Growth Rates and Patterns of Organs and Tissues in the Ovine Foetus

SUMMARY Fifty-six foetuses produced by a flock of healthy, well-nourished ewes were killed between 50 to 140 days after conception and dissected to provide basic parameters of a normal population. Organs and tissues were weighed and measured and the equations for the regression of the values on foetal age evaluated. In general there was found to be a linear relationship between the cube root of organ weight and gestational age. This linear relationship became sigmoid for the weights of the brain, cerebellum and spinal cord. Brain weight and long bone length were the least variable parameters for a given gestational age.