A support for a casing containing a detector for detecting estrus in cows. The support comprises a natural fiber patch having a surface area in the range from approximately 0.04 m.sup.2 to approximately 0.06 m.sup.2 which supports a substantially rectangular case which receives the detector and is placed substantially at the center of the patch. The detector for detecting estrus in cows is housed in a casing supported by the support. The support comprises a baseplate capped by a cover.