Peri-follicular blood flow in the follicle from which ovulation occurs in cows.

The hypothesis of the study was that the vascularity of ovulatory follicles (OF) determines the ovulatory status. The peri-follicular blood flow characteristics of OF were sequentially recorded using Color Doppler Imaging ultrasonography from the onset of induced estrus (Day 0) to ovulation at 12 h intervals. The OFs were categorized into two groups based on the timing of ovulation (i) Normal ovulation (OFN) - When ovulation occurred within 36 h after the onset of estrus (n = 18) and (ii) Delayed ovulation (OFD) - When ovulation occurred after 36 h (n = 15). The blood flow velocity, Doppler pulse duration (DPD) and Pulsatility index (PI) of the OF were recorded during each examination. The OF was well vascularized with a detectable blood flow signals, while the subordinate or atretic follicles were devoid of detectable blood flow. On Day 0, the DPD (874.33 ± 56.99 ms) and PI (0.62 ± 0.01) values were less in the OFN when compared to OFD (1140.56 ± 27.54 ms and 1.28 ± 0.15 respectively) group. In the OFD group, ovulation occurred between 36 and 60 h after onset of estrus when the DPD value reduced to 878.17 ms. Based on ROC analysis, it was evident that the DPD value of < 929 ms is a necessary factor for induction of ovulation. The decreased DPD and PI values of the OF on the day of estrus are positive indicators of a normal ovulation process.

Evaluation of pheromone-based kit: A noninvasive approach of estrus detection in buffalo.

In view of the silent nature of estrus in buffalo, a noninvasive assay kit has long been felt necessary for easy and effective estrus detection. This study was designed to detect estrus in buffalo using a kit formulated in our laboratory based on pheromone compound. Group I: Urine samples collected at estrus phase and group II: randomly collected urine samples were subjected to the test using the kit. No colour developed (i.e., positive reaction) in estrus urine after adding the kit solution. By contrast, pale and/or dark pink colour developed (i.e., negative reaction) in urine from the proestrus and diestrus buffaloes, respectively. Field evaluation of the kit in groups I and II revealed that 60.87% and 71.43% of urine samples were correctly identified as estrus and nonestrus (i.e., proestrus and diestrus), respectively. Therefore, the first of its kind estrus detection kit formulated based on urinary pheromone can as well be used as a simple device to detect estrus in buffalo.