Study on Various Luteal Characteristics Using Doppler Ultrasonography for Early Pregnancy Diagnosis in Nili-Ravi Buffaloes.

The objective of current study was to assess the trend in various luteal characteristics viz luteal size (LS), plasma progesterone (P 4 ) concentration, and luteal blood flow (LBF) using color Doppler imaging (CDI) and power Doppler imaging (PDI) modes in pregnant and nonpregnant Nili-Ravi buffaloes. Lactating, cyclic, and healthy Nili-Ravi buffaloes ( n = 09) without any reproductive abnormality were selected in present study. Buffaloes were synchronized using Ov-Synch, and fixed-time artificially insemination was performed (day = 0). Pregnancy was diagnosed on 30-day post-AI using B-mode ultrasonography based on presence or absence of embryonic heartbeat. Ovaries of all animals were scanned from day 5 till 21 post-AI using both B-mode and Doppler ultrasonography to measure LS and LBF. After each ovarian ultrasound examination, blood samples were collected via jugular venipuncture to determine plasma P 4 concentration. According to results, LBF using CDI and PDI was significantly higher ( P ≤ 0.05) in pregnant buffaloes on days 13 and 15 post-AI, respectively. The mean LS and plasma P 4 concentration did not differ ( P ≥ 0.05) between pregnant and nonpregnant animals until day 15 post-AI. However, a significant difference ( P ≤ 0.05) was noticed for both on day 17 and onwards. It is concluded that LBF is a more sensitive luteal character as compared to LS and P 4 for earlier pregnancy diagnosis in Nili-Ravi buffaloes when ascertained through CDI.