Salivary cell-free HSD17B1 and HSPA1A transcripts as potential biomarkers for estrus identification in buffaloes (Bubalus bubalis)

Estrus detection is a major problem in buffaloes because of the poor expression of estrus signs leading to low reproductive efficiency. Salivary transcripts analysis is a promising tool to identify biomarkers; therefore, the present study was carried out to evaluate their potential as estrus biomarkers. The levels of HSD17B1, INHBA, HSPA1A, TES transcripts were compared in saliva during estrous cycle stages [early proestrus (day −2, EP), late proestrus (day-1, LP), estrus (E), metestrus (ME) and diestrus (DE)] of cyclic heifers (n = 8) and pluriparous (n = 8) buffaloes by employing quantitative real-time polymerase chain reaction (qRT-PCR). The levels of HSD17B1 (EP/DE 1.46–2.43 fold, LP/DE 2.49–3.06 fold; E/DE 7.21–11.9-fold p HSPA1A (EP/DE 0.93–2.39 fold, LP/DE 2.68–3.23 fold; E/DE 8.52–15.18 fold p HSD17B1 (AUC 0.96; p HSPA1A (AUC 0.99; p HSD17B1 and HSPA1A transcripts in saliva during the estrus phase suggest their biomarkers potential for estrus detection in buffaloes.