Imagine cattle living in Brazil, where temperatures range from 95 to 104 degrees Fahrenheit year-round, suffering from grave heat exposure. Fast shallow breathing, profusely sweating, drooling and panting as they overheat, walking less, looking for shade and drinking triple the amount of water. As a practicing veterinarian in Pará State, this was an unforgettable sight I couldn’t unsee.
Heat stress isn’t just an abstract problem. Cattle undergo major physiological changes to survive extreme heat, similar to how the human body responds to a run on a hot summer’s day. Their cardiovascular system constricts as blood supply diverts from the vital organs towards the periphery. While this is a great way to increase body cooling, it interrupts oxygen supply to the intestines. Reduced oxygen disturbs the intestinal cells. In consequence, contents that once were inside the intestines such as bacteria, are released into the blood circulation. This syndrome – known as “leaky-gut” – is one of the many challenges that climate change brings to dairy farming.
Heat stress is not a challenge that only cattle in Brazil face, it is global issue affecting agricultural systems across the world. In the United States, heat stress can cost the dairy industry a staggering $1.5 billion dollars annually. Recent predictions project those economic losses may rise an additional $126 million over the next 50 years. These financial losses are driven by reduced milk production, pregnancy losses, disease and in severe cases, death.
At Cornell University, I am investigating the interactions between the gut microbiome and heat stress to define the role that gut microbes play in explaining the physiology of heat stress. This will help us understand why some animals are more heat resilient than others and enable researchers to develop nutritional therapies that mitigate the effects of heat stress. Currently, we are exploring organic acids and plant botanicals as dietary supplements for lactating dairy cows. These compounds are known for their intestinal healing properties in poultry and swine production but require testing in cattle. Organic acids and plant botanicals are naturally-occurring and represent one of the ways to improve the welfare of cattle, enhance gut health and potentially lower antibiotic usage in dairy herds.
During the initial phase of my research program, our team took care of 62 dairy calves undergoing heat stress, supplementing their diet with different dietary levels of organic acids and botanicals. In this phase, we identified the best dose to further explore as we move forward to the next phase of testing: supplementing lactating cows. Looking forward to the next stage, we can test whether our preliminary results in calves are similar in cows. As data analyses unfold, stay tuned for our beat the heat updates!
Agriculture isn’t a one-person job and for that I am very fortunate to have the sponsorship from FFAR and my industry sponsor, VetAgro Inc. I am also grateful to have the support of mentors through the FFAR Fellows program, as well as the technical expertise and research excellence from my supervisors and advisory committee.
The approaches I am taking during my program represent sustainable alternatives to alleviate effects of heat stress, improve health and performance of dairy cows and ultimately ensure that good quality products are put on the consumer’s table.
