Near Infrared Spectra of Body Fluids Reveal the Relationship between Water Spectral Pattern and the Oestrous Cycle

Abstract

Currently, more than 20% of extant mammal species are on the verge of extinction. 1 For most of them, in situ conservation is difficult, mainly due to the destruction of their habitat. Therefore, instead of in situ conservation, the demand for ex situ conservation is rapidly increasing. To maintain a certain number of individuals of a given species in captivity without compromising genetic diversity, it is necessary to manage the populations through appropriate breeding programmes. In order to promote breeding in captivity, it is important to estimate the density distribution of fertile individuals and the female oestrous status for breeding. Therefore, there is a need for an analytical method which facilitates easy daily monitoring of oestrus. Near infrared (NIR) spectroscopy has been applied for the rapid and non-invasive qualitative and quantitative analysis of materials in the livestock, agricultural and medical fields. Recently, various groups have tried to use it for species identification and sex discrimination by faecal NIR spectra in captive and wild animals. 2–4 Also, in