Celebrating a Decade of Dairy Science with Arbor Assays’ Cortisol ELISA Kit 

In celebration of Cow Appreciation Day, we’re reflecting on how Arbor Assays’ Cortisol ELISA kit has been helping to advance dairy science for the past decade. In fact, our Cortisol ELISA Kit has been used in over three dozen cattle and dairy cow studies since 2014!  

One notable study validated the use of this kit to measure stress levels in dairy cows through hair samples. This method has offered researchers a noninvasive, reliable way to assess long-term stress and ensure better welfare for these gentle giants. 

Splitting Hairs 

Researchers collected hair samples from the heads of seventeen Holstein-Friesian dairy cows. The hair was initially clipped and allowed to regrow over a 25-day period before being collected. The researchers suspected hair color may be a factor, so they kept black and white hair separate for analysis.  

They also collected Fecal samples twice a week over the same 25-day period to compare cortisol metabolite levels, providing a comprehensive view of the cows’ stress over time. 

The team extracted and measured cortisol levels using the Arbor Assays Cortisol ELISA Kit (K003-H). Hair samples were washed, dried, and cut into small fragments before cortisol extraction. The extracts were reconstituted with buffer provided by the kit and analyzed. 

A Colorful Twist: Hair Cortisol Correlates with Fecal Metabolites  

The study yielded some significant findings: 

• Correlation with Fecal Cortisol Metabolites: The researchers found a strong correlation between cortisol levels in fecal and white hair samples. This confirms the validity of using hair to assess long-term cortisol exposure. 

• Color Variation: Cortisol concentrations differed significantly between black and white hair samples, with black hair showing higher levels. This underscores the importance of sample homogeneity and the need to validate each sample type for accurate results. 

• Validation Metrics: The intra-assay and inter-assay coefficients of variation were 4.9% and 10.6%, respectively, with an extraction efficiency of 89.0%, highlighting the method’s reliability and accuracy. 

Cortisol’s Impact Down the Food Chain 

This study marked a significant advancement in animal welfare research, providing a non-invasive, reliable method to monitor long-term stress in dairy cows. Researchers and farmers can better understand and manage their herds’ welfare by leveraging the Arbor Assays Cortisol ELISA Kit, ensuring healthier and happier cows. 

Cattle are crucial to our food supply. However, cattle farming remains one of the most resource-intensive food sources, negatively impacting the environment. Studies like these, which emphasize reducing cow stress and improving well-being, are hopeful steps toward lowering resource costs and enhancing the quality of meat and dairy products. Improving animal welfare contributes to more sustainable farming practices and a healthier planet. 

Discover our full range of ELISA kits and delve into the wealth of research celebrating cows on our website. Happy Cow Appreciation Day!