Ultrasonographic monitoring of early pregnancy development in Murrah buffalo heifers (Bubalus bubalis)

The aim of the current study was to monitor the early pregnancy development in buffalo heifers and establish biometric threshold of different gestational vesicle and embryo/fetal parts from the day 15 following fertilization to day 70. Serial daily ultrasonographic examinations were carried out on eleven pregnant buffalo-heifers, during which the gestational vesicle diameter, amniotic vesicle diameter, crown-rump length, trunk diameter and biparietal diameter were measured and embryo/fetal sex characteristics were determined. The gestational vesicle, embryo and its heartbeats were assessed, respectively, by gestational days (d) 20.55 ± 2.34; 25.18 ± 1.91 and 25.27 ± 3.58 of pregnancy. The liquid column in non-pregnant horn and amniotic vesicle were detected, respectively, by d 31.0 ± 3.83 and 31.64 ± 2.34 of pregnancy. Subsequently were sequentially detected the neural tube (d 33.0 ± 3.51), umbilical cord (d 0.25 ± 2.76), early limbs, (d 41.67 ± 4.85), embryos proper movement (d 46.25 ± 2.36), vertebral column (d 47.33 ± 4.9), genital tubercle (d 47.2 ± 3), fetal bones (d 56.56 ± 1.67), brain (d 57.5 ± 1.2), urinary bladder (d 57.88 ± 3.08), stomach cavities (d 59.17 ± 4.36), brain ventricles (d 61.09 ± 2.34), end of migration of genital tubercle in males (d 58.4 ± 2.2) and in females (d 60.4 ± 4.2), skull acoustic shadow (d 59.66 ± 3.13), vertebra acoustic shadow (d 62.14 ± 3.13), ribs acoustic shadow (d 64 ± 2.65), limb bones acoustic shadow (d 65 ± 1.58) and liver (d 66.63 ± 3.54). High regression and correlation coefficients were found between different studied parameters and gestational age, where the highest were found for the crown-rump length and biparietal diameter. In conclusion, the overall data indicated the feasibility and value of ultrasonographic embryo, fetal and vesicle characteristics and embryo/fetometry in buffaloes for the evaluation of fetal development and estimation of gestational age during the first 70th pregnancy days.