Airborne geophysics is temporary and passes quickly over an area. Domestic animals such as horses, cows, and sheep generally do not experience long-term effects from helicopters flying high above the ground.
There is no documented impact on health, reproduction, or behavior has been found from this type of low-intensity overflight.
Sources:
- NLM, “Physiological and behavioral reactions elicited by simulated and intense acoustic stimuli: conclusions indicate goats are unaffected by brief helicopter overflight”, https://pubmed.ncbi.nlm.nih.gov/21496239/
- OSTI.GOV, “Effects of aircraft noise and sonic booms on domestic animals and wildlife: a literature synthesis”, https://www.osti.gov/biblio/6554133