Saliva Crystallization in Cattle: New Possibility for Early Pregnancy Diagnosis?

Saliva sampling is a non-invasive, simple and low-cost procedure. The aim of this study was to confirm the presence and changes of saliva crystallization in domestic cattle during synchronized oestrous cycle and early pregnancy. We verified saliva crystallization as a method for early pregnancy diagnosis. Eight Holstein cows were included into the research. The samples were collected daily from 16^th day before to 34^th day after artificial insemination (in total 51 days). We observed the following types of crystallization: none, dotted, branch-like, fir-like, fern-like and combinations of them and an atypical pattern. We confirmed the presence of saliva crystallization in cattle and its changes during oestrus synchronization process, insemination and post-insemination periods. We found significant differences in pregnant and non-pregnant animals between 20^th and 29^th day after insemination. We concluded that pregnancy diagnosis by saliva crystallization might be possible but the practical application of this method is currently unfeasible.