Lunar cycle affects timing of birth in cows

August 31, 2016, University of Tokyo
The study looked at the timing of spontaneous (not induced) births among Holstein cows. Credit: Copyright: The University of Tokyo, Photo Credit: Dr. JY Li, The University of Tokyo

A popular belief that there is a higher number of births around the full moon has been shown to be true for dairy cows by a group of University of Tokyo researchers.

Previous studies have found conflicting evidence on the moon cycle affecting the timing of human births and many researchers remain unconvinced that the moon influences human births.

Associate Professor Tomohiro Yonezawa of the Graduate School of Agriculture and Life Sciences explains that the results may have varied because "multiple factors, such as the mothers' nutrition, social environment, and genetic background could disguise the moon's influence. However, cows may provide a good model for teasing apart the lunar effect from other factors that also influence birth."

In the present study, Yonezawa and his colleagues analyzed the birth timing of genetically similar Holstein cows reared in uniform conditions on a dairy farm in Hokkaido, northernmost prefecture in Japan. The researchers looked into 428 records of full-term spontaneous cow deliveries during a three-year period between September 2011 and August 2013, and the state of the moon in the moon cycle at the time of each delivery.

Analysis showed that the birth rate was statistically higher during the near full and full moon. Furthermore, the number of deliveries was higher for cows that had previously given birth.

"As vets, we always try to see if questions that are difficult to explore in humans can be examined in farm animals. This study is a good example of how we've put this approach into practice, but before we can draw any strong conclusions, we have to verify our results with a larger sample size," says Yonezawa. "Also our findings do not immediately hold true for human births and we still don't know why the number of calves delivered increases around the . However, we are excited to do further research because the findings should eventually lead to discoveries that can be generalized to human births."

There was a significant peak in spontaneous deliveries between the waxing gibbous and full moon phases. Credit: CC-BY (4.0) Yonezawa et al.

Explore further: Stop blaming the moon: Study highlights flaws in earlier research on hospital admissions and the lunar cycle

More information: Tomohiro Yonezawa, Mona Uchida, Michiko Tomioka & Naoaki Matsuki. Lunar cycle influences spontaneous delivery in cows. PLOS ONE, DOI: 10.1371/journal.pone.0161735

Related Stories

Rare full moon on Christmas Day

December 17, 2015

Not since 1977 has a full moon dawned in the skies on Christmas. But this year, a bright full moon will be an added gift for the holidays.

Does the moon affect our mood or actions?

May 6, 2016

Always surrounded by an aura of mystery, the moon and its possible influence over human behavior has been object of ancestral fascination and mythical speculation for centuries. While the full moon cannot turn people into ...

Happy cows make more nutritious milk

July 15, 2016

Daily infusions with a chemical commonly associated with feelings of happiness were shown to increase calcium levels in the blood of Holstein cows and the milk of Jersey cows that had just given birth. The results, published ...

Recommended for you


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.