Ultrasonographic assessment of fetal growth in miniature “Shiba” goats (Capra hircus)

The aim of the present study was to monitor fetal growth in relation to gestational stage to generate formulae which could be used to estimate fetal age in goats. Eight miniature Shiba goats (Capra hircus) were examined weekly by transrectal and transabdominal ultrasound scanning during the gestation period between Day 21 and 126 days of gestation. For accurate judgment, all fetometric parameters were measured at least three times per one examination for each animal. Quantification of the growth of the fetus allowed the development of a number of predictors of fetal age. Low correlations were associated with measurement of the chest diameter (R2 = 0.869), trunk diameter (R2 = 0.8969), tibia length (R2 = 0.8662) and placentome diameter (R2 = 0.8999). Moderate correlation was assessed by calculation of the length of six successive lumbar vertebrae (R2 = 0.9296), femur length (R2 = 0.9278), heart axis length (R2 = 0.9382 and 0.9589; for the longitudinal and transverse axis, respectively), occipitonasal length (R2 = 0.9527), umbilical cord diameter (R2 = 0.9119) and orbit diameter (R2 = 0.9239). A high correlation was estimated in investigating the length of six successive thoracic vertebrae (R2 = 0.9674), braincase diameter (R2 = 0.9831) and crown rump length (R2 = 0.9848). In conclusion, the intrauterine fetal biometry estimation through ultrasound might be useful to predict the accurate gestational age in miniature goats.