Bio-patch and related methods for detecting fertility condition in cows. In some embodiments, a patch can include a patch substrate configured to support a plurality of components, and to allow the patch to be attached to a cow. The patch can further include a detector implemented on or at least partially within the patch structure, and configured to detect one or more conditions associated with a fertility cycle of the cow. The patch can further include an interface component implemented on or at least partially within the patch structure, and in communication with the detector. The interface component can be configured to transmit information related to the one or more conditions, such that the information allows estimation of occurrence of a standing estrus window for the cow.
