Lunar and Climatic Effects on Boar Ejaculate Traits

  • Max F. Rothschild (Iowa State University)
  • Josué Chinchilla-Vargas (Iowa State University)
  • Karl Kerns (University of Missouri)


The present study was designed to investigate the effects of climatic variables, season of the year and moon phases on boars in Artificial Insemination (AI) centers. The time periods chosen were at the initiation of spermatogenesis and at the moment of collection on boar ejaculate traits. Moon phase had a significant effect (P < 0.05) on volume of the ejaculate. Sperm concentration was affected (P < 0.05) by the interaction of moon phase with season, high and low temperature, temperature humidity index (THI), relative humidity (RH), and breed. Season had an effect (P < 0.01) on concentration of sperm. Number of doses was affected by moon phase, season, the interaction between season and moon phase and breed (P < 0.05). An interaction occurred (P < 0.0001) between season and moon phase for volume of ejaculate, sperm concentration and number of doses at date of collection and at day of initiation of spermatogenesis. The significant interaction of season and moon phase on boar semen traits suggests that to maximize productivity of modern swine production systems determining a collection schedule in some seasons relative to moon phase may be advantageous. For example, a collection schedule may be set up to concentrate collections in the fall during last quarter moon phase to maximize the number of doses obtained.

How to Cite:

Rothschild, M. F., Chinchilla-Vargas, J. & Kerns, K., (2019) “Lunar and Climatic Effects on Boar Ejaculate Traits”, Iowa State University Animal Industry Report 16(1).

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Published on
13 Aug 2019