Peerayut  Nilchuen, 
    Use of salivary fern patterns for early pregnancy diagnosis in beef cattle,
    Journal of Animal and Veterinary Advances,
    Volume 21,Issue 2,
    2022,
    Pages 34-39,
    ISSN 1680-5593,
    makjava.2022.34.39,
    (https://makhillpublications.co/view-article.php?doi=makjava.2022.34.39)
    Abstract: <p>We examined the presence of and changes in saliva fern patterns in&nbsp;beef cattle during estrus and early pregnancy in 114 cyclic cows in the postpartum period. Saliva samples were collected on the day of artificial insemination (AI) and day 21 post‐AI and assessed microscopically. Saliva fern patterns were classed as: No fern, dotted fern, star‐like fern, branch‐like fern and fern‐like fern. Pregnant cows were examined on day 21 post‐AI and serum progesterone was analyzed by immunoassay. Rectal palpation on day 60 post‐AI to reconfirm the pregnancies revealed that 47 cows were non‐pregnant and 67 were pregnant. Serum progesterone levels &gt;2.5 ng mL<sup>-1</sup> on day 21 post‐AI to diagnose pregnancy showed 100% accuracy in non‐pregnant cows and 85.07% accuracy in pregnant cows. The fern pattern of saliva on AI day showed only fern pattern (0% no fern). However, there were no significant differences in the salivary fern patterns of non‐pregnant and pregnant cows on the day of AI (p&gt;0.05). We found significant differences in the salivary fern pattern between pregnant and non‐pregnant cows on day 21 post‐AI&nbsp;(p&lt;0.05), with non‐pregnant cows showing only fern pattern (0% no fern), where as both no fern and fern patterns appeared in the saliva of pregnant cows. The no fern pattern observed in saliva on day 21 post‐AI method confirmed pregnancy in 29.85% of pregnant cows. Early pregnancy diagnosis using salivary fern pattern maybe possible, however, its practical application is currently unfeasible.</p>

    Keywords: Beef cow; Early pregnancy; Saliva; Fern pattern; Serum progesterone