Melatonin supplement for cattle found to have health benefits, say scientists.

Those in need of extra sleep often reach for a bottle of melatonin, but Mississippi scientists are discovering a host of other proven and potential health benefits for cattle that receive the supplement.

Faculty and students at Michigan State University’s Department of Animal and Dairy Sciences and the Agricultural and Forestry Experiment Station in Mississippi are making interesting discoveries about the functions of melatonin in the body of cows and how this hormone can help support the health of cattle.

Michigan State University Assistant Professor Caleb Lemley has a long history of studying the use of melatonin as a dietary supplement for cattle. He has been studying how the hormone affects blood flow between the mother and fetus during pregnancy for nearly a decade.

“Over the years, we’ve looked at the antioxidant benefits of melatonin, which helps relieve oxidative stress in animals and has implications for cardiovascular health,” Lemley said.

“Summer heat is a huge stressor for cattle, and in our research here in Mississippi, we found that melatonin can be used to control the animal’s body temperature,” added Postdoctoral Fellow Zoli Contreras Correa. “At night, when melatonin levels are highest, body temperature is lowest. Our recent research showed that melatonin supplementation during the summer reduces body temperature in pregnant cows, so we hope to conduct further research in other types of cattle.”

Because melatonin controls the body’s circadian rhythm and responds to light, levels also fluctuate throughout the year, being naturally higher in the winter and lower in the summer.

“We just completed a study comparing melatonin supplements given to cattle living in Montana with our own at MSU during the winter months, and the differences were notable,” Lemley said. “We saw a very limited response in Montana cattle compared to Mississippi cattle, so we think these treatments may be more effective in the Southeast.”

PhD students Riley Meissman and Rebecca Swanson are also involved in melatonin research.

The scholars recently published a literature review in the journal Biomolecules entitled “Melatonin in health and disease: an animal production perspective. These scientists examined more than 100 studies over six decades to show that this hormone — which is produced naturally in the brain — works in ways beyond its primary function of regulating the circadian rhythm.

One of the most recent discoveries about melatonin is its effect on the microbiome, the bacterial communities that live inside the body. In her graduate studies, Meissman conducted research looking at its effect on the microbiome of the bovine vaginal tract.

“Melatonin levels fluctuate throughout the day and throughout the year, and so do bacteria,” Messman said. “So, melatonin changes the microbiome and the immune system, which plays a huge role in every physiological process you can think of.”

As part of her postgraduate work, Swanson researched the role of melatonin in skeletal muscle development.

“Nutrient restriction occurs naturally in certain regions of the United States and at certain times of the year,” she said. “Melatonin can help alleviate some of those dietary restrictions and promote more efficient amino acid production and muscle growth.”

Because melatonin is considered a supplement and has not been approved by the Food and Drug Administration, there has been a limited amount of research on it’s full effects and potential benefits. And while it is currently a legal supplement for show animals, food animals may not legally receive melatonin supplements. Lemmly stressed that it is unlikely that the effects of the supplement were present in the muscle tissue at the time of treatment.

“Melatonin has a rapid rate of clearing and will leave the body within a day,” he said. “When you think about that and the low cost of a 25-cent-a-day cattle supplement, there are a lot of potential benefits for producers.”

There is still much to be discovered about the far-reaching ways in which melatonin can support the health of cattle simply by manipulating levels of this naturally occurring hormone through supplementation. MSU scientists will continue their work to discover more about its benefits.