A Japanese study has shown a link between bovine births and the lunar cycle in domesticated Holstein cows.
The findings follow conflicting reports looking at lunar cycles and the timings of human births and confirm a popular belief that a full moon means births in mammals.
Researchers at the University of Tokyo analysed records of 428 calvings during a three-year period between September 2011 and August 2013.
Birth rate was statistically higher during and near a full moon, and higher for multiparous cows.
It was noted the Holstein unit in Hokkaido “provided a good model” for analysing lunar effects, with lower genetic diversity than other breeds, uniform nutrition and rigorous management conditions.
“Multiple factors, such as the mothers’ nutrition, social environment, and genetic background could disguise the moon’s influence,” said associate professor Tomohiro Yonezawa, graduate school of agriculture and life sciences.
“As vets, we always try to see if questions that are difficult to explore in humans can be examined in farm animals.”
He added that a larger sample size was required for strong conclusions.