Daily calving frequency and preterm calving is not associated with lunar cycle but preterm calving is associated with weather conditions in Japanese Black cows.

Yosuke Sasaki,Mizuho Uematsu,Takeshi Osawa,Narumi Kitai,Go Kitahara,Peter J Hansen

doi:10.1371/journal.pone.0220255

Yosuke Sasaki, Mizuho Uematsu + Show 4 more

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https://doi.org/10.1371/journal.pone.0220255

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Abstract

Several external factors including lunar cycle and weather conditions might be associated with calving conditions. Our objective here was to determine the effects of lunar cycle and weather conditions on calving frequency and the occurrence of preterm calving in Japanese Black cows. Calving records were obtained from 905 farms in Miyazaki Prefecture, Japan. Data were collected from 41,116 calvings. We conducted two studies: Study 1 investigated the effects of lunar cycle and weather conditions on daily calving frequency (DCF) with the observational unit of each day and Study 2 investigated those effects on the occurrence of preterm calving with the observational unit for each calving. Preterm calving was defined by whether or not a cow calving before 280 days of gestation, lower 10th percentile of gestation length of the collected data, and by whether or not a cow calving before 289 days of gestation, median of the gestation length. For Study 1, lunar cycle was not associated with DCF in all cows, in only primiparous cows and in only multiparous cows. As well as lunar cycle, weather conditions such as temperature, diurnal temperature variation, the temperature-humidity index, precipitation amount, barometric pressure, relative humidity and solar radiation, were also not associated with DCF. For Study 2, lunar cycle phases were not associated with the occurrence of preterm calving. However, preterm calving was associated with all of the weather conditions (P < 0.05) except for precipitation amounts and solar radiation. Temperature, the temperature-humidity index and relative humidity were positively associated with the occurrence of preterm calving. In contrast, diurnal temperature variations and barometric pressure were negatively associated with the occurrence of preterm calving. In conclusion, the lunar cycle was not associated with DCF and preterm calving, but the weather conditions were associated with preterm calving.

Highlights

In bovine industry, it is crucial for herd managers to predict the onset of parturition because high perinatal calf mortality is related to economic losses and to an animal welfare problem [1]
As an indicator to predict daily calving frequency (DCF), several external factors including lunar cycle and weather conditions have been indicated to be possibly linked to calving conditions
Likewise, adjusted DCF in primiparous or multiparous cows was not associated with weather conditions

Summary

Introduction

It is crucial for herd managers to predict the onset of parturition because high perinatal calf mortality is related to economic losses and to an animal welfare problem [1]. Large farms have several calving events every day, and it is useful to determine the factors affecting daily calving frequency (DCF) to improve management efficiency. No difference was observed in the frequency of child births during various phase of lunar cycle [3]. A different analysis demonstrated that there was no predictable influence of the lunar phases on the frequency of child births [4]. One study reported that lunar cycles were associated with the frequency of spontaneous birth in 428 Holstein cows: the frequency increased uniformly from the new moon to the full moon phase and decreased [6]. Since there has been contradictory findings among different reports in human and sheep, a much larger sample size is likely to be required to achieve an adequate statistical power

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