Development of the Bovine Metanephros

This study presents the gross and light microscopic features of the developing bovine metanephros. Thirty-six specimens, consisting of 19 whole embryos and foetuses, 15 foetal metanephroi, one calf kidney and one cow kidney, were examined. The development of the collecting duct system and nephron induction and formation were similar to those processes described for the human kidney but appeared to follow an accelerated time course. The bovine metanephros by 15–18 weeks gestation, had a well organized internal structure consisting of dilated major calyces, prominent minor calyces and papillae, and a definize cortex and medulla. Nephron induction started as early as 4–6 weeks gestation and was completed around 28 weeks.