Gestational Age Estimation in Kari Sheep Using Non-conventional Ultrasonographic Parameters

The present study was designed to determine gestational age in Kari ewes measuring of non-conventional foetal growth parameters i.e., Abdominal Circumference (AC), Foetal Heart Beat Rate (FHBR) and Femur Length (FL).The experiment conducted at different gestational age in Kari sheep with a B-mode ultrasonograph and a 3.5 MHz transducer. The ewes were scanned in dorsal recumbency over a restraining chute with post-scanning shaving of the inguinal regions.Data were collected from 49 ewes. Based on varying length of gestation, Kari ewes were divided into seven categories A, B, C, D, E, F and G representing gestation length of <100, 101-110, 111-120, 121-130, 131-140, 141-150 and > 150 days, respectively. Abdominal Circumference (AC), Femur Length (FL) and Foetal Heart Beat Rate (HBR) were observed at weekly interval throughout gestation. Regression equations for each parameter against the Gestational age of the foetus presented in trend lines using bi-nomial regression analysis. Mean Abdominal Circumference for all categories in week 4 was 54 mm whereas the same for B was 66 mm. The correlation between gestational age and AC was 0.68 which was significant (P< 0.05. Mean Femur Length for all categories in week 3 was 17 mm whereas the same for D was 17 mm. The correlation between gestational age and FL was 0.58 which was very highly significant (P< 0.001). Mean Foetal Heart Beat Rate was 155.5 throughout the gestational life. The earliest Heart Beat was observed in the third week of gestation in category A. Early Heart Beat Rate detection indicated life when bestowed into the embryo / foetal viability. The higher coefficients of determination (R 2 ) and correlations for AC and FL with gestational age (wk) suggest its reliability to estimate foetal age in Kari sheep.