy, we can now determine the FA profile of a milk sample in just a few seconds and at a fraction of the cost of analyses that use gas-phase chromatography (GC).
  • If the results obtained are conclusive, the acidosis test could be part of Valacta’s offer and allow farmers to quickly and inexpensively obtain an overall picture of the risk of sub-acute ruminal acidosis in their herd.
  • For Valacta, this would be an effective way to valorize the analysis while making maximizing the information that can be derived from the milk samples during milk recordings.



The main objective is to develop methods of detecting and preventing sub-acute ruminal acidosis in dairy herds. The project will respond to two specific objectives:

• OBJECTIF 1 – Develop a method of detecting sub-acute ruminal acidosis based on the FA profile of milk through IR spectroscopy using rumen pH
readers. This will make it possible to establish links between the FA profiles of milk and rumen pH.
• OBJECTIF 2 – Determine the causes of sub-acute ruminal acidosis encountered throughout the project to better prevent the development of this
metabolic disease in dairy herds.


Results and potential benefits

Currently, there is no simple and effective method of detecting acidosis in commercial dairy herds. The project will take place on 11 commercial farms in the Lac St Jean region and will allow us to collect data to develop a method of detecting the disease. As part of the project, the FA profiles of milk samples from lactating cows over 1,000 days will be analyzed, for a total of 3,000 samples (two milkings per day and a composite sample of these two milkings).  IR analyses will be performed in Valacta’s laboratories, and the method will be validated through gas chromatography (GC) in Université Laval’s laboratories. The project will result in improved technical and economic performance on dairy farms as a decrease in the adverse effects of sub-acute ruminal acidosis combined with improved feed efficiency will serve to valorize feed. Consequently, improved feed efficiency would result in increased milk production and its components and therefore in increased revenues. Sub-acute ruminal acidosis can lead to other health problems that can require veterinary interventions and the use of medications, which then increases the cost of production and negatively affects the cows’ well-being. Socially speaking, this project is perfectly aligned with the Dairy Farmers of Canada’s “proAction” initiative that was launched in 2013, which focuses on cow comfort and well-being and highlights the importance of considering feed management to ensure their health and well-being. Environmentally speaking, reducing the incidence of sub-acute ruminal acidosis would hopefully improve cow longevity, which would reduce the number of replacement cows that must be bred and therefore reduce associated greenhouse gases (GHG) released in the form of enteric methane. Valacta will make the expected results available as soon as possible at the end of the project to farmers, who will be able to quickly and inexpensively obtain an overall picture of the risk of sub-acute ruminal acidosis in their herd.

Professionals trained

A master’s student will be trained in the Animal Science Department at Université Laval. The student will gain expertise on the methods of measuring rumen pH in dairy cattle (rumen pH readers, FA profile through GC and FA profile through IR spectroscopy), on the interpretation of rumen pH measurements and on the causes of sub-acute ruminal acidosis and ways to prevent this disease.  The student will develop his or her ability to work collaboratively with a research team and dairy farmers.

Financial contributions

Special call for projects in dairy production and dairy processing (2016-2021):
• Consortium de recherche et d’innovation en bioprocédés industriels du Québec (CRIBIQ)
• Natural Sciences and Engineering Research Council of Canada (NSERC)
• Novalait
• 11 dairy farms from Saguenay-Lac-Saint-Jean Region